How to Install Schluter KERDI-BOARD in a Bathroom Part 1 (Step-by-Step)

How to Install Schluter KERDI-BOARD in a Bathroom Part 1 (Step-by-Step)

What’s one of the worst things that can
happen in your tub or shower? Water getting into the stud bay. So how do you prevent that
from happening if you’re doing a bathroom remodel? Well one of the best things that
you can do is install Schulter KERDI-BOARD like this right here that’s behind me. And
in today’s video we’re going to show you how to install all the boards around a tub/shower
surround. In the end you’re going to feel way more comfortable doing this. We’re going
to show you how easy it is to do it. Basically it’s a one-day job. Actually, it’s not
even that. You can probably do this in a few hours and be done ready to tile the next day.
So let’s show you how to install Schulter KERDI-BOARD. You’re really going to like
this video. Let’s do it. Okay, so today we’re going to show you how
to install Schulter KERDI-BOARD around a tub surround to make everything water-proof. What
we’re going to use to make it easy is a pre-made niche. They come in all different
sizes, but this is a 16” x 22”, and it’s already 100% water-proof. So you just screw
this into place. You don’t have to worry about doing any water-proofing on the horizontal
surfaces. And then we’re using a ½” KERDI-BOARD, which is already water-proof. It makes it
really a lot more simple than using a concrete board or a HardieBacker, and then you’d
have to water-proof that surface somehow. So this is like already included with the
surface that’s waterproof. So the things you’re going to need is washers.
These mechanisms you use to secure the boards. And for the seams you’re going to be using
some KERDI band. This is just a 5”, or actually I think it’s 4” membrane that you seam
all the joints that you put in. So this is a very quick and easy solution, and we’ll
show you how to put that together. But it doesn’t take long at all to get that underlayment
for your tile installed. So we’ll get right to it.
First thing, especially when you’re using any of these foam products—there’s a lot
of foam products out there like Schulter; Wedi, there’s a bunch of different companies
that make a backerboard that’s not concrete board. And one of the things you want to be
particularly careful about with that is making sure that all your studs are in line with
one another. Because with the foam, it’s very easy to bellow out that foam. And that’s
going to make it difficult for your tiling, especially when you’re going to go with
like a larger format tile, like a 12” x 24”, if this substrate isn’t totally level,
you’re going to be fighting yourself trying to thinset behind that tile to make everything
level. And you want to fix that at the substrate level rather than trying to fix it with all
your thinset and everything. So for the most part if you have drywall and
the other side of the room is a drywall bedroom or closet, most of the time the studs are
going to be pretty level. But I would say anything that’s more than 1/8” you’ll
probably going to want to address. And what I’ve done in the past is either one shim
out the rest of my studs to do that. Or I’d even gone to where just right in the middle
everything was bowed out, I would actually just use and old planer, a handheld, electric
planer and just plane down that stud until everything is just completely level. So that
is just one important thing you want to do before you go installing this stuff. It’ll
just make your life a lot easier. So we’re going to go head and install the
first board. I’ve made some measurements up where my framing is for my niche. So this
is going to fit pretty much exactly for my pre-made niche. So I marked the edges of it.
And we’re going to cut this out after I have the boarding and then put our niche in.
So it just makes it a little bit easier than measuring and trying to cut around the niche.
I’ll show you that here in a second. So just like any substrate on a tub surround
you just want to come down to that tub flange. You don’t want to go over the flange and
bellow out the bottom. You want to make sure that you’re up above it so that everything
is straight. And then we’re going to come in and we’re going to fill that in afterwards.
So about every 12” spacing on these washers. Just cut that. And that’s one nice thing
about this stuff: it’s very easy to just scribe cut it. I mean if you would’ve done
that with concrete board, that would’ve taken a little bit of time. You actually had
to take it back off and try to scribe it. You won’t be able to just do that very quickly.
The minimum KERDI-BOARD panel thickness for installation on wall framing with stud spacing
at 16” on center is ½”. Now the other thing to know is the maximum on center fastener
spacing is 12”. Okay so we’re going to cut out our niche.
4 5/8”. This is going to be like a first rough cut, and I’ll be cutting it closer.
Now I can see my framing. Cut this out more to be able to get the niche in it. Something
you definitely couldn’t do with concrete board. If you did you’re probably going
through six plates by now to do it. So we got our niche. So now we’re just going
to outline what I need to cut. I want to make sure this sits level or sits properly with
spacing. 17 7/8”. So I’m actually going to hold that in place to cut around the niche.
You don’t have to be worried about too much precision with this because you’re going
to be still doing a KERDI-BAND membrane that’s going over the seam. But the tighter it is,
the less thinset you’re got to use. The better it looks, too. There you go. That’s
fits pretty nicely. Like I said, we’ll be doing a membrane that
goes over the top of this. So even if the joints aren’t all that great, you don’t
have to worry about it. You don’t have to redo another sheet. But then with these washers
you can pinch both sides of that, and that will be enough to hold it in secure. So you’re
kind of using less washers that way. You use the same method to save screws and
washers when attaching the KERDI-BOARD panel to each other. So you can pinch the screws
and the washers adjacent to the KERDI-BOARD panels.
Make sure this feels all flush. That’s pretty good. Okay so we’re ready to go on to the
next sheet here. So that’s why the nice thing about using
a board that’s already water-proof is that when you put it all the way up to the ceiling,
it’s water-proof all the way up against your drywall. Versus like when you use a liquid
membrane, it’s usually pretty tough to try to get that last little ¾” without getting
it all over your ceiling. And that just makes it tougher to do your drywall work. So having
this straight up there makes me feel better that everything’s water-proofed on this
wall. So that’s just one benefit of having something consistent like this. 25 ¼”.
I’ve bellowed out on my ceiling here. So I’m just going to scribe cut off this KERDI
so it could meet tightly up against the ceiling. That makes it a lot nice and tight up there.
So one of
the great things about the KERDI-BOARD is that the gridlines they have on board just
makes it so easy. I don’t even need a chalk line to cut anything up, and everything is
straight with how the board is laid out. So it really makes it easy. Not only that, but
just to line up your screws and stuff. You just follow those lines all the way up to
follow your stud. And if you want to pull out the chalk line, you don’t have to kind
of guess where your stud is. That saves a little bit of time.
Okay so we put on our second board and again, we’re just keeping it right to the top of
the tub flange, which is about ¾”. Every tub flange is a little bit different. But
we’re just resting this board on top of that flange. And then we’re going to fill
in that tub with the water-proofing membrane afterwards.
So I’m going to use a chalk line on this one since it’s pretty far off where my drywall
is meeting, basically like 31 1/8” to 30 ¾”. So it would be kind of hard to use
those lines and be right on. So I’m just going to use a chalk line on the off square
cut we’ll be making. So for this one, we’re going to measure
up the top of my tub to the center of my tub spout. So 1 ¾” x 13 ¾”. I’m just going
to use my utility knife to cut a square hole botch. But being so close to the tub there,
when I put my band around the bottom of the tub, it’s actually going to go over all
of this, including the pipe. So I’m not too overly worried about the size of the hole
that I’m cutting for it. That’s just for my pipe. See I just pumped that through for
my valve. So now I can just get my 3” hole saw. Cut pretty nice through there. So I just
have some integral stops on this valve so I cut out a little bit more on the sides to
access that. So you’ll want to be able to have access to these. These are the turn on
and off to this valve. They’re called integral stops. I just notched a little bit more out
of this so that I can actually access them. And then basically I can just thread in my
face plate. So as long as I have my towel right around where my KERDI is, it would be
good to go. I’m making a little impression on the back
there so I know where my shower connection port is going to be. So I’m just going to
use a power bit for that. All right so then I like to use some of the
KERDI-BOARD and go all the way down alongside the tub so that everything’s water-proof
that’s touching the tub. We’re actually going to use the membrane over the top of
this, but I definitely like to use the KERDI-BOARD against it as well, rather than drywall for
obvious reasons. If this drywall gets saturated for any reason, it’s just going to crumble
apart. So you’re better off to have some water-proof right against there. About 1”.
About 3 lines. Okay now we’ll quick corner beam on this
side. We’re going to use galvanized screws on all these because we’re going to be in
the tub surround area. Just a good way to check your corner beam using your square to
make sure that an outside lip is sticking out so when you go to feather your drywall
on here you’re not going to see the edge of your corner beam. It’s going to cover
all of that. The tub surround side doesn’t really matter because we’re tiling all that.
What is definitely important right here. I’m hitting the edge of my corner beam. I make
sure I pull this out a little bit so that this sits nicely.
All right so that is how you install Schulter KERDI-BOARD. Again this is part 1 of 2. So
we’re going to have another video coming down the road for you. You can check that
out. If you like today’s video, give us a thumbs up on YouTube. That way other people
can find it. You can also subscribe to our YouTube channel because we put out a new video
every single week. And if you’re doing a bathroom remodel—if you’re beginning or
if you’re in the middle of a bathroom remodel, and you want to look at more videos, watch
more videos and get coaching—you should check out Bathroom Repair Tutor. Bathroom
Repair Tutor is our membership website where we have over 80 video tutorials. And the reason
why you should check it out is we also provide coaching for you. You can ask an unlimited
number of questions and get answers specific to your project by joining Bathroom Repair
Tutor. It’s pretty awesome. It’s kind of like having a coach right next to you while
you’re doing your renovation, and that’s the whole reason why we started it up because
we’re passionate about bathroom remodeling. We want to help you begin and complete your
project and have an awesome-looking bathroom in the end. So check out
for more information on that. We’d love to have you as a member and inspire you to
get started or finish your bathroom project. So thanks for watching today’s video. Take
care. We’ll see you next week.

49 thoughts on “How to Install Schluter KERDI-BOARD in a Bathroom Part 1 (Step-by-Step)

  1. What did you do for the seam on the ceiling? I see some guys tile up to the row before the niche before they install it so they can match up the grout lines. Schluter makes pipe and valve seals.

  2. Hey Sandra McRitchie1 those razor knives have a button to release and lock the blade. They have been around for about a decade now…

  3. I am sorry guys but this material it's worst than hardybacker or wonder board. I understand this crap it's only for homeowners or rookies I'm a professional tile installer I float my walls and floor with cement. This video it's really sad.

  4. Its 1/2 in Kerdi board all around? It looked thicker in one of the angles, but it could be illusion. After you install this, you put the unmodified thinset and the tile and you are done? Wow, sounds too easy

  5. What size screws did you use for the 1/2 board & do you have to use the curb or is the slant on the tray good enough for a 36x36x34 shower?

  6. Hi guys, great video, one thing I would like to add, I have seen another video where the installer, seamed a very knowledgeable dude, when the walls were out of plumb, he did a tinset layer on the studs behind the kerdi board, then put the boards in and wiggle them till they were plumb and square perfectly for the tile to be perfectly square every where, waited a full day for the tinset to dry then did the screws. I understand you can do spacing or planner the studds to the point where they are all even but this way seams really kool and easy, down is it needs an extra day for the job to be done. Mainly for walls that are waky out of level / plumb. Keep the great work.

  7. Hi Jeff how should I transition kerdi board to an outside corner of drywall?? Should I use a corner bead and skim coat the dry wall side and just thinset the kerdi side??

  8. Is it okay to let the Kerdi Fix dry before applying the thin set & Kerdi band? We just applied Kerdi Fix to our tub lip this weekend and thought we should let it dry first before applying thin set over it.

  9. Guys I bought a 3" hole saw to cut the hole for my Delta mixing valve . Kerdi has a flange , but I'm not going to bother using it considering I am going to have a Delta diverter valve above the mixing valve , and the flange would be to large to cover with the diverter bezel . The sad part is , the diverter sits inside the Kerdi board , not extended out like the Delta mixing valve . Sad design imo by Delta . I'm trying to find a socket to fit the bonnet , as it's not very accessible. No socket that big available in our town of course

  10. why not make a 3/4 notch on the bottom of board and lower the board closer to the tube eliminating chance to leaking ?

  11. A favorite practice of mine re: leveling wall studs, is to apply a 3/8" bead of e.g. pl-200 to the studs (severely warped studs, as indicated in this video require add'l attention) I then tack the board up to hold it in place while the adhesive sets, after which I add further screws. With Durock or Wonderboard type materials I pre-drill holes so as not to compress the adhesive. If you're lucky you may even be able to plumb the boards, assuming the studs aren't too out of whack. It adds strength and reduces board warp considerably. It's worked for me for decades.

  12. This guy I been working for says that kerdi board is harder to install that kerdi membrane, I been remodeling for years but just got introduced to kerdi system… IMO kerdi board would seem like the better way to keep things level & square

  13. I so appreciate your videos. I'm an experienced woodworker / do-it-yourselfer, but have never done a tile shower before. I'm completely renovating both of our bathrooms. Thanks to your videos, I went with Kerdiboard and am in the process of installing it in the first bathroom as I type this. Every stud in our 50 year old house in the tub surround was either bowed or warped, so I had to screw studs to the existing ones to level the entire surround area up. I've been watching your tile install videos also. Thank you!

  14. Great video but try being a little more careful with the tub, maybe try covering it up so you don’t damage it 👍🏻

  15. "Anything more than an 1/8" inch out y'all wanna address" my sides are hurting the way he delivered that statement

  16. I’m sorry if this has already been asked. So no insulation behind the niche? Our shower sits on 2 exterior walls and I was planning on a niche on one of them. I wasn’t sure what to do about the insulation. I assumed just squash it with the niche.

  17. with all the comments I wonder since I won't be tiling my walls I'm using barn tin or roofing tin will this be a good product for me to use?

  18. What can you do if you have to shim out the tub surround for the kerdi board? Where the kerdi board meets the drywall is now a difference off 2/8 of and inch

  19. great job, I like the USE of a drop cloth or cardboard in the tub to protect it , this material is a great product all I use,

  20. Schluter now says it’s acceptable to build up studs with mortar for leveling Kerdi-Board, not their actual recommendation but acceptable so that it doesn’t void their warranty to do so.

  21. any idea if i should still add a plastic 6 mill to cover the insulations? my bathroom wall on the other side is my garden

  22. Have you done a kerdi pan with Hardi walls? I have an old house and I am worried about deflection in the exterior wall the shower will be in. I'm concerned that the 1/2 Kerdi on the wall will not hold the tile if it has movement

  23. can I put backer board behind this to strengthen it?. I have a double wide trailer and the studs are not conventional 2×4..

  24. I went to the store today and checked it out. It worries me that a slip or kids hitting or pushing the wall would crack the tiles. It’s super flexible.

  25. Could aqua defense work on the seams/joints rather than mortaring with the kerdi band? I'm going to be going over the whole wall with an adhesive shower wall panel by Swan (caulking the corner seams of course) and am using Kerdi as a light weight structural backer for this panel. Thanks! (added note for info, I am using a sloping shower pan by Swan as well)

  26. Excellent production of you videos. Thank you. I have a question regarding the valve seals. I am installing body sprays in the shower I'm working on that requires a 3 inch hole in the wall board. It doesn't look like Kerdi offers a seal for this. Thoughts on how best to seal a 3" hole?

Leave a Reply

Your email address will not be published. Required fields are marked *