Hey Tom, I don't necessarily think cement board is better, rather I'm almost 70 years old and if this thing fails in 10 or 20 years I won't be a happy camper. At this rate, I'd rather touch each of these jobs only once and then go on to the next. If it costs a few hundred $$ more...so be it. Belt and suspenders.
I've already installed a wall mounted vanity and a wall mounted Kohler toilet. Working around the 3 1/2" roof vent was a real PITA but well worth the effort. This makes it so easy to swab the floor, I should have done this 15 years ago. No more on your hands & knees stuff. Besides, with the in-floor heat the cats will love ❤️ it.
I'm cutting into the floor joists to get the needed pan depth. Then I'll be sistering in additional 2x10 members to support the structure properly.
The drain will be the Schluter 4" square stainless version. I wanted to use their trench drain but the dimensions (drain pitch) just didn't work out.
Thanks for the reminder on the flood test. After I redid the shower plumbing, I decided not to install the cement board and just observe the new plumbing for a couple of days. I'm so glad I did, there weren't any leaks but its nice to know that...rather than sealing up the wall and then find water dripping from some where it's not supposed to.
If your looking at longevity Kerdi board or Wedi will out last fiber cement. They are lighter, easier to cut and install. I use 2" Kerdi board for structural members in showers. Schluter Kerdi over regular drywall is warrantied by Schluter for 25 years.
After a few cable installs it's easy to figure how to weave it. Make sure you maintain the 3 lug spacing. Easiest way to install it in the mat is a urethane grout float. Align the cable, run the float over it, presses it in place. Do all 3 tests the three required times. I take a picture of the meter with the cable tag in frame while doing each test. I keep the photo in a file, send copies to the owners. You'll need the KW off the tag to program the t-stat. Register the warranty online.
When cutting the joists, don't forget the 3/4" subfloor in the depth calculation.
Surprised you could not get an L or LS pan to work. Picture is an LS pan, like yours the joists were trimmed, then sistered as needed.
The shower has about 12 uses on it since it was remodeled. They quit using it 3 months ago, there was still 16" of water in the wall.
Jeesh! Surprising how often stuff like this happens.
Clients are usually completely emotionally shot by the time they call you.
Thanks for posting very interesting.
I got the shower waterproofed today.
Kerdi board installed, washers and screws will be covered.
Three band sizes I use, 5, 7, 10 inch.
Two seals for the system. The shower arm seal will not be used on this one. The shower arm comes out of the ceiling.
Formed corners, inside and outside.
Removing old drain hub. Socket Savers, great tools.
Dry fit, the pipe will get vacuumed out. There are pipe shreds in the trap weir.
Curb set, Kerdi over base. I cut the Kerdi 4" over sized folded and mortared the over cut to wall, saves band. Used preformed corners.
A barrier free shower should have a pitch towards the drain. The slope allows you to fill the pan area. Pictured is a barrier free pan. It was flood tested once all the waterproofing was completed.
The subject shower is not barrier free, that is the curb in the bottom left of the picture.
For future plans, consider studding out the wall and making a full-width shelf instead of a boxed niche. We did that in our master bath and it's worked out fantastically. We had enough room to allow for studding out the wall with another 2x4. This to allow having a 60" wide niche running the whole width of the shower. The ledge is a piece of Silestone (same as the counter tops), cut with a slight curve from the sides, bowing out to about 1/2" at the center. This to allow for greater depth at the center without having the ends look oddly cut into the side tiles. There's a slight tilt to allow water to slough off, but not enough to cause things to fall/roll.
Now with a whole width shelf we don't have any problems with his & hers niches or lack of space.
All of our new baths were done with Kerdi. Including one linear drain. Totally worth it. I'd done a remodel of a bath some years before with cement board and Redguard (the old stuff that dried to 'axe murder crime scene red'). And while it withstood the test of time, it was nowhere near as simple and quick to do as Kerdi. Vote me in the 'never lug cement board again' crowd.
Yeah I guess the thing I've never understood about flood testing barrier-free showers is that you're [technically] supposed to test to a certain height above the drain...2"? But you can't necessarily reach that height over the drain in a barrier-free depending on where the drain is located and if you're using closer to the minimum pitch. It's probably not a big deal if you're not having the inspector standing right there when you flood test but I was just wondering what the protocol is if you can't achieve 2" with the drain config and pitch you've chosen. It'll be an issue for me in a few months when I get to my first barrier-free.
For the record I wouldn't bother using anything other than Schluter products either, though I have yet to use Kerdi-board...have always used Kerdi over cement board.
Schluter is the way to go - love the stuff and easy to apply and works as advertised. Expensive, but the cost of water damage is worse.
I like that design idea. Might have to present that to the boss for upcoming shower. I'm curious about the caulking detail on that - how did you end up caulking it to prevent water build up between shelf and Kerdi?
For future plans, consider studding out the wall and making a full-width shelf instead of a boxed niche. We did that in our master bath and it's worked out fantastically.
Saw this at the local Kohler/Robern store...pretty dramatic, it definitely made an impact on me. The elegant linear lines...This is what I was going to incorporate into our present bath remodel until I found a cold air return in the way.
The cost of rework is even more mind numbing. Touch it once and then proceed to the next project.
The code required 2" applies to curbed showers only. Seeing as there is no curb, they can't require the 2". This may change at some time, but so far it applies only to the curbed showers. If I had to flood a barrier free to 2" I would run the band up above the floor line 2", hot glue some backer to the floor, flood the pan.
I did have one barrier free we did as a wet room. Blocked the door and flooded the entire room to 3".
Kerdi board is lighter to carry, cut and install. I have the CMT fiber cement blade for the TS-55, still easier to cut Kerdi board. Material cost is higher, I find it is cheeper in the long run with the labor savings.
I've done full length niches. Final design is the customer decision. I've seen some baths where a 5" niche would get overloaded.
Wow, just came across this. Great read.
Thanks Tom for sharing your knowledge!
Tom do you cut Kedi board with a knife or saw?
What is the goo used to seal patches in the wall?
@tjbnwi Tom- In these showers that you show what thickness is the Kerdi Board on the walls? And you are screwing that right to the studs or is there something in between?
I'm not Tom, just answering your second question since I've used Kerdi a fair bit as well. Kerdi is applied with thinset (example if you are applying the membrane to cement board). When you overlap or use the thin bands of membrane (e.g. at the corners of the pan), also thinset. Or, in Tom's photos, the patches of Kerdi membrane on top of the Kerdi-board to cover the screws are also applied with thinset. This works because the membrane is kind of a fleece-like material sandwiching the impermeable core.
Schlüter also sells an [expensive] silicone caulk called Kerdi-fix for use on drain flanges, metal trim, pipe and valve seals, etc.
The typical Kerdi Board install is 1/2" thick on the walls. It is screwed directly to the studs. I typically cut it with the TS55, low speed and a 28t blade. Cuts easy enough with a utility knife and a straight edge too.
Live4 has it right about the patches. They are Strips of Kerdiband applied with unmodified thinset.
The KerdiFix caulking IS NOT silicone and it's advised to not use silicone in the assembly. Or it used to be anyway. I don't know what's in that kerdifix , but it's expensive , smells awful, and sticks to everything like nobody's business. It's now available in smaller tubes so there's less waste if you don't use a full tube. It has a short shelf life once opened. I know guys found an alternative from Sika that was a spitting image to the Kerdi product , but I'm pretty sure it's been discontinued.
Sorry, technically it's a proprietary "silane-based polymer," didn't mean to imply it's the same as any random silicone caulk.
Depends, normally the TS-55 with a 48 tooth blade.
The goo is tile mortar, Schluter All-Set to be exact. I'm not calling it thin set because Schluter claims you can set LF and LFH tile with it. I'll find out how true this is soon.
I'm sure it is since that's what is spec but is a 1/2 foam panel rigid on that wall?
With large format tiles I could see it but with a mosaic I would worry the wall would be spongy.
It's a very dense compacted foam. Not that flexible.
I've never done a full wall or large area of mosaics over it.
This has been a very interesting discussion. Thanks for the education Tom. Altho it has been well over 30 years since I had anything to do with the trowel trades, it is amazing to me the improvements that have been in materials. if i were to start in again, it would take a lot of educatin' just to catch up. My grandson is just starting in college with his major in construction management. Every time I see him (weekends) I have lots of questions to ask.