It’s time to work on DIY’ing your tile shower and you’re not looking forward to working with the dreaded cement board again. It’s dusty, crumbly, and hard to start screws into. Not to mention how heavy it is.
Sure, there are waterproof foam backer boards on the market but they are extraordinarily expensive. Further, you know you can’t put drywall in a shower. So what to do?
Well, this is an area in which GoBoard is quite compelling: It costs significantly less than other foam backer boards yet is much easier and simpler to install than cement board.
What’s the catch? We’ll get to that. But first…
Johns Manville, the maker of GoBoard Tile Backer Board had originally sponsored this post. Additionally, this post may contain affiliate links. The site owner may earn a commission should you click on an affiliate link and make a purchase. Read more
Estimated reading time: 10 minutes
Table of Contents (click to expand)
What is GoBoard Tile Backer Board?
What is GoBoard?
GoBoard tile backer board is made by Johns Manville and is a waterproof foam board that provides a surface to be tiled over.
It’s similar to other foam backer boards in that it has a foam core with a facing attached to it.
It is waterproof. Of course, you’ll have to seal the seams and penetrations like you would with any backer board. But GoBoard itself is waterproof and doesn’t get additional waterproofing added to it.
Finally, GoBoard backer board can be installed on walls or floors. They make a 1/4-inch thick version, especially for use as a floor tile underlayment.
The Video for How to Install GoBoard Tile Backer Board
Why is GoBoard Tile Backer Board compelling?
Unlike some of the other popular foam backer boards that require their own brand of special screws and washers, GoBoard is installed with cement board screws or galvanized roofing nails.
edit: GoBoard fasteners are now available and can be spaced every 8 inches as opposed to 6 inches. They are specifically designed for GoBoard with a bigger diameter head for more holding power.
Additionally, each 3ft x 5 ft sheet weighs about 8lbs. Much lighter than 30lb+ weights of cement board.
Because it’s made out of foam it won’t damage the walls in a home as you’re carrying it upstairs which is a common occurrence with cement board.
Then when you factor in the ease of waterproofing, mentioned above, and the cost savings compared to other foam backer boards, you can see how all this adds up to quite a compelling product.
Drawbacks
I see two main drawbacks with GoBoard Tile backer board.
1. A lack of system components.
When I first wrote this post, in 2018, GoBoard was essentially just a backer board. They have since come out with GoBoard shower system as well as many other products. With the GoBoard Wedge system is a way to custom build a shower pan using all GoBoard products.
2. Itchiness
Yes, GoBoard tile backer board is a bit itchy to work with.
Johns Manville is a company that makes building products such as fiberglass insulation. Some of the technology that they’ve developed for their products has gone into the creation of GoBoard.
In the video above, my wearing of long sleeves wasn’t an accident. Long sleeves will help minimize this inconvenience.
2021 update: GoBoard has come out with a new backer board with unique characteristics, one of which is that it doesn’t have the itching issue. However, due to the pandemic and supply shortages, the production of it is on hold for the time being.
How to install GoBoard Tile Backer Board: Two methods
The first method is the way that is outlined by other foam backer board manufacturers. This is where you apply a sealant to every edge prior to installing the backer board.
For example, you would apply a bead of sealant to the top of the tub flange- then install GoBoard over it. Then apply more sealant on top of that sheet and install another sheet on top of it.
The video below demonstrates this method:
In this post, and my video, I’m going to demonstrate the second method: Install all the GoBoard first- then apply all the sealant afterward.
Install First; Seal later
The advantages of installing GoBoard this way are that you’re not constantly going from the sealant to the install.
I like to wear rubber gloves when applying any sealant and I find it preferable to put them on one time and tackle the goopy part all at once.
However, the critical aspect of this is to make sure that you leave a 1/8 inch gap everywhere that you will need to apply GoBoard sealant. Without leaving a gap it’s likely your installation won’t be waterproof.
Tools needed to install GoBoard:
- caulk gun
- cement board screws (or roofing nails or other approved fasteners)
- putty knife
- corner tool (drywall type)
- tool to install fasteners (impact driver, hammer, or ?)
- razor knife
- straight edge for cutting
- denatured alcohol (for cleanup)
And, of course, GoBoard backer board and GoBoard Sealant.
For a list of alternate sealants, please scroll to the bottom of this post.
Before you begin:
Check your framing
You want to make sure that the wall framing meets minimum standards. These include:
- 16 inches on center
- blocking around the base of tub or shower
- All vertical seams and edges supported
Installing GoBoard Tile Backer Board
I was installing the walls around an alcove tub. Since a standard tub is 60-inches wide I don’t think it’s a coincidence that tile backer boards come 60-inches in length.
For the back wall, I laid the panels sideways so they were 36-inches tall. The side walls I installed vertically.
Typically, the back wall pieces get installed first then the sides though this isn’t a hard and fast rule.
How to Cut GoBoard
Cutting GoBoard is a breeze.
For straight cuts, a simple razor knife and straight edge are all that’s needed. It really is this simple:
- Score through the top facing
- Break the panel along this score point
- Snap it back in the opposite direction
The panel will break right off with very little strength needed.
For rounded or angle cuts:
You’ll have to use a razor knife and cut all the way through the board
Fastening GoBoard Tile Backer Board
To fasten GoBoard to the wall you can use:
- GoBoard fasteners (can be spaced at 8 inches)
- Cement board screws
- Galvanized roofing nails
- Staples (consult manufacturer’s data sheet for correct type)
I much prefer screws although they are probably the most time-consuming of the choices listed above. Since it’s easy to drive the screws too deep you’ll have to be careful about how far the screws are installed.
If the screws aren’t screwed in far enough then they will interfere with the sealant and you could compromise the waterproofing of the panels.
If they are driven too far in then they won’t have the holding power.
Screws should be installed on the studs every 6 inches and within 1/2 inch of every edge.
Gaps between the board
You’ll want to make sure that there’s a 1/8 inch gap between all Goboard seams. This includes between Goboard and the tub (or shower) flange and also the vertical corner seams. This will allow the sealant to get in between these two points.
Applying GoBoard Sealant
GoBoard makes their own sealant for their Goboard panels. It comes in standard 10.3 oz caulk tubes and is applied with a caulk gun.
Cut the tip of the caulk tube off at an angle. The hole in the tube should be small enough to fit in between the 1/8 inch gap. Don’t forget that there’s an inner seal in the neck of the tube and this will need to be stabbed with a metal wire (often included, but not always, on caulk guns).
The sealant will be put into every gap around the panels. Every panel installed should have a 1/8 inch space all around it.
Two passes
I recommend that GoBoard sealant is applied in two different passes.
The first attempt should be to concentrate on getting sealant into the gap. Then flatten the sealant with your putty knife.
The second pass is to apply more sealant on top of the sealant from the first pass. Again, flatten with a putty knife, only this time make sure there is 1 inch of sealant on both sides of the seam.
Make sure to get the sealant flattened and smooth so that it will be a flat surface to tile over.
Corners
Applying the sealant in the corners is the same process as above. The one difference is that instead of using a flat putty knife to smooth you would use the corner tool instead.
Tub or shower flange
Make sure to apply sealant between the tub and GoBoard panels. In the video, I show my own technique for this which is not required. The important thing is to make sure that gap gets sealed.
Clean up and final steps
I found that the sealant cleans up with denatured alcohol. You can use this around the tub or shower also to clean the GoBoard sealant off.
When you are complete, make sure to check for pinholes and voids.
Once GoBoard tile backer board is installed and the sealant has dried you are then ready to install tile.
For more information, including technical and safety data, please visit GoBoard’s website.
What if I can’t find GoBoard Sealant in my area?
Some people have mentioned that they have found GoBoard Sealant difficult to locate. If you are unable to purchase this sealant GoBoard has an alternate sealant list on their website available to download.
Below is a list of the sealants that were listed at the time of this edit (early 2020). You should always check their website for the most current list.
GoBoard Alternate Sealant list
- DAP 3.0 (model 18360)
- KBRS ShowerSeal Polyurethane Sealant
- Liquid Nails Fuze-It (model LN-2000)
- LOCTITE PL S10 Polyurethane Concrete Crack & Masonry Sealant (model 1618522, 1618521 or 1086693)
- LOCTITE PL S40 Polyurethane Window, Door and Siding Sealant (model 1618516 or 1618182)
- OSI QuadMax Window, Door & Siding Sealant (model 1868684 or 1893977)
- QUIKRETE Polyurethane Non-Sag Sealant (model 866011 or 862017)
- SikaBond Construction Adhesive (model 106403)
- White Lightning Optima White Premium Hybrid Sealant (model W31200010)
- DAP DynaFlex 800 (model 80800
- Rapid Set Sealant (model 196330010)
They mentioned that other sealants may work but to stay away from self-leveling, silicone, and latex-based sealants. More information about caulk vs sealant.
Updates
GoBoard is coming out with new products all the time.
- Sealant is much more available and offers a 10-year warranty
- Same with the screws (which now have Torx heads)
- Seam fabric
- Shower pan wedge system
- Board spacers (see video below)
Great video!! I would like to know how many tubes of sealant did you use in this install? Also, do you know if this sealant is pretty much identical to Kerdifix?
I saw your advice about installing horizontal blocking behind the tub flange. Would you recommend that for an acrylic shower pan flange also? How frequently would you screw the Goboard into that blocking… every few inches? Or every six inches like you do on the studs?
Thanks for demonstrating this product!
I’m glad that you asked this and I meant to address this in the blog post.
I would figure 1 tube per sheet of GoBoard and then 1-2 extra tubes. Additionally, if you have extras that you are doing, such as a recessed shampoo niche or bench, then you’ll want to add an additional tube for those things as well.
The blocking around the perimeter of the tub has more to do with proper framing and building code and isn’t GoBoard specific. But, yes, it should be done around a shower pan also. I don’t believe the board needs to be screwed into the blocking- it’s just for support. However, you could add screws to it if you wish.
As far as similarities of GoBoard sealant to Kerdi-fix, I really can’t say. If you can’t find GoBoard sealant near you then they did OK alternate sealants from before GoBoard sealant existed. I’ll try to find a link to the one that I used to use an update this post later.
edit: I think this is the product here https://www.dap.com/dap-products-ph/premium-polyurethane-construction-adhesive-sealant/
Hi,
Thank you so much for doing this video. I also discovered your blog and it is extremely helpful. I like that you take the time to write eveything out. I did have a question that I wasn’t so clear about: how much space did you leave above the tub between the goboard and tub flange. I think on the center panel you didn’t leave a gap and then for the side panels you did. Is that correct? And if you didn’t leave a gap did you rest it on the lip of the tub so the tiles could rest on the lip or on the tub or even above the tub? Do you mind explaining that? I’m confused on how the board and eventually the tiles should be placed.
Also, do you have an post on how to make sure that your studs are level?
Thanks
There should be 1/8 inch gap between the tub flange and GoBoard and the gap should be filled with sealant.
I don’t currently have a post on flattening walls but I do have one planned for the future. Thanks.
hey tile guy.. I have a situation regarding my polyurethane sealant.. it’s still sticky after a day??? is this normal and is it ok to begin tiling?? thanks for all your insight.
i should also add i’m using Loctite sealant as goboard brand wasn’t yet available at the distributor/retailer.. i am a first timer at bath/tub tiling btw.. :) thanks again for all your comments and info ..
I had this happen once and after a second day the sealant was dry.
I don’t know which specific sealant that you used but if it’s the kind that meets GoBoard’s requirements then it probably just needs an additional day to dry.
After punching up this article ( awesome blog and info BTW! ) I have narrowed down my product search to the GOBOARD product! I really wanted to use something other than the cement boards but there weren’t any options that didn’t break the budget. I just called a local place less than 5 miles away and they told be the price is $16.50/board.. That is less than half the price of the other foam boards on the market.
Lots of good information here, Thank you.
In the second video they seal the joints in the wall installations with sealant and no mesh tape, but on the floor install the joints are sealed with thin-set mortar and mesh tape covered with brush on waterproofing. Schluter seals their board with kerdi tape and unmodified thin set for both walls and floor. Are any of these methods better or worst than the others. I’m working on a barrier free shower floor specifically.
$16.50/sheet is better than I can buy it for. Sounds like it’s working out great!
All three methods work and that’s really all that you are looking to accomplish: that the installation is waterproof.
If all that you want to do is waterproof outside of a curbless shower then I would be completely comfortable with any of the three.
If you are waterproofing inside the shower, specifically the shower floor, I would want the additional protection of mesh tape in the corners. With the Schluter system this if probably unnecessary because they have their own tape.
But the most important thing is just to follow the instructions.
My personal preference is to use sealant and mesh tape in all critical areas. But that is purely my own preference.
Lol… They misquoted me Hard Backer… it’s 28.50 a piece… big difference!
I’m with you. Mesh and sealant. I don’t understand how one can make a watertight seal with thinset.
BTW I just put you on my favorites toolbar. Way more understandable info than any other place I’ve visited. Only down side so far is that I get lost in here.
Some where (can’t find it again) a fellow posted about sloping his sub floor and topping it with fiber backerboard and membrane. He had been advised not to use the backer board with his liner drain. I like the idea of framing the sub with a slope and wounder why He couldn’t just put a go-board floor directly on the subfloor per the recommended procedure. Seal it to go-board walls and he’s done. What am I missing?
$16.50 is a lot of money for Hardibacker. You can buy it at the home improvement stores for a lot less than that.
If you want to frame the slope for your shower then that can be done. If you want to install GoBoard over that then I don’t think that there’s a problem with that. But everything needs to tie into the drain properly.
I don’t know where the exact comment is but I think he had the wrong kind of drain for his waterproofing system. If you want to do as you’ve outlined then you need a drain that accepts a surface bonded waterproofing system. A drain for a typical mud bed system where the waterproofing layer is below the mud bed won’t work in this situation.
Examples of the kinds of linear drains that will work are Kerdi-line, Laticrete Hydroban, and my personal favorite- Noble Freestyle (also called Sioux Chief Streamline). There are also plenty of others including third-party suppliers that don’t supply their own waterproofing system.
I appreciate the comments and that you’ve added this into your favorites. Great choice!
Thanks to your help we have our Goboard installed and will be ready to tile soon! I see that Goboard recommends either nonmodified or modified mortar for installing tile. I know that Schluter recommends nonmodified over Kerdi due to it not needing to dry to cure. This has made me nervous about a nonmodified being unable to dry between the big tile and the waterproof foamboard. Are there any LFT modified mortars that dry ok in this environment, or that don’t need to dry to cure? Thanks for your time!
My personal opinion is that the whole modified vs unmodified thing is overblown. Schluter now has their own modified thinset that they approve for their installations.
Furthermore, if you talk to the manufacturers of the mortars they all want their modified mortars used for porcelain tile. At least one manufacturer goes as far as not warrantying their unmodified mortars for porcelain tile.
There are some mortars that have self-drying technology but they tend to be on the higher end of the price scale.
Thank you, that is interesting! Can you tell me the name of some of the self-drying modifieds, other than Allset? Hopefully some that aren’t rapidset, because we move very slow. So far it looks like I have access to Custom, Mapei, TEC, and Laticrete.
For Custom, I think their Complete Contact mortar advertises a self-drying technology. Laticrete has their new 257 Titanium mortar that has their Hydromatic Cure Chemistry. Not sure about Mapei or Tec. With Ardex, I think you have to get into their x77 & x78 (and other) mortars for self-drying chemistry.
But that doesn’t mean that some of the other mortars don’t have it and it doesn’t mean that other mortars won’t dry. It might just take longer. The chemistry part of mortars is an area that I’m trying to learn more about but a lot of it is proprietary and I will never know.
Hi diy tile guy,
great site. was wondering if you have ever used the 1/4″ goboard for a tiled floor? what are your thoughts or recommendations for tiling a bathroom floor using 1/4″ goboard as the backer with a new 3/4″ plywood subfloor with joist 16″ oc?
Thanks
That should work fine. I haven’t personally used 1/4 inch GoBoard for a floor as it seems most of the floors that I do are heated as I live up North. But it would work fine for most floor tile.
Make sure that you thinset and fasten the board down, stagger the seams, then use mesh tape and thinset on all the seams. These things are standard for all backer boards installed over wood subfloors.
GoBoard is great for heated floors as well b/c it has R-Value! I’m never going back to wasting my time waterproofing cement board or buying expensive other foam boards that are not as good as GoBoard.
Yes, it’s a good insulator if you’re going over concrete and want a thermal break between the slab and heat.
But that isn’t necessary over a wood subfloor
Would you put something like planitop on this to flatten out any unevenness from the studs?
Sorry for the late response. I think if my plan were to apply Planitop to it that I’d rather go the cement board route.
Typically, it’s best to have waterproofing as close to the surface as possible. Coating over the waterproofing kind of defeats that purpose.
Yes, it seemed like an oddball way of doing it but I was curious what could be done if a goboard (or any foam board) wall goes up unevenly other than just using a bigger trowel and thicker layer of mortar. Pull it apart, pad it out, put it back up, and reseal it? Doesn’t sound too hard but kind of expensive if you already sealed the joints and don’t trust the caulk to stick to the old stuff.
I think it’s possible to float over the face of foam board but I don’t think it’s recommended.
Not sure about removing existing glued board and reinstalling. It would probably be ok if the old glue was cut out as much as possible.
found another supplier and price for the go board was $20/sheet and the local supplier honored that with contractor pricing.
That’s a good price for Goboard.
Does J-M make sealing flanges for pipe and mixing valve penetrations like other foam backing board manufacturers? Would you recommend using another manufacturer’s product for the penetrations?
I don’t believe they do but they are always expanding their line. I’ve used Wedi pipe and valve seals with GoBoard in the past.
In flooring applications, GoBoard is for Residential and Light
Commercial use only and should not be used as a shower pan base.
Thank you for this. So I correct my above comment that it shouldn’t be used as a shower floor even if the base is already sloped and it’s a linear drain.
With Goboard JM states “Use a dry set mortar compliant with ANSI A118.1 standard or Polymer modified thin-set mortar compliant with ANSI A118.4 standard.” Given this choice confuses me.
Can i use Custom Building Products FlexBond mortar to set 12 x 12 porcelain tile to Goboard? Wouldn’t the drying time pose an issue with using a modified thin set between these two impervious materials?
I think the modified vs unmodified mortar is an issue that’s been overblown. Even Schluter has their own modified mortar that they ok for their products now. If you’re worried about it then give it a little more time to dry but FlexBond will work well with 12×12 porcelain tile over GoBoard.
Hello,
I am using goboard on our bathroom remodel, and was wondering, if coatings of polyurethane as a top/finish coat is doable??
Just wondering about this due to my use of poly-u on many of my projects and furniture.
Thank you!
Mark Kent
This isn’t something that I could offer anything intelligent as it’s simply outside my field. Your best bet would be to try to find someone at GoBoard that is knowledgeable and can give good feedback.
Hi, I’m wondering if it’s ok to install Goboard over 1/4″ plywood for my shower walls? I need some spacing in order for the Goboard to reach the beginning of the tub lip. Thanks for any info.
Hi. I will be installing sections of tiled GoBoard with screws into wood and metal studs (it’s an interior art installation). I’m familiar with Wedi requiring Wedi washers to prevent screws from moving within the wedi board. I understand that washers are not used with GoBoard.
The sections of tiled GoBoard may weigh 40 to 60lbs. once tiled. Do I need to be concerned that the GoBaord may shift around the screws if I don’t use washers?
Thank you very kindly,
Len
This should be just fine. If anything it would add additional stability which is never a bad thing.
As long as the screws are completely fastened and there’s no wiggle room I don’t see that as being an issue. If you put screws in every 6 inches it shouldn’t matter if the studs are metal or wood.
I don’t know if GoBoard forbids washers. They may just deem them unnecessary. You might try contacting their tech department and asking if they will approve of washers for the installation.
Great! Thank you for the response. I appreciate it!
Hi, & thanks for your tutorial on GoBoard. I’m having trouble finding a concise answer on how to handle GoBoard to drywall transitions. Seems like you seal the seams same as anywhere else on GoBoard, either the caulk sealant, or thinset, mesh tape, and then waterproofing over that? Or am I missing something?
Thanks!
You are correct! If the seam is near the shower glass then it should be sealed with sealant. Otherwise, either sealant or thinset & tape is fine.
KBRS tileable shower pans, niches, and benches work extreamly well with go board for a compleat shower system. It’s the only thing we use for our showers. No fails, no leaks, no call backs. Perfect every time.
“Quality is never an accident “
Great stuff. Is there any reason to seal the mid sections (not the seams themselves) with a water proofer such as RedGard or is that belts and suspenders?
The only thing that needs to be sealed is the seams and penetrations. The foam, itself, is waterproof. So if “midsection” is a seam then- yes it should be sealed. If it’s the middle of a panel then- no- only screws would be sealed.
It is OK to fill the seams and penetrations with thinset mortar and then treat those areas with Redgard. But if it’s already properly filled with sealant then Redgard won’t have any positive effect.
This is a great informational site and the video was well done. I will be transitioning to 1/2″ drywall outside the tub surround area to be tiled. I am fairly handy but this will be my first wall (wet area) tile project. Do I need to make sure that all of my tile ends up on the Goboard or can the bull-nose tile pieces overlap onto my drywall? Also, on the same note, do you have any tips for me if I plan to stop my tile a foot or two short of the ceiling. Do I put Goboard only where I am going to tile and leave the drywall which is already in place? If I do have Goboard where there is no tile is it paintable and texturable? Thank you in advance for any help you can give me.
I’m about to start my first tiling project and have some questions about GoBoard. I’m putting in a new cast iron tub and will be using GoBoard for the walls above the tub. GoBoard seems to be the only foam backer board available in the area I live. Not only that, but none of the supplies carry any of the GoBoard sealant, screws, etc.
1. The plan is to use cement board screws and one of the approved sealants. Do you have experience with any of the approved sealants? Wondering if one is any better than another.
2. I see JM doesn’t have pipe or valve penetration gaskets. Can you use a gasket from another manufacturer? If so, do you use the sealant or a thinset to put it on?
3. JM also doesn’t sell niches. Would you recommend using a niche by another manufacturer such as Kerdi, or just build my own using the GoBoard and sealing the edges with the sealant?Building my own makes me nervous with the amount of joints there will be. I really don’t want any leaks.
TileGuy will probably make the better recommendations but I thought I would share my experience.
1. Alternatives work fine.
Rock-On screws can be used. I’m sure Backer-On as well. As long as they are an alkaline resistant screw which those two are, you are fine substituting them for the JM screws. I could find no difference in the coating between Rockon and Backeron except the color. I chose the Rockon screws because their thread shape looked identical to the JM screws. Initially I bought a box of the JM screws, but my supplier only had 750 count for $35 a box, yikes! Yeah, I returned that. The $7-8 box of Rockon met the purpose just fine. JM’s screw head is slightly larger but its inconsequential. The biggest difference was you need to screw in every 6″ to meet their requirement versus 8″ that the JM screws (now) require. Those pre-marked dots on the GoBoard are spaced every 8″ so adjust accordingly.
Any of those approved urethane sealants will work. Again, JM doesn’t have a magic formula in theirs. But I will say, I did purchase and use the JM GoBoard sealant except at the very end when I needed a little more. Those JM tubes aren’t cheap either. Anyway, so I went shopping at HD for a tube of one of the JM approved urethane sealers. After hunting through so many of the variations. I only found 3-4 that totally matched in name and exact model # within the sea of them at HD. The Henkel, Liquid Nails, and DAP brands were more readily found. I ended up using the DAP 3.0 as unlike some of the others, where they say 100% weatherproof urethane sealer, the DAP says 100% waterproof as well which is what the JM tube says. Btw, the DAP has definitely less odor than the JM and is a little different tactiness when working with it. I don’t think you can go wrong with any of their approved options.
2. You can cut the GoBoard pretty easily,
I had no problem fitting it right around the spout end and the valve rough-in box. (I used the Delta R10000-UNBX which has a plastic sleeve). Initially I thought about using the Schluter gaskets but they don’t want you to use modified thinset on them. I understand they only make up a small area, but still there’s a conflict for me. Besides, if you can measure and cut right, I didn’t see the advantage in using them? Perhaps wedi would work? I dont know, I didn’t need to find out. ;)
3. Build your own niche!
You are going to have leftover GoBoard likely anyway. That $80-100 prefab Schluter or whomever niche is still going to say non-modified thinset (whether you chose to ignore that or not) and then you have the sealant question again. I did considered those niches as well.
Btw, at Menards, they had Prova niches, which look just like a GoBoard type of fiberglass material and they are only $60 when comparing. But when I examined them, their not exactly put together to a strict tolerance. Prepare for some wrestling to get it right in the studs. A couple more knocks on Prova, there were no directions inside, the company had to email them out. When I held it to the light, I could see pinhole light coming through where they “sealed” the edges of the box. The (only) literature inside the box says it comes with a glass shelf, inside was the thick styro-fiber shelf. The company says oh, the glass shelf comes with the ones sold in Canada, for the US market, they sell the glass shelf separately for $24. Really? Does the installation instructions cost extra as well? But at least the US market gets misconception of what’s included. Yeah, no thanks.
Have you taken any of the prefab niches out of it box? Do it, wait for the shock. You’ll go, really? This is it? That’s all? A piece of cardboard?
And then, deal with those required washers and screws Kerdi/Prova, etc want you to use to mount it.
And then more, what about your tiles, do you have to make extra cuts and change your layout, because those prefab niches only come in their sizes, not yours. Its really nice to get a good size niche that meets up well with your tile layout.
‘Nuff said.
Just use your noodle a bit more to think about how it should come together. I even cut my niche hole out of the GoBoard AFTER it was in and I had the bottom row of tile coming up to where I wanted it to be. It made it nice not guessing if my tiles would be off or if I cut the hole right to begin with. Just angle your shelves appropriately for drainage.
4. Have fun. It only hurts until you get in :)
I’m happy to show you some pics if you need some inspiration.
You want the tile to lap onto drywall so that you have only drywall exposed past the tile. However, you want GoBoard to be installed anywhere that will get wet.
So it’s ok to drywall the top of the shower and overlap bullnose onto drywall. Typically, GoBoard would go at least as high as the shower head would be at least as wide as the shower pan or tub.
I’ve used one of the DAP sealants and it was fine. It took a little longer to cure than GoBoard sealant. The QuadMax sealant is supposed to be a good one too.
Using pipe seals from another manufacturer is fine. I would just thinset them on but either method is OK.
Same with the niche. Either way is fine but if you are worried about it then a prefab foam niche is a good way to go.
Good feedback and recommendations. Thank you!
I’m not familiar with the Prova niche but Laticrete, Wedi, and Noble all make niches out of 1/2 inch foam and they are one solid piece- not assembled like the Schluter version is.
I installed the existing tub many years ago and we are updating. I am very intrigued with this product but not entirely sold. I am not concerned about going the most inexpensive route or the easiest route. I want to hear from an expert what the BEST route is.
I am replacing the tub (which is a shower as well) and getting rid of the plastic, three-piece surround. I have removed the drywall to the studs and I am planning my first tiling job. I had to fur out the studs on the first install so the drywall would clear the tub flange. That worked well. Whatever backboard I use under my tile would you suggest I do the same or is there a method I’m not aware of to cover the tub flange?
I would imagine that you have a 60-inch space for a tub so I think the only reason to fir things out would be to drop the backer board down onto the tub? If so, the easiest way to accomplish getting over the flange of the tub is to notch the back of the backer board. Doing this really only works with the foam boards- maybe Hardibacker too.
Otherwise, drywall shims work for a very minimal amount of furring. Or the tried-and-true sistering method.
Additionally, it depends on the tub. The steel tubs have a thin flange that the notching method can work well with. But other tubs can have a thicker flange and the backerboard gets installed on top of them. In that case I use this method for treating the seam.
https://www.diytileguy.com/tile-tub-flange-gap/
Hopefully, I answered your question but I’m not sure if I did, or not.
Wow, that was exactly the information I was looking for. Thank you so much for taking the time to reply and include so much detail! If you have photos of the work you did, I’d love to see them! I’d especially like to see how you handled the tub flange if you did a tub install.
The GoBoard video in this post has good video of what the different steps look like. I seal the flange in this post but also talk about it more extensively in this post.
https://www.diytileguy.com/tile-tub-flange-gap/
Thanks for your comments.
Hi,
After watching your video on installing goboard I am ready to tackle this project. But I’m having a hard time locating the go board product in the Seattle Tacoma area. I can find it at Lowe’s or Home Depot. Any suggestions?
I’ll answer my own questions and hopefully it wii help others. Lowe’s doesn’t have it, you might be able to order it in large quantities. Dunn lumber sells it for about 23.00/sheet.
Dunn Lumber which I highly recommend for supplies anyways. They’re fantastic.
Is tackling these in order so I replied to the previous comment.
But, Yes! I don’t think they carry the sealant so you’ll probably have to use a sealant on their recommended list.
I’m thinking about doing a shower with GoBoard walls and Kerdi ST tray. What would you suggest as the best way to seal that junction between GoBoard and Kerdi, use the sealant (GoBoard way) or do a thinset with waterproof membrane seam (Kerdi way)? Or is it possible to do both, sealant then thinset/membrane over it for even more protection.
Personally, when it comes to waterproofing, I trust sealant more than I do thinset but doing both would be the best approach. Even with sealant I always use some sort of fiber or mesh reinforcement on that junction.
On another matter what’s your opinion on possible water absorption, I read somewhere polyiso foam can absorb water more so than the extruded polystyrene boards, yet Goboard says their foam itself is waterproof. Have you heard anything regarding this?
From compeitiors, I do hear some of these claims. What I know is that I built a box and filled it up with water and it held water for several weeks. I kept a piece of GoBoard submersed in this water and it always floated right back up to the top.
I’ve also seen the GoBoard people with their fish tank that they haul around to the conventions which is built completely out of GoBoard with a glass front.
There may be something to the claim if applying water with extreme pressure, I don’t know, but these types of products just have to work for showers. You can go to the GoBoard website and see the data sheets for the different listings. They’ve passed the tests and have the proper approvals.
what type of thinset is recommended for tiling over the goboard?
This is a good question and I didn’t see this addressed on any of GoBoard’s literature. Personally, I have always used premium modified mortars and wouldn’t hesitate to do so again.
But if you want the official word you’ll have to contact the people at GoBoard with this question.
Hi Patrick,
I will add to Luke’s comment and say thank you for your time and effort on that post. It helped tremendously.
A follow-up question if I may…
For your shower niche, after you cut your GoBoard, did you then install any additional framing for the niche ? I am specifically wondering about a bottom piece to support the niche. If you installed it after you cut out the GoBoard, how did you attach it to the existing framing ? How did you ensure that it was level ?
I have been going over in my head how to install framing “after the fact” so to speak.
Thank you in advance !
I’m not Patrick but hopefully he will reply. :-)
But I just want to say that I have a post on building niches that can be found here.
https://www.diytileguy.com/custom-shower-niche/
Hi Jim and thank you for your prompt reply.
I did not previously see your other posts. Thanks for pointing me in that direction.
After reading these, I have a better idea of what to do. Thank you for all of your extremely helpful content !
Hi Jim,
Your posts are answering a great many questions I have had about this process (installing pre-formed niche). Thank you !
Quick question: Are any of the pre-formed niches pre-sloped for water drainage ? If not, then I assume that, when I install the blocking, the bottom 2 x 4 would need to be at a slight angle ?
That’s a good question and it’s been a while since I’ve used one and I don’t remember which, if any, have a slope on the bottom. However, if they aren’t sloped then pitching the bottom 2×4 won’t do you any good with a preformed niche. You won’t be able to bend the bottom of it.
I suppose you could shave, or sand, the bottom of one so that it slopes? Probably a good idea to check with the manufacturer prior to doing so to see what they think.
Oh yeah, good point. More research is needed.
Another question if I may. I have seen waterproffing videos that use thinset (like your part 2 video) and other that use liquid membrane with some sort of fabric.
The membrane seems like it would be my preference. Easier to apply ( paintbrush instead of trowel ), etc. etc.
Are there membrane products that are more compatible with GoBoard ? Or are they all about the same ?
GoBoard is waterproof so there’s no need for an additional membrane. Just make sure you seal the seams and penetrations Luke the instructions say.
Sounds good.
Many thanks once again Jim.
Hello DIY Tile Guy,
I found your video on YouTube while searching for some answers. I’m remodeling a bathroom that previously had a alcove fiberglass shower in it. I want to replace the old shower with a new one using an acrylic shower base and tiles walls. I’ve been confused in trying to figure out the best method to make a waterproof joint between the walls and shower base flange. I’ve read some places that the tile backer board needs to be brought down to the top of the flange with an 1/8” gap. Other places talk about bringing the backer board down and over the top of the flange. In this video, I see you kept the backer board 1/8” above the tub flange, and I assume that applies to shower bases as well.
Is the standard recommended practice?
If I bring the backer board down to the top of the shower base flange and leave a 1/8” gap, should the face of the backer board be flush with the face of the shower base flange? In my shower alcove, I have a 36” square shower base that fits between the wall studs snug, with not much gap. I don’t think I can make the face of any 1/2” thick backer board flush with the shower base flange. Is this okay? This means my bottom row of tile may not be supported by a backer board.
To waterproof the gap as mentioned above, can I still use fiber mesh tape and sealant as you did, even if my backer board is not flush with the shower base flange?
In some places I read that it is ideal to have the tile hang over the edge of backer board and in front of the flange, as in this photo.
https://www.familyhandyman.com/wp-content/uploads/2017/06/FH09OCT_BACBOA_01-2-1.jpg
Thoughts on this method? Can I successfully do this with the Go Board? Would you still use mesh tape and sealant to waterproof the 1/8” gap?
If I do have tile hanging over the shower base flange in this manner, what do I do when I install the grout bewteeen the tile gaps where the backer board is nonexistent? Or should
I avoid trying this altogether?
If I cannot make my tile backer board face flush with the flange of my shower base, is there an alternative method I can consider trying?
I’m a first time diy tiler, so if I have a lot of questions I apologize and appreciate any guidance you can share with me. Thanks!
This post covers some of the questions:
https://www.diytileguy.com/tile-tub-flange-gap/
You have to work with the flange that you have. If it’s thin, then you can keep the board above it or notch the board of you are using foam backer board.
If it’s a thicker flange, then you would keep the board above. The backer board has to be flush, or out past, the flange.
GoBoard recommends a 1/8 inch gap between the flange and GoBoard.
Hello DYI Tile Guy,
You’ve already been a big help to me with the videos and Q & A’s. I have installed the GoBoard according to your instructional video. I did not have the GoBoard sealant available to me so I went to the GoBoard Website and found a list of alternate sealants which are approved by them. I was able to find Quad Max OSI Window, Door and Siding Sealant. It is done curing and I have my tub surround ready for tile.
This leads to my question/concern:
At the seams the dry sealant feels like rubber and it leaves me wondering if the thinset will adhere to it? My tile measures 10 X 16. This is my first tile project and want to make sure the thinset will work over the sealant to hold the tiles. Is there a construction glue that can be used in lieu of mortar.
If I could please get your expertise concerning this question I don’t believe I will have any other questions and I’m on my way to my first successful DYI tile project.
Thank you again for all your help
It’ll be fine. I’ve asked multiple manufacturer’s about this before and none of them seem to think it’s an issue.
Hi Jim,
I have installed the GoBoard on TOP of the tub flange…with a 1/8 inch gap of course.
The GoBoard, however, is not flush with the flange. The flange is thin and is butted up against the studs.
As a result the GoBoard ‘juts out’ past the flange so to speak. So there is a bit of a recess.
Do I just inject sealant into the 1/8 inch gap and then ensure that the bottom surface of the GoBoard is covered with sealant ?
thank you for all of the advice and guidance.
That’s what I would do. In the video, I had this exact same situation on two out of three sides. Just seal it the best that you can.
I’m installing goboard as a thermal break on my concrete slab floor and I’m putting electric floor heat cables in. Can the floor heat be installed right on top of goboard before thinsetting and tiling?
Yes, you can install the cables then install thinset + tile. Personally, I like to thinset over the cables and let it dry to encase them prior to tiling.
Can goboard be used outside for stone veneer on a house instead of a mortar bed?
This is a good question and I don’t know the answer to it. Exterior applications aren’t listed in the Limitations section but they aren’t listed in the Uses section either.
You best bet would be to call their technical assistance line and see what they say.
Can I use glass tile with GoBoard? The other brand states that it doesn’t work that well due to the mortar that you need to use. Thanks for any info!
GoBoard is fine with modified mortars being used so that’s not an issue with glass tile. But check with the glass tile manufacturer. Some glass isn’t supposed to go over a surface bonded waterproofing membrane which is what foam boards, like GoBoard, has (is?)
Can you use electric floor heating mats over GoBoard?
Yes. GoBoard is a decent insulator.
I can’t find goboard for sale anywhere online. I live in Mississippi and did manage to find one place in Brooklyn. Shipping was going to cost $150. If anyone knows where I can purchase this product….please let me know! We need 8 sheets of 1/2″ and 1 sheet of 1/4″. The 1/4″ works well with shower niches within 4″ stud walls….offers a little more depth.
I thought that you could order in GoBoard through Lowes or Menards? Not sure if they charge shipping though.
Hello,
I just came across Go Board from another contractor friend of mine. I originally thought the boards were foam insulation, haha. Anyway, I have a 200 square foot kitchen floor tile job coming up in the fall and thought about using it. I originally planned for 1/4″ backer board as the subfloor is thick enough already and don’t want to build it up too much. Just wondering if you think using the Go Board I should bump it up to 1/2″.
Also, I always lay my backer board in thinset and screw it down. Do you do the same with Go Board or do you use a different adhesive?
Thanks for a great site. Just came upon it in my search for info on Go Board.
From a structural perspective, there is absolutely no difference between 1/4 and 1/2 inch GoBoard over a floor. It’s the same for any underlayment- it never counts towards the structure. If you want to enhance the floor you need to do it with plywood or other means. So whichever thickness you think will suit your floor is the one to choose. Typically, it’s the 1/4 inch.
And, yes, it gets installed with thinset mortar and fastened with the approved screws, nails, or staples. I believe the seams should be staggared, as well. These are just some of the nuances that can be found in the GoBoard installation instructions.
Thanks for the reply. I appreciate it.
John
Think read somewhere but can’t remember or find.. If putting goboard & tile up to ceiling meeting the ceiling drywall how do you seal junction? Paintable sealant/caulk or ??? can’t see the drywall tape working on the goboard or thinset on the drywall but maybe it does. I’m almost leaning go back to not tiling to ceiling but that has other issues. Is there a recommended method(
I think the best way is to use mesh tape and mud the ceiling part of it with drywall mud and use thinset for the tile wall. However, if you didn’t want to go to all of that work then painters caulk would probably be OK also.
JM now has goboard wedges to make a sloped shower pan and according to their literature “GoBoard Wedge and Curb are manufactured using the same process and raw materials as GoBoard Tile Backer so installers can expect the same level of performance”
So I appears I can use goboard as a pan.
If Zach is still around, I would be interested to know what he based his advice on. Thanks
I’m not sure if Zach will pop in, or not, but I think the application that he is referring to is using GoBoard backer board panels over an already framed slope for a shower floor.
However, GoBoard wedges being used as a shower floor is exactly what they are designed for.
Yes, I am refering to using 1/2 goboard on a framed, sloped subfloor. I don’t understand how that is any different than sloped goboard on a level subfloor. The materials are identical. The finished tiling surface is the same. And the process is the same. It’s a single slope so one piece of goboard will cover with out the seams associated with the wedge panels.I’ve been loking for a way to ask JM but only find corporate office contacts. Nothing specific for goboard questions.
Thanks for replying, That’s a courtesy I haven’t had from some other boards I’ve queried.
I’m afraid I don’t know how much help I can be with the new wedge system. I’ve never seen it and don’t know anything about it other than what I see on their website. The wedges should be thicker than a building panel and may have a specific way to tie into the drain. It doesn’t look like they get fastened to the floor- only mortar.
I’ll have to ask my local rep about this product but I don’t plan on seeing him until the end of the month.
It would be worth the wait if I could get a JM contact. Fell free to pass my email on if the opportunity comes.
I did notice in JM’s installation video for the wedges that they have adopted your method of leaving 1/8 ” gaps and filling with PU after.:-)
good work… as for the sealant between boards, I had 2 questions:
1 – you say that you should have an inch coverage of sealant on both sides of the seam… OK, I’ll buy that since I generally “over” do things to be on the safe side, but I would like to know “why”… why must there be a 1″ coverage on each side?
2 – I noticed you used mesh around the tub flange, but not on the seam higher up on the wall… why? My thinking is that higher up on the wall when someone is standing to take a shower, they will bump into the wall and most horizontal seams don’t have structural wood horizontally behind for bracing (only vertical studs at 16” OC).
I cant find this product near me any idea where I can get. Located north of chicago
Mesh tape isn’t necessary but I thought it would be useful around the tub. You can certainly use it over other seams, if you like.
The 2- inch coverage of the seams is a manufacturer requirement and is common amongst other brands, as well. I’m not sure what all the reasons are for that requirement.
If you have a Menards, I think they carry it.
Does anyone have a good source for the blue GoBoard fasteners?
https://www.jm.com/content/dam/jm/global/en/tile-backer-boards/GB-107%20GoBoard%20Fasteners.pdf
Thanks!
Personally, I’m not aware of an outlet that stocks them in my area. Certainly, you could order them in but maybe someone will have some info.
Hi! I left you some questions and can’t find them and not sure if you’ve answered them already? Have you used Jet board? I live in a manufactured home and am considering it for a backsplash over the thin walls. Also do you think I need to waterproof area behind sink if I’m using specktalock epoxy? Thank you.
Hi Donna, you are up near the top of the comments in this post:
https://www.diytileguy.com/thinset-buyers-guide-part-1/
Below is a copy of one of the two comments that I made over there:
I’ve a question on how to proceed with a tile project that we have going. Our tile person had me install go board. I’m a plumbing contractor in business for over 26 years, so I’m very familiar with products and I’m but for details and proper install practices. I watched your video prior to installing our board product and questioned our tile several times in regards to sealing the joints. I told him about your video and the caulking of seams. He insisted on us letting him seal, but he also insisted on using thinset mortar and taping the joints then applying RedGuard water proofing. Unfortunately our tile man had a freak accident leading to his death. Sad situation to say the least as he was an awesome person. However we are now left trying to figure out what I need to do with the walls that were never sealed at the joints yet. I’m really not comfortable with thinset and tape method. In your video you used 1/8” spacers for proper gap. We followed our tile mans direction and butt the joints tight. I could probably razor cut an 1/8” gap where needed. I did leave this gap along tub deck area and along skirt front that goes to floor. I’m very curious as to what sealant to use as the place we purchased it from does not sell the goboard sealant. Where can we buy it? Secondly would you recommend just proceeding with his method? And what are your thoughts on applying the RedGuard water proofing?
Thanks, Sean
The GoBoard instructions allow for the method that your tile installer wanted to use. When thinset and taping the seams they say to have a maximum 1/8 inch gap. When the sealant method is used they say a minimum 1/8 inch gap. Is butted together too tight if you want to tape and mud the seams? I can’t make that call.
So you’ll have to choose which method you want to use. For sealant, you’ll have to open the seams up a little bit. You may even do this with the thinset/tape/liquid waterproofing method.
GoBoard’s website has a list of alternative sealants along with liquid waterproofing products that they recommend for their board.
Sorry to hear about your tile installer and I wish you the best with your project moving forward.
Great post I had a question about goboard . I am installing onyx solid wall shower panels that are waterproof , Wanted to know if goboard would work with onyx shower panels ? Also they told me to primer goboard panels to keep bleed through from happening can you use latex primer on goboard and will it stick ? Panels are installed with silicone circles on back of panels every six inches . P,s> You should do a post on using goboardv on Onyx panels . Thanks
I hope your shower panel isn’t real onyx as that stuff is not maintenance friendly. However, I don’t see a problem with using GoBoard with the panels but it’s more of a question for the panel manufacturer. They should have instructions for how they want the areas waterproofed for their product.
You can use latex waterproofing for GoBoard so latex primer might work just fine?
What material did you use on the face of the studs prior to attaching the goboard?
Probably, some drywall shims. (affiliate link)
It may seem like an odd question but I’m new to the DYI scene. Is KBRS Kerdi?
No. KBRS is its own company. Schluter is the company that makes Kerdi, amongst other products.
There are no wrong questions.
Hi, we just ripped out 3 year old tile and cement board and replaced with GoBoard, easy and great to use! However after tiling, adhering with light mapai tile adhesive (which we have used before with cement board with no issues) I have a strong fishy odour in the bathroom which we cannot get rid of. Have you heard of this before? The house is only 3 years old and we had no issues with smell before we started, we just didn’t like the original tile. The smell is unbearable!
I’ve never had a smell last after tiling that was unbearable. And I’m not just including GoBoard installations in that but with any installation. However, I don’t claim to be the most sensitive either.
It sounds unusual to me and if you do suspect that it is GoBoard, the product, I think you’d have to contact them and see if they will send someone out to investigate.
I installed GoBoard with the wrong side facing out on one section of my tub surround — so the side with branding isn’t visible from inside the tub. Is it waterproof all the way through, or should I take this section down and redo? Thanks!
It’s fine
Any tips on installing goboard around the toilet on terms of placement and sealing? Our flange is raised up off the subfloor because it’s was installed over the old tile. What should the flange be flush with?
The flange should sit on top of the tile. In a perfect world, anyway.
Just make sure that GoBoard is installed with thinset and fasteners both when installing over a floor
What is recommended to seal the exposed edge of GoBoard? I am using a circular piece for a glass decorative mosaic cover for a fire pit. I used a recommended substitute for GoBoard sealant, which was not available in my area (Liquid Nails Fuze It LN-2000) to attach it to a piece of sealed MDO. I’m unsure of whether to continue with the Fuze It or if something exists that might work better. It will be outdoors in all but the dead of winter if that makes a difference. Thanks for any guidance, I’m learning a lot reading here.
I’m installing goboard with a KBRS tile-basin shower pan. The KBRS installation requires adding 1/4″ furring strips to the stud walls and then screwing the goboard to the walls. However, at the top of the shower where the goboard meets the drywall, the transition is not flush. The goboard sits 1/4″ higher than the drywall, so I’m wondering if you have any advice or suggestion on how to get around this problem.
I don’t really understand the question but GoBoard and heat/fire don’t mix well together. You don’t want GoBoard near an open flame or high heat. If this is the case in your situation, I would replace GoBoard with a cementitious backer board.
Additionally, if it’s not a waterproof situation then you don’t need the sealant. You can simply use mesh tape and thinset mortar. This is probably a better situation to adhere glass mosaic tile to. So maybe that’s how you can treat the end of the panel? Hopefully, that answers your question but please ask again if I’m not understanding your situation.
Thanks for answering, and I’m sorry I wasn’t more specific, the cover will only be used when the fire pit is not in use. It will be out in the sun/rain, but otherwise will not be subject to extreme heat. I did plan on using thinset for the mosaic but was going to prime then paint the edges and reverse.
OK. Sounds like a good plan then.
Linda, You’ve probably already completed your project but for the future I would HIGHLY suggest going with a 3M product for sealing the edges of the GoBoard. I’ve been using it since it came out and have found the 3M 540 (they use a 540 in the GoBoard installation video) is your best bet for interior and some exterior applications (vertical surfaces) For the cover you’ve described I’d actually go with the 3M 5200 Marine Adhesive. You can find both at Zoro.com or zoro’s ebay store. The 540 is $7.32/cartridge + shipping. The 5200 you can also find on Amazon for $15 includes delivery. I would also suggest the first method of installation for any application where you’re butting pieces together (ie a shower) This way all you need is a cheap plastic 2″ putty knife to smooth all your seams and screw indentations. Toss it away when you’re done. If you use the sealants above you’ll understand why. I’ve done a few stone tile ledgers in northern Wisconsin with GoBoard as a backer and it’s crucial to make sure the seams are sealed. If water gets in there during a winter thaw and it freezes again, it will pop the stone right off the wall.
You’re best bet IMO is to pull the drywall and run the GoBoard all the way to the ceiling. If that’s not an option. You have several alternatives. 1) Assuming you’re going to tile the shower. You can get a tile trim to go around the top where the GoBoard meets the drywall. This trim will depend on the thickness of the tile you’re putting up.
2) They make 1/4″ drywall. Screw it right over the existing drywall, between the GoBoard and the ceiling. Then tape and mud the wall/ceiling joint 3) They make 1/4″ GoBoard, Add sealant to the edges and SCREW IT RIGHT OVER THE DRYWALL, then you’re back to the original solution of tiling all the way to the ceiling without having to take the existing drywall down. FYI When I’m doing a new walls for a shower/bath I notch out the bottom of the studs 1/4″ up to where the flange for the base is going to sit. That way instead of adding 1/4″ furring strips and running into this problem, you end up with a continuous flat surface. Then I run GoBoard up to where I need it (or the ceiling) and then drywall above that. So basically add 1/4″ to 98% of the stud OR notch out 2% of it a 1/4″ If you can do it, the latter makes more sense.
I apologize as it looks like I missed this one. But I agree with everything that Tony said above. You’ve probably moved on with the project but this may help someone out in the future.
Hey Mr.Tile guy, you really set the bar at the correct level – hopefully other wannabes will follow your lead. Your experience clearly shows you know what you’re talking about and I’m grateful you are willing to assist folks and honest to say you don’t know about some unpopular issues. That’s credibility! The reason IMO there are so many DIY folks nowadays is directly related to the lack of quality at excessive prices. There’s nothing worse than an arrogant overpriced contractor that performs sloppy work and still expects call backs and follow on work.
Ok off my soapbox. I have read through all of your content and all of my questions have been answered!!!!! NICE! However, I wanted to share my experience with GoBoard hopefully to help others.
I purchased GoBoard from a local Fairfax Va. plumbing shop. I purchased the Full sheet 4’ x 8’ x 1/2” GoBoard ($40/sheet) to avoid additional Shower wall seams. I only have two corner seams Now but sealed and waterproofed those. I also purchased a KBRS custom 4’ x 4’ shower pan with 5” water guard ( built onto shower pan by KBRS as standard design) and linear drain.
I like the GoBoard And working with their tech support, they were very accommodating with my questions. After working with it, I now know why this large sheet is not popular. Imagine trying to maneuver full sheets of plywood through your home multiple times, it ain’t easy.
Anyway, thank you for proving so much valuable information.
Frank
Thanks for the feedback! I’ve got a shower right now that I’m using GoBoard on and wish my local supplier stocked 4×8 sheets. I understand it’s not the easiest thing to get them into the house but it’s nice not to have all of the waste either.
I need to re-tile my shower walls, and seems like this is a great option and available at my local Lowes. The don’t carry the GoBoard sealant or fastners and I couldn’t find them online (JM – can’t imagine it being that difficult to sell these items on Amazon!).
Can I use kerdi washer/screws as fastners? I don’t want to use cement board screws and risk going too far in/out. Alternative sealants seem to be available, so no issues there.
You can probably use the washers as long as the sink in just a little bit so that you can put sealer over them. If the washers don’t recess just a bit then I’d switch back over to cement board screws every 6-inches and just be careful with how far you drive them in
Can goboard be used in place of sheetrock in a bathroom ( not the shower walls) and then painted? Also did you say to use mesh tape between goboard in the tub surround and the drywall?
It might be able to but I don’t know why you would want to. I’d rather see you go with Denshield if you want a tile backer that won’t be used in the shower. It is gypsum based and will still have some fire protection qualities, unlike GoBoard.
Thank you for really helpful and valuable comments on GoBoard.
We are redoing two baths in our home and plan to use GoBoard above an alcove tub and above a cast iron shower pan with an adjoining bench.
We are looking at large format porcelain tile 12×24 inches with narrow grout lines.
Is there a suggested overlap of the tile onto the Sheetrock? Thinking 1-2 inches on the wall, with stud behind joint.
For bench seat, ok to put GoBoard on 3/4 inch plywood and 2×4 frame with 1/4 inch per foot slope?
We like the idea of Custom GoBoard shower niche between stud walls- can we set the back and sides on niche floor that has slight slope on top of 2×4 support?
Anything else we need to consider with the tile install?
Thank you!
From a water management point-of-view, I think it’s nice to have GoBoard extend past the shower curb, or tub, about 1-2 inches. Then, you want to have the tile cover the GoBoard and the transition to drywall. Normally, this requires about 1-inch minimum. As far as I know, there is no rule on how far to overlap.
Yes, to everything on the bench question
Not sure I understand the niche question but I think so. You want 2×4 support and the bottom to slope. I do have this post on making a custom niche. Hopefully, it’s helpful. https://www.diytileguy.com/custom-shower-niche/
Just to note: another option on these shower niche’s are well – made stainless steel ones. There are quite a few out there and some come with different finishes. They can be a bit pricey, but there is the benefit that you don’t have to tile them! As well if you think about it, like the one below, buying a pre fab one is more than half the cost already, and you still have to tile it. I’m going to try the one below in my bathroom.
https://www.lowes.com/pd/ALFI-brand-ALFI-brand-24-x-12-Brushed-Stainless-Steel-Horizontal-Single-Shelf-Bath-Shower-Niche/1000955658?cm_mmc=shp-_-c-_-prd-_-kab-_-google-_-pla-_-130-_-sosbathing-_-1000955658-_-0&placeholder=null&gclid=CjwKCAiA-_L9BRBQEiwA-bm5fr271xbL_xPEBJsxK5xlOlZfEvg9uAdatA5CRANpRPWxoSd-_D9m7RoCuUIQAvD_BwE&gclsrc=aw.ds
Is modified thinset the only thing needed for attaching 1/2″ thick GoBoard (1/2 thick) to a concrete slab? Can a 2nd layer of 1/2″ thick GoBoard be added for additional R value or is this a bad idea for under tile? I will be using an uncoupling mat for heat cable. 1/2″ thick GoBoard is the thickest available in my area. I don’t want to waste any more money heating the slab than I have too!
Thanks to All,
Kerry
Thanks for this information
The slab needs to be able to accept a bond with the thinset but, yes, you just need to thinset it down and make sure that the board stays bonded until it’s dry. You might drip a little water on different areas of the concrete and see if the water beads soak in. If not, or if it takes several seconds, it’ll need some prep work to be able to bond with the mortar. I talk a little about this process in my self-leveling post:
https://www.diytileguy.com/self-leveling-underlayment/
Doubling up GoBoard is something that I’ve never been asked and I don’t know the answer. You’ll probably have to check with their tech department and I would love it if you come back let us know what they say.
Thanks for the guidance. I had emailed Johns Manville the question before, but never got a reply. After your reply, I tried calling there main number and they put me in touch with their technical support guy on GoBoard. I got his voice mail and to my surprise I received a return call within the hour. He was definitely very knowledgeable on GoBoard and very helpful. He told me there were no issues at all with installing two layers of GoBoard over a concrete slab. He did mention to be sure to stagger the joint, which I would have done anyways. Since I like to go overboard on things, I asked if I could do three layers and he said that would also work! A big thumbs up to Johns Manville for providing good phone support, but not so much on email support!
I do need to figure out the floor prep for the GoBoard, so now I’m moving on to your leveling guide. Thank you for the guidance!
Last spring I purchased and installed a one piece porcelain 12 x 12 niche from a source on the internet. It turned out great. Just needed to assure that the single unit interfaced well with the tile surrounding. No concerns about ramps, piece fits, grout lines or leakes. Wedi was used on the walls and cut out to place the unit.
Good to hear! Thanks for the follow-up.
Thanks for the feedback. That is a nice and simple way to make a niche.
Follow Up Questions for installation…. Does a 1/4 x 1/4 trowel usually work okay for applying the thinset for the GoBoard attachment? Is there anything I need to do to make sure the GoBoard gets embedded good enough into the thinset such as some type of weighted roller or putting some weight on it for a certain amount of time?
Thanks!
Another question. If my floor is level and passes the water test, can i go right over the concrete with the thinset?
That trowel size is perfect. The only thing that you need to do is make the mortar a little wetter than normal. So, definitely be on the high end of the water requirements that is listed on the bag. Run all of your trowel notches the same direction then walk on the board once you get it embedded in the mortar. Start from the middle and work out. Then fasten it down.
I don’t think you’ll need a roller to do it. Cover your mortar right away and you’ll be fine.
I didn’t realize this was over concrete in my last response. You’re probably going to have to weight down the corners and edges to make sure they stay down until it’s dried.
And you’ll want to take more precautions to make sure the board is fully embedded. A roller wouldn’t be a bad idea. Still start in the middle and run your trowel notches the short way across the board. Watch the Trowel and Error video in this post. They do it with tile but it’s the same concept with backer board.
And, yes, you can go right over the concrete.
Thanks very much! Your guidance is making me much more comfortable knowing that I’m doing this correctly, since I don’t know what I’m doing! I have picked out Laticrete 257 Titanium thinset for embedding the GoBoard Into. The 257 Titanium exceeds the ANSI A118.4 specification, which is the specification required for the GoBoard. I would like to make sure this would be okay to use, since it’s a lightweight thinset. Is there anything better that I could use for this application?
That should work just fine
Hello, thank you very much for all the information here, very useful. This question might have been covered somewhere: how do you make a transition from goboard to drywall? In our case we have to make a transition both, on the sides as well as on the top because our tiles go only about to the shower head and not all the way to the ceiling. Our contractor plans to just use a mesh tape and a joint compound. On the top we will have the last row of tiles + bullnose sitting on a drywall (covering goboard/drywall transition area). Not sure if tiling on top of a joint compound is a good idea. Will tiles stick to it? I have read somewhere that it could be OK if joint compound is primed prior to tiling…
Thank you in advance for your advice.
If the seam is going to be covered with tile, which it should be, then you want mesh tape and mortar on that seam, not drywall compound. If the contractor has already moved forward with drywall compound then it needs to have a primer applied over it before you can tile over it.
Thanks for your reply!
I watched your video one more time and noticed that at 21:30 you are closing the gap between the goboard and drywall with sealant. Just to clarify: do you later lay a mesh tape and thinset on top of it to reinforce the seam or just tile over the original sealant?
One more question: on the top seam between the goboard and drywall we have a bit of a mismatch between the two boards because our drywall is bowed inwards in the center. What would be the best way to flatten the drywall and cover the mismatch? Mesh tape + thinset and then extend thinset beyond the seam to level the drywall for tiles?
Thank you!
To the first question, yes, I do, but it’s not required. If you are using the sealant then mesh tape isn’t necessary. I like to add mesh tape anyways but it’s not a must.
As to the second question, I think your solution is probably the most practical one. The mortar isn’t technically supposed to be used in that way but that’s probably what I would do in your situation.
Two questions: first I installed the go board for a shower, fiberglass tub. I sealed all the spaces with the sealant, let dry 24hrs. Came back and seams had all sucked in, sealed but a visible crevice. So I decided to use modified sunset with fiber mesh tape. Now letting it dry. It’s all level, waiting 3 days to tile. This is ok right, even though overkill? Also no red waterproof needed right? 2. Installing 10×14 ceramic tile. Should I use modified or unmodified thinset to apply the tile. Some say the modified won’t dry due to the waterproof tile and go board. What should I use? Thank you so much!
Nothing wrong with doing what you are doing. No additional waterproofing needed as long as the sealant didn’t have any holes in it. I would use a modified mortar. If you’re concerned about drying then you might give it an extra day.
Great video, and really helpful blog!
Do you foresee any issues by adding Kerdi Band around the edges for extra protection after adding the sealant, I know this is probably more than necessary, but just want to make sure everything is watertight.
Thanks!
Kerdi band is a good way of doing it. I’d be more inclined to use it without the sealant and just thinset the banding on.
JM responded to this question in a comments section of a YouTube video, and they said that it met ANSI blah blah blah standards testing rated at such and such. Basically, it will stick. My gut says I would not want very small tile over a seam. I would want thinset to adhere directly to the unsealed goboard surface.
From their PMG-1439 report – “Water vapor permanence value of less than 1 perms, capability to hold 24″ of hydrostatic pressure for at least 48 hours, ability to achieve greater than 50 psi shear bond strengths.”
Thank you for the comments and the references. That kind of information is much appreciated!
Hi Graset video and instructions. What are the grey strips on top of your studs? you can see on the picture where you are showing the red plastic spacer. what are they for.
THank you!!
Anthony
The grey strips are drywall shims that I put on to flatten the inconsistencies in the studs before putting the backer board up. This is a good practice and you can find these in the drywall section of your home improvement store.
The spacer was to keep 1/8 inch spacing between GoBoard panels which is required for the sealant when the sealant is applied after the board is installed.
Hi Tile Guy, I’m installing goboard, sealing the seams with goboard sealant. Is there any issue with going overtop of that with Hydroban and fabric waterprooding mesh tape at the critical joints for extra insurance? Hydroban instructions say the surface should be clean and free of residues, but the goboard instructions say to spread the sealant 1″ on either side of the seam.
Regardless, I will be applying hydroban to the laticrete 3701 mortar bed.
Thank you in advance for your advice.
If you seal the seams with sealant then I would definitely not go over them with additional waterproofing like Hydroban. If you want, you could still use the mesh tape on the seams. I do this with all of my installs.
I would advise you to use reinforcing tape around the critical shower pan seam. Hydroban has a couple of different options that they recommend but even using the mesh tape in the inside corners would be beneficial.
Yes, I was planning to use Laticrete 6” waterproofing fabric with hydroban around the shower pan, though this may cover some screw heads covered with sealant and a few inches of sealed seams up the walls. Is this OK?
When you say I could still use mesh tape for the inside corners, what would I use to embed it, if not hydroban?
Thank you for the response and clarification.
The 6-inch waterproofing tape would be a good product to use and it’s not a big deal if it covers some of the screwheads with sealant. If you know that the screwheads will be covered with the tape then you might opt to not use the sealant on those.
When I embed mesh tape in the seams I do it with the sealant. You do have to be careful that the tape doesn’t block the sealant from getting in the seam. Usually, what I do is seal in-between the panels first, then tape, then a second pass with sealant to make sure it covers one inch on each side. If you cover the tape with sealant then that is your 2-inch sealed seam.
Very good, I understand now.
You are a great resource and I thank you for your dedication to answering all questions.
Not a bath/shower/floor question but does relate to backers & tile but for a kitchen counter. I see goboard instructs to use 1/2″ embedded in mortar over 3/4 plywood. Instructions state to mesh tape/mortar but to also use liquid waterproofing over that for the seams. I have Durock foam board waterproofing tape. Could that be utilized instead with mortar & thus not need the liquid waterproofing? This tile counter is intended to be temporary until build one with walnut from my property. Would sure like to be able to re-use the plywood by ripping the goboard & tile off & attach the plank top. Is is absolutely necessary to embed the goboard in mortar–might there be another acceptable method attach the goboard to the plywood-not concerned about warranties? Everything is perfectly level. I am applying 12×24″ industrial strength porcelain tile that acquired very inexpensively from local factory outlet.
If the counter is temporary then, no, you don’t need to embed GoBoard into mortar. It’d probably be better not to if you are going to remove it. And you can use the waterproof tape but, again, if it’s temporary you don’t even have to do that.
steam shower question here. I was planning on using go board as I have a surplus but understand I need a vapor barrier. I contacted the manufacturer but have not heard back. Next step is to call but I thought I would see if you knew of any products to use as a vapor barrier on the outside or whether poly barrier behind would suffice.
(either first install a manufacturer approved vapor barrier directly to the wall studs and ceiling framing behind GoBoard per the manufacturer’s instructions or install a manufacturer approved vapor barrier or waterproof membrane over the external surface of GoBoard)
Many thanks
It seems to me that you would need to install a vapor barrier over the studs. 6-mil plastic for example. I’m pretty sure they don’t have anything that goes on afterward. However, they do have a new board out and that may be worth looking into to see if it already meets the vapor permeability requirements.
I have water-damaged asbestos tile flooring in the bathroom (used to be covered with thin carpeting prior to the freak flood from a higher level). The flooding destroyed the room below as well, since it is attic-plank-type flooring below the asbestos. What would be the best way to completely waterproof the bathroom (including the entire floor)?
It sounds like you are probably in an older home that may not be built like more modern homes. So, more information would be needed as the question is just too vague with so little information. I do recommend looking at this site if you think you may have asbestos in your home: https://www.epa.gov/asbestos/learn-about-asbestos
Home DIY installer here. After watching hundreds of hours of how-to tiling, I feel very confident I can do the work. However, after I came across GoBoard while shopping for Hardiebacker, I had to rethink the tiling plan, but your site provided the most information and I’m now on board with it.
I’m pretty much on track with all the steps, but I have a few questions:
—you mentioned two sealant passes. One initially to fill the 1/8″ gap, then the 2nd to add an additional layer. Do I wait for the first pass to dry before applying the the 2nd? I want to use tape as a peace of mind, but I don’t want to apply that 2nd pass if it would disturb the gap sealant.
—I really like the idea you mentioned about notching the GoBoard so it would hang over the tub flange. I think it would offer better protection from water ever reaching the back of the tub. The flange of my tub is about 3/8 inch thick. Would notching out that much of the foam compromise the structural integrity of the board?
—I’ve seen someone on YouTube use flashing tape along the tub flange before setting the backerboard on top. To me, it seems like a guaranteed protection from water. But I worry about the sealant adhering to the top of that tape. What are your thoughts on that?
Many thanks. You’ve been a huge resource.
It’s best if you don’t let the first pass with sealant dry. The reason for two passes is 1. to make sure the sealant gets in-between the boards and 2. to make sure it is forced into the board and is one inch on each side of the seam.
You definitely do not want to notch the board if your tub flange is 3/8 inch thick. just set the board on top with a small gap between the tub flange and the board.
Check out this post for more on the tub flange and the tape method: https://www.diytileguy.com/tile-tub-flange-gap/
Thanks again for your reply!
After ordering a bunch of GoBoard Pro Sealants, I read in several places that polyurethane sealants, which is an organic compound, will break down in 5-10 years while caulk can last much much longer.
As a ‘hybrid’ polyurethane sealant, I wonder what the longevity of GoBoard’s brand would be, and that’s a bit disconcerting.
I checked out that link. Would applying Aquadefense, or any liquid waterproofing membrane adhere over the taped sealant? I think that would give me some peace of mind for that gap. Otherwise, I may consider using flashing tape.
You can apply Aquadefense over the seam as long as the seam is filled with mortar and mesh tape. This method is specified in GoBoard’s instructions. But liquid waterproofing over a sealant isn’t an approved method.
I’m planning to use a KBRS pan + Goboard for a shower install. Since you’ve done this, I wonder if you could answer these three questions:
1. Any issues with the goboard not being attached to anything for the bottom 5 inches where it overlaps the flange? Flexing etc?
2. Do you anything to seal between the bottom of the Goboard and the KBRS pan? Like a bead of sealant?
3. I will have Ditra underlay on my floor… any advice about sealing the transition between the Ditra and the outside of the KBRS kerb?
Many thanks
Harry
Thanks for a great post – really useful.
I’m interested to hear your thoughts on the Goboard Wedge shower pan system. I just watched the installation video, and the transitions between the walls and floor, and between the four floor panels, are only done with sealant. No tape or any other waterproofing or reinforcement.
It looks like an easy install, but it seems to me that this is super-risky. These are really exposed areas and it feels like even if it passes a flood test, the wedge boards or subfloor could shift enough over time to cause a pinhole or crack to open up in this bead of sealant.
Any thoughts about this… I’m probably going to go with the KBRS base + goboard on the walls as it feels safer to me for a third floor bath, but I’m curious to know what you think.
Thanks again
Harry
Gotcha, thanks!
Have you used GoBoard’s Seam Fabric? I wonder if there’s any advantage over the regular mesh tape, or is it just GoBoard trying to get a cash grab.
Also, I’m noticing a specific GoBoard LT. I don’t see any documentation on Johns Manville’s site on this other than installation instructions, which is identical to the regular GoBoard. https://www.jm.com/content/dam/jm/global/en/tile-backer-boards/GB-005-GoBoard-Step-by-Step-Guide.pdf
I’ve never installed the KBRS shower pan but, in my experience, a bit of flex between the shower pan and the wallboard is a good thing. A lack of flex could result in the board separating from the pan.
Also, both Schluter and Goboard make a waterproof banding material that would work for the Ditra/curb junction. Kerdi band is what Schluter calls it.
Their wedge pans have been around for a couple of years now but I haven’t had the opportunity to try it out yet. But I believe in the sealant process, in general. However, the more seams and pieces to install do introduce more chance for human error.
I don’t know what the actual data is in terms of banding vs mesh tape. If one performs better than the other or maybe it’s the same thing. But the banding has the advantage of a better surface to adhere to and it’s their brand of product which is better if you are looking at a system warranty.
Thank you!
First off, is there a way to donate money to you? You provide a wealth of GoBoard knowledge that I can’t find on the internet other than Johns Manville’s sponsored videos.
I’ve just finished prep work for GoBoard installation, and plan to tile the entire bathroom, but it just dawned on me that I haven’t seen any documentation or videos on using GoBoard in non-shower or dry areas.
It feels like a silly question, but is it ok to GoBoard the whole bathroom?
Yes, you can use GoBoard in non-wet areas like floors and walls.
And thank you but, no. No donations.
Hi, you mentioned adding blocking to the base of the shower or tub for support, which I’m 100% on board with. Would it be overkill to add blocking to other, or all seams around each GoBoard panels? I worry about deflection, and I’d be on board with adding the blocking if it means having a super solid tiling substrate.
Also, for those looking for GoBoard sealant + their wider head screws, I got a bunch from Contractorsdirect.com. Each tube was around $10, and screws were $35 for a box of 700, far more than what I’ll need. Plus free shipping.
Yes, you can definitely add blocking to the seams and it’ll stiffen things up.
Thanks. Just to be safe, I’ve added blocking to every single seam. I’m also getting a bit OCD, but mostly trying to avoid any situation where I’d regret not doing.
Being overly ambitious as I am, I’ve also cut out an area to install a niche, and want to make sure I’m covering my bases. I’d leave a 1/8″ gap around all the pieces, spread out the sealant 1″ on each side, and plan to use the GoBoard seam fabric as a peace of mind. Is there something else I’m missing, or something crucial for the outside edges, corners, etc.?
Just to be clear, you want to make sure you get the bead of sealant in the gap between the seams and then smooth it so that it forces it in. Generally, having 1-inch on each side is an indication that it’s properly forced into the joint.
Hi Jim. Thanks to your site, I’ve finally started installing the GoBoards. I haven’t got far–I’ve done the back of the tub, but I did everything correctly: 1/8 gap on all sides, GoBoard wide-head screws every 8″, and niche is cut out perfectly. There’s blocking around the tub perimeter, all the seams, and even in the center of each board, to prevent deflection.
One thing I realized is, since I’m covering the entire bathroom with GoBoard, do the dry areas still need the 1/8″ gap + sealant? Or would mesh tape + thinset be enough?
Anything outside the wet area can be thinset and mesh tape. Alternatively, you could thinset and mesh tape every seam and coat over the wet area seams with a liquid waterproofing like Redgard or Aquadefense. GoBoard approves this method, as well.
Thanks for the quick reply! Do I still need the 1/8″ gap between boards? I’m about to cut out boards for the dry areas.
Yes, 1/8 inch gaps.
Hello
Thanks for the great web page. I want to use Go Board. The question I can’t find answer to is:
I do not want to use title over Go Board around by bath tub – I want to use just a waterproof cement (or similar product). That’s the “look” I’m going for. Can Go Board handle a cement surface/coating like that or should I use a cement based product like Wonder Board lite?
Thanks you for your time,
Best,
Mark
ps – if you have a recommendation for the waterproof cement product – that would be very helpful
I don’t know the answer to this. You’d have to contact the company to find out about that.
After months of prep work, I’m about to start tiling. Wish me luck!
This is what the bathroom looks like so far:
https://photos.app.goo.gl/bz27jYa8ywyXFFXT9
Looks good!
From looking though the posts, why do you favor the mesh band over Kerdi band for covering the GoBoard joints? Seems like Kerdi would be better since it’s less porous and would therefore be better to seal the joints especially in the corners vs using mesh. If Kerdi membrane is applied with GoBoard sealant, what chance, if any, of the membrane loosing any of it’s effectiveness after tiled installed?
Would a better alternative be to apply mesh membrane over seams 1st using GoBoard sealant and apply Kerdi membrane over the mesh using GoBoard sealant?
I just finished installing 2 walls of GoBoard for corner shower (separate) that is approx 4′ x 8′ on each wall. I then used a 4′ long square and 1/2 of the top portion of wall is out of square almost 1″. The other wall is much better but when I put a level against it there is an area in the middle where it’s bowed in about 1/8″ inch.
For the 1st wall would it be better to remove the top 4′ of GoBoard that is out of square and shim behind it and reinstall, or float it? For the 2nd wall, would it be ok to leave as is and the when tile installed there should be some allowance to adjust it with thickness of thinset?
After looking at it again, it’s not as bad as I thought. but I don’t understand why each corner is level when I put a 6′ level on them vertically but when I put a square in the corner there is a gap of about 1/4″ between one side of the square and the GoBoard…any idea why? Does this have to be resolved before tiling or can it be adjusted when applying the thinset?
I use mesh tape because I have it on hand, it helps the strength of the joint, and there is less build-up. I think most people apply the tape, like Kerdi tape, with thinset and I’d rather just use sealant. However, if the Kerdi tape is applied with sealant then it does provide a nice surface for the tile to bond to. So, that may be the best way of treating the joint.
The second wall is probably easier to fix. If it’s simply bowed in then using something like a feather finish product and a straight edge that runs on each edge of the wall should flatten that right out.
The first wall could be a challenge if you need the walls to be flush with drywall outside the shower. But, I think if you could remove and reinstall then that would be the easiest option for flattening it out and squaring it up.
It sounds like you’re being diligent with the flattening process and that will pay off when you start of the tile part of the installation.
What you want to do is check your diagonals. So, instead of the square, put your level diagonally across each wall and move it up and down. What you might find is there is a little twisting happening with the walls. If everything looks good diagonally, then I wouldn’t worry about square and simply move on.
Instead of going through the hassle of either feather finishing boards to smooth them out or removing boards and shimming behind them, I’m tempted to remove all the boards and install cement board. If I do that, I assume they’re not as likely not to bow inward in places where wall not perfectly level…correct? I realize will also be a hassle cutting the cement board/waterproofing but I’ve already had to remove one of the walls with the foam board because of bowing. After even removing/reinstalling 2×4’s in one of the walls and thinking the wall level, still having the bowing problem after reinstalling new boards. If I decide to continue using the foam board, can they be reused after removing as long as I drill screws in different locations?
The backer is going to follow the studs. Unless the bowing is in-between the 16-inch stud bay (actually 14.5 inches) which would be a very minimal amount of bowing. So, no, I would not recommend switching out the foam for cement board.
The backer was installed horizontally and where bowing is worst is between the studs (16″ apart). I can remove the foam board and put more studs where bowing is worst and shim if necessary.
More blocking can certainly help stiffen things up but I don’t see how any backer could bow a significant amount in a 14.5 inch span. To meet standards, there can be 1/6th inch of unevenness in 12-inches.
There’s 1/8″ gap in some places within a span of 12″ on one wall and the other wall there’s also the same gap in some areas. And I put a 4′ level on it horizontally and there’s a 1/2″ gap at one end.
I have removed GoBoard on one wall and getting ready to remove the other and will adjust framing, but I decided to install permabase. Some questions:
1) Since I already have the John Mansfield caulk for GoBoard, can it be used for covering the screw heads and mesh tape over the joints of the permabase?
2) Does permabase need a waterproof membrane like redgard applied to it? If not, does a vapor barrier need to be installed behind it?
3) Can Kerdi be applied in corners instead of mesh tape?
It depends on whether you are using Permabase the cement board or the new Permabase lightweight foam board. If it’s the foam board then it would be installed similar to GoBoard and I would think their sealant would work but I don’t know much about the Permabase foam board.
If it’s the cement board then, no, you won’t be using the GoBoard sealand. In that case the seams get mesh tape and thinset, the penetrations would get filled flat with thinset mortar, and then a waterproofing would be installed over the surface.
You can probably install Kerdi band in the corners if that’s what you prefer.
FYI…it’s permabase plus that I plan on installing.
I called permabase tech support and asked following questions regarding permabase plus backer installation:
1) Instructions say to install with 1/4″ gap between bottom of board and lip but doesn’t indicate how much gap between boards. Response: Butt the boards together.
2) What can be used instead of thinset to adhere the mesh tape between joints? Response: Type 1 organic adhesive.
My questions for you regarding the above:
1) I thought all backers to have some gap between them for expansion/contraction…did rep. tell me wrong? If so, what gap you recommend between boards for permabase plus? And is 1/4″ too wide for between bottom of board and pan?
2) Type 1 organic adhesive is same thing as mastic, which you’ve wrote many times is a big mistake to use for wet areas…did rep. give wrong advice here too?
Bottom line is to follow the manufacturer’s instructions. Most backer board manufacturers want a gap. I believe Permabase says “loosely butted”. You don’t want a lot of pressure where they meet. So, if you’re stacking the boards on a wall it’s probably not a bad idea to have a small gap in between. Maybe cardboard that gets pulled out later?
If you want to use mastic to seam them together then that’s your choice. Thinset will outperform and that’s what I would recommend that you use.
Jim, with the risk of sounding like a broken record, I want to thank you again for your help and resources.
From gut to finish, I single-handedly built a bathroom. I watched a ton of YouTube videos, but your GoBoard video and guidance gave me confidence and peace of mind of a water-tight shower.
Everything is pretty much done, with the exception of building drawers for the vanity that I constructed out of an 8-foot butcher block countertop.
I hope the link works for you:
https://photos.app.goo.gl/7z6uBVCcd4bJbjNh9
Otherwise, I uploaded to Imgur as well:
https://imgur.com/a/hgESEHv
Wow! I think it looks really good! It turned out great and it’s obvious that you did a ton of work in that bathroom. Thank you for the follow up photos!
Thanks! When people say most of the work is in the prep work, I wholeheartedly believe that now.
Hi DTG, I have a framing question.
At the beginning of this article, you specify framing requirements as
-16 inches on center
-blocking around the base of tub or shower
-All vertical seams and edges supported
The official JM goboard installation instructions say “Framing members shall be spaced a maximum of 16″ on-center and GoBoard edges should be continuously supported.”
So my question is about horizontal blocking. I know you have to provide horizontal blocking at the tub, but what about blocking behind all the other horizontal edges of the goboard? The official instructions seem to say Yes, but your list (“vertical seams and edges”) implies no.
They don’t require blocking on all of the seams. But if the edge of the board doesn’t fall on a stud then they want that supported. You can block all the seams if you like and some choose to do that but I think it’s overkill, personally.
Not sure where to put this. I have goboard to ceiling as originally intended to tile to ceiling. Kinda want to stop below that & wondering what alternatives there are to cover the goboard. Since it is above the wet zone seems painted drywall mud might work. but not sure its longevity with possible cracking. Thought I’d seen somewhere on web that it would stick & no issues but can’t find anything now that want that info. Being at the top the foam board is nice & solid & don’t see it flexing more than 1/2″ drywall would at that location. Any thoughts?
I’ve heard of people doing what you are describing with other backer boards so I would assume it would work for GoBoard. In fact, Denshield is pretty much advertised for this exact use and it’s surface isn’t that different from GoBoard, at least in regards to accepting drywall mud and paint.
I suppose if you wanted to play it safe then you could just swap out the top GoBoard for drywall. Either way, it would still need finishing.