Advice on Gap in Waterproofing Bathroom Floor

[Herostratus44]

Hi Everyone

I would really appreciate any advice on how to fix this. My contractor installed Schluter Kerdi waterproofing membrane on the bathroom floor, however I have just noticed two gaps where for some reason he did not use the Kerdi tape on the corners and on part of the wall. (see the two attached pics) The location is where the glass door for the shower will be installed. We waterproofed the entire bathroom floor

How much of a problem is this? To me the waterproofing seems to be useless if there are gaps in it, however they have already installed the tiles. Do I insist they rip up the tiles and waterproof correctly or is there a caulk/sealant/other solution that I could use instead? Or am I getting stressed over nothing?

Many thanks in advance for your suggestions/advice

[cx]

Welcome, Herostratus.

Can you back up a little and give us a photo or two showing some perspective of what we're looking at?

Kerdi is not what one would normally use on a bathroom floor at all, even if he wanted it waterproofed, which is generally not necessary.

That said, any waterproofing system with gaps left in it is no waterproofing system at all.

My opinion; worth price charged.

[Herostratus44]

Thanks for the response! I have uploaded a photo of the entire shower area. The two gaps are at the transition from the bathroom floor to the shower floor. The entire bathroom floor has been waterproofed with Kerdi membrane and there is supposed to be a band of Kerdi tape at the join between the floor and the walls. For what ever reason he didn't do the corner on the right and the wall on the left - the areas ringed in red

Those tiles have been down for about a week I don't know how easy it is to remove them without destroying the waterproof membrane and heated floor system underneath? Do we need to rip out everything and start again?

I'm sure my contractor will suggest filling the gaps with something like Kerdi-fix but would this be adequate?

[cx]

Originally Posted by Herostratus

I'm sure my contractor will suggest filling the gaps with something like Kerdi-fix but would this be adequate?

If you paid for a waterproof room, no, that would not be adequate.

1.What is the subfloor in the bathroom to which the Kerdi membrane was affixed?

2. How was the entry door opening to the bathroom waterproofed?

3. What was the purpose of the waterproofing of the bathroom floor?

Seems to be a scarcity of fasteners for the foam board on your walls.

My opinion; worth price charged.

[Herostratus44]

1. The bathroom floor is a concrete slab, with a warmup heating system on top of the slab. The heated floor system is covered in thinset to which the Kerdi membrane is attached. The floor tiles are on top of this.

2. The bathroom door is not waterproofed as the bathroom floor is higher than the outside floor.

3. Protect the electric heated floor system underneath the tiles. Whoever converted the industrial building into apartments also built the walls first and then put down a six inch concrete slab on top of the original slab so the framing and drywall goes into the concrete - the waterproofing at the bottom was to minimize any water leaking into these voids.

4. Thanks - I had not considered the lack of fasteners but they are definitely too far apart vertically -almost 2 feet. I will have him add more.

Is it possible to remove just some of the tiles to fix the waterproofing or is the entire floor going to have to be trashed?

[cx]

1. Understand. The manufacturer of the Kerdi membrane would not sanction that installation, I don't believe. You might give them a call on that (888-472-4588). I suspect they'll tell you to use their Ditra product in that application, along with the KerdiBand to tie it to the walls if desired.

2. So, you've effectively directed any flooding of the bathroom out to the adjacent hallway.

3. Bathroom floors are generally not considered to be wet areas. It's not uncommon for folks to waterproof the floor a foot or two outside the shower, but waterproofing the entire room is generally not considered necessary. If you just want yours waterproof, of course, that's entirely up to you.

While your construction is not something I've ever encountered before, I don't see that it changes the overall function or requirements for a bathroom floor. Again, if you do, that's entirely up to you. But, as I said earlier, if a fully waterproofed floor is what you contracted for and paid for, you're on very firm ground in claiming the contract has not been fulfilled. You have a written contract for this work?

5. Probably not. Removing tiles from that type of membrane very commonly damages the membrane beyond its usefulness. And especially in your case, where you'd need to get down to clean membrane - without any thinset mortar buildup - in order to bond the KerdiBand, it's unlikely to be successful. But you can certainly try.

My opinion; worth price charged.