“So what do you think is the best way to
waterproof a shower or a bathtub surround?” This is a question I get a lot over on Home
Repair Tutor. So today I wanted to make a video and show you how to waterproof a shower
or a bathtub using three different methods. So this is going to be really cool. And in
the end I want to get your input on the three different methods. So stick around because
you’re going to like this video, and I think it’s going to bring up a lot of insight
and new skills that you may not be aware of—and that’s always kind of cool. So let’s dive
into it right now. The first method to waterproof your tub is
with cement board. Replacing 1” spacers on the tub deck such that the cement board
will sit above the tub lid. And then Steve, my co-founder over at Bathroom Repair Tutor,
is marking the position of the prefabricated niche on the cement board. What he’s going
to do is cut that out. So first, what Steve is going to do is make
a chalk line on it for the horizontal location. Then he’s going to mark the vertical location
using 2”x4”s and then cut it out using an angle grinder with a tile saw blade. So
that’s how you do that. Now here’s the deal: You should only be
using alkali-resistant screws when installing cement board. Put them in 1” from the edge
and then 8”-10” within the field of the cement board.
So Steve is dry fitting the top piece here, and again, he’s just going to cut out a
section so that the cement board will fit around the niche. So again, 8”-10” with
the alkali-resistant screws within the field, and you should be good to go.
Now another way to cut cement board is with a utility knife or carbide-tipped knife with
a square—so in this case a drywall square. We’re putting the piece of cement board
up on the back wall, not the plumbing wall. Again it’s 1” above the tub deck. Place
your screws in place. And then we’re butting the cement board up against the drywall for
this back wall as well. So for the plumbing wall, you’ll always
want to have your drywall in place first. Then get your measurements for the mixing
valve. Transfers those to the cement board along with the tub stop measurements. And
then what you can do is make perfectly cut holes for this. Steve’s using a 1” paddle
bit for this, nothing special. And then for the mixing valve, he is going to be using
a 3” hole saw. So they’ll give you perfect cuts for the holes for the tub spout and the
mixing valve. Place your cement board 1” above the tub deck again, and then screw it
into place. You do the exact same method for the shower head hole that’s above the mixing
valve location. So again, just use a 1” paddle bit, and your ½” copper will fit
right through there for the shower head. You want to butt the cement board up against that
drywall. So in this case, we had to put a little piece
of cement board in place between the tub and the drywall.
Now you have to waterproof your cement board. There’s no getting around this. We’re
using Ardex 8+9 in this tutorial, and they use a mesh to help out with all the different
transitions. So what we’re doing is placing green painter’s tape—use any kind of tape—to
put it on the tub deck and fill in that gap between the cement board and the tub using
the Ardex 8+9. That’s going to waterproof that space. And then you’re going to put
mesh over top of that. Steve right now is rolling on the Ardex 8+9 to waterproof all
of the cement board. Again, you have to do this in order to ensure your cement board
isn’t going to leak water through it. So as you can see, Steve is using the Ardex 8+9
mesh here. We’re using that in lieu of alkali-resistant tape because that’s what the Ardex 8+9 directions
call for. You can also use Hydro Ban, Red Guard, etc., but you have to waterproof cement
board. It’s a must. And when you’re done waterproofing, pull the painter’s tape up
from the tub deck. The second method is Schluter KERDI BOARD.
You want to make sure that your walls are nice and plumb and level. What we like about
KERDI BOARD is it’s light. And again, you want to mount it right above the tub lip using
their screws and washers. The nice thing about KERDI BOARD, besides it being light, is it’s
easy to cut. So you can score it with a utility knife; it’ll cut easily. You can trim it
that way. So they have specific instructions on how
to install it. You want to put a screw and a washer in every 12”. And your stud should
be 16” on center at a minimum for a ½” board. But follow the Schluter instructions
and you should be good to go. So again, the nice thing is you can score
out the area where you want to put your niche. Then you can install your niche, trace around
it, cut around it with a utility knife, and then you can install the niche in that location.
That’s what Steve is doing here. He’s picture-framing that Schluter KERDI BOARD
and then placing the niche within the stud bay.
So anyhow, you can pinch the niche to the KERDI BOARD using the screws and the washers.
It’s very simple to do. Anybody who knows how to use an impact driver or drill can do
this. So the KERDI BOARD’s easy to use. I’m pretty sure any DIYer can install it.
So again, you just score it with a utility knife. Actually, it’s easier than drywall.
Steve is cutting the last board that we’re putting in place here between the ceiling
and the first KERDI BOARD. So again, you can just scribe cut it, no problem.
We make it flush with the ceiling. So nice flush cut, install it using the screws and
the washers, and you should be good to go. Just super simple to use. And the nice thing
about it is it has gridlines on it, so you can cut it easily.
So here’s the back wall. Very similar to cement board. You just put it in place. You
want to cut everything to size. And Steve is actually cutting out a hole for the tub
spout using a utility knife. He places the board on the wall, and boom, he’s going
to hit it there, puncture it to mark the location of the mixing valve. And then he’s going
to cut out the mixing valve using that same 3” hole saw. So, super simple. Anybody can
do it. So again, you just put everything in place. Put a little piece of KERDI BOARD between
the tub and the adjacent drywall. Now what we did is mix up some unmodified
thinset. So unmodified thinset, pancake batter consistency—you’re going to put this in
the space between the tub and the KERDI BOARD. Now this is Steve’s preferred method. KERDI
doesn’t recommend this, but this is what Steve likes to do. And then you can put the
KERDI BAND over top of that. So you embed the KERDI BAND into the unmodified thinset
using a 6” drywall knife. You do the bottom positioning first with the KERDI BAND.
What we’re explaining here is instead of using the unmodified thinset, you can actually
fill in that gap between the KERDI BAND and the tub using KERDI-FIX. So you put KERDI-FIX
in that gap. Then you put unmodified thinset on the KERDI BOARD and embed your KERDI BANDS.
So that’s the Schluter-preferred method for waterproofing between the KERDI BOARD
and the tub. So if you want their warranty to be upheld, you follow their directions.
So in this case, what we’re doing is we’re applying unmodified thinset to the corner.
Then we’re overlapping the KERDI BAND over top the bottom band that we just put in place,
again just using the 6” drywall knife. So KERDI BOARD’s really, really easy to
install. I can’t emphasize that enough. You want to put the KERDI BAND wherever two
KERDI BOARDs meet, wherever the niche is embedded into the wall—so you want to put the KERDI
BAND there. And then you put the unmodified thinset any screw and washers and put a little
strip of KERDI BAND over top of those. That way when you smooth those out, you’re going
to waterproof all the screws and the washers. And a little nice tip here is to kind of smooth
that out using a damp sponge. And that will give you a nice, solid surface for your tile
to be adhered to. So the transition between the KERDI BOARD
and the drywall, again you just use KERDI BAND. You want to smooth out or take off any
of the thinset that is left on the drywall. The third and final method for waterproofing
a shower or a tub is to use Wedi building panels. Now we like these a lot because they’re
easy to install like KERDI BOARD, and you use screws and washers just like you do for
KERDI BOARD. Now Wedi makes their own screws and washers, and we recommend that you buy
those because they’re obviously manufactured for Wedi building panels. And they have their
own specifications on how far you should be installing the screws and the washers from
the floor and within the field. You always want to apply the Wedi joint sealant on top
of adjacent boards, and embed one board on top of the other board, and sandwich it together
using that Wedi sealant. Now Wedi is easy to cut, too, so Steve just
used a paddle bit to cut that hole in it. And what you do is you can pinch the washers
and the screws in between the two boards. You can do this, too, with Schluter KERDI
BOARD. And then you smooth out the joint sealant—we’re going to touch that further a little bit later
on in the video. But you want to smooth out that joint sealant.
You can cut the Wedi building panel with an oscillating multi-tool or a utility knife.
You can build out your own niche using it. All you need is the Wedi sealant, the Wedi
building panel, and the screws and the washers to build a custom niche. It’s really that
simple. And it’s cool for older homes that have really weird dimensions.
So again, you can cut out your hole for the mixing valve using a hole saw. And then you
want to apply Wedi joint sealant on any joints and any washers and screw holes, and that
will waterproof the Wedi building panel. It’s that simple. It’s actually even simpler
than the Schluter KERDI BOARD. But each method has its own pros and cons. So again, we added
another layer of the joint sealant on all of the transitions between Wedi building panels.
That’s what you want to do. That’s what Steve is doing here for the custom niche.
We built this walk-in shower in only four hours using the Wedi building panel. And if
you wait two hours, you can actually start tiling over top of it.
So those are three different methods for how to waterproof a shower or a bathtub. I hope
that you like this video. Lots of really great new concepts in it. So down in the comments
here on YouTube or back on over at HomeRepairTutor.com, let me know which one method you would use
in your bathroom if you were to remodel it. I think it’s really cool to open up this
discussion because in the comments I typically end up answering a lot of questions. So that
is it for today. Oh, the other one thing I wanted to let you
know about is this: Steve and I came up with a free bathroom remodeling video series for
you. So this is great because it’s going to help you remodel your bathroom faster,
easier, and cheaper by showing you different skills, like the ones we went over today.
You can check that out right here. So just click right here, it’ll take you over to
the sign up form, and you’ll get that instantly today.
So that pretty much is it. That wraps up the video for this week. Remember a new one comes
out every single Tuesday at 8 am, so you can count on a new video every single week, and
I don’t want you to miss out on that. You can always subscribe by clicking the subscribe
button here. All right, I’ll see you down in the comments.
Have a great day. Thanks for watching. Talk to you soon.
I accidentally hit this button which sprays this shower head. It went all over me while
I’m shooting the video. Funny stuff. That’s what happens when you try to make YouTube
videos in the shower.