Is my GC competent? [Archive] - Ceramic Tile Advice Forums - John Bridge Ceramic Tile


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07-20-2019, 07:49 PM
Hey, I could really use some advice from you tile pros...

I'm going to attempt to briefly summarize this 9 month nightmare. Our master bath sits over our garage. Last Fall, we noticed water spots in the ceiling of our garage. It turned out that the majority of our bathroom subfloor had extensive water damage plus mold in it. The insurance adjuster and 3 separate GC's all believed it was from our shower mud pan slowly leaking water into the subfloor, etc. We had the bathroom completely remodeled (entire subfloor, etc) and was finally completed in January.

In April, we noticed that grout was cracking in several spots on our new shower floor. The GC came back and said that his tile guys probably just mixed the grout "too watery" so they tore out those grout lines and then regrouted. I certainly wasn't educated enough on the topic, so I just went along with his theory/explanation.

A few weeks ago, we noticed that those same grout lines on the shower floor were cracking again but ALSO grout lines were cracking on the shower wall and that a tile at the top of the shower wall had cracked in half. We also noticed that there were subtle water spots on our garage ceiling again. The GC came back out and said this had to be a plumbing issue, so he went up thru our garage ceiling once again and noticed that the shower subfloor was once again saturated. We had a plumber come out and he couldn't find any plumbing leak. The GC now claims this is all occurring b/c of our "house settling" (seems completely bogus to me - our house is 7+ yrs old).

After the GC and I argued over this for the past week, he finally agreed to tear out the tile on he shower floor to assess the mud shower pan. He found a large crack in the mud shower pan that ran from the shower wall to the shower drain. He has finally agreed to tear out the shower pan (but not the subfloor) and the first row of shower tiles. He says his plan is to just apply more Hydroban in these areas and build a new mud pan. The shower walls are hardiebacker coated with Hydroban and the shower floor consist of the plywood subfloor, hardiebacker coated with Hydroban over the subfloor, then the mud pan.

In my mind, I think of the cliche thats says the definition of "insanity" is repeating the same steps over and over yet expecting different results. It seems to me that the GC's plan to repair our shower is not adequate since his way of doing things lead to an extensive leak within the first 6 months of our new shower?

I would like to ask him to at least install Kerdi membrane over the hardiebacker cement board that is on the shower wall and on top of the new mud pan that he is building but it appears to me after reading these forums that is probably not a good idea since the shower walls already have Hydroban over the hardibacker??

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07-20-2019, 08:07 PM
Do you have any pictures of the shower building process that we could scutinize? The method you mentioned gor a shower pan does not conform to any standard or manufacturer instruction. It sounds like your shower was not built to any acceptable standard and the excuses coming from the GC are a huge red flag. Who picked this GC? Was it your find or someone your insurance suggested?

The method you described of bulilding a shower pan is so wrong it describes someone who has no knowledge and frankly no business building a shower. Are you sure the hydrobam did not go on top of the mud bed? Also can you take a picture of your drain? ? Hydroban requires a specific type of drain. It can also be built with a conventional shower drain but it requires a very specific installation that clearly wasnt followed here. Again any pics will help.

07-20-2019, 08:57 PM
The first pic shows the shower floor after the tile was removed. The crack that ran from the shower wall to the drain is the darkened area that looks wet

The 2nd pic shows the shower after the GC removed the mud shower pan, the first row of wall tiles, and the entire left side the shower shower wall (it was the wall that had cracked wall tiles and grout lines). The foam insulation on that exterior wall is over a vent pipe.

To clarify, this 2nd pic also shows the floor with the hardiebacker board coated with hydroban. The cracked mud pan was built over this hardiebacker/hydroban that is in this pic. I believe the mud pan also had hydroban over it as well. Under this hardiebacker, is the plywood subfloor.

3rd pic is the shower drain.

07-20-2019, 09:12 PM
That’s built completely wrong.

There’s no need for hardibacker on the shower floor, or for two coats of Hydroban sandwiching a deck mud shower pan. You do need to have a slope under the single, properly installed layer of waterproofing.

07-20-2019, 09:27 PM
Hi Beck, welcome to the forum :wave:
I’ll put this first...I’m just a DIY guy.
I can’t tell from the pictures, but there should be a slope in the floor to the drain. That won’t in itself cause leaks, but leads to stagnant water pooling.
My first thought at looking at the opened back wall was if the GC puts hardiebacker or a CBU over the studs when closing up the wall and then coats it with Hydroban, how is he planning tie the new wall waterproofing into the already existing wall waterproofing? The areas where there are changes in plane are the most likely areas to fail, especially the lower sections of these.
Hairline cracking grout can be just a cosmetic thing. Large cracks and certainly cracking tiles usually have specific cause. Sure, a smack with a hammer would do it, but you didn’t mention washing up your toolkit in there. If this were mine, I’d want to stand there with the shower sprayer just before he’s ready to tile and hose down those seams for a good half hour and then check for signs of leaks.
I’d wager he’ll say something along the lines of “you can’t do that because it’ll cause the tiles not to stick”, or even better “the tile and grout are what make it waterproof”.
Just go into it with a cautious, doubting eye.

07-20-2019, 10:29 PM
Welcome to the forum, Beck. :)

I think your GC has caused enough damage. No sense in letting him do any more, unless your next door neighbor is Mike Holmes. :D

The waterproofing on a shower floor, or any horizontal surface in a shower such as a bench, niche, curb, or the top of a knee or half wall, is the most critical. If not done properly, the shower will leak, without question.

What your guy has done in no way conforms to any standard in the tile industry, and in fact looks like some method that he made up himself, or got from someone else. No legitimate tile contractor or manufacturer of tile installation products would stand behind what he's done. The only thing you're going to get from him is more damage to your house.

And see these two holes right here?


Those are death to a shower curb. There's only one possible way to drill those holes and not damage the curb, and that's to drill no deeper than the surface of the waterproofing. Once the waterproofing is breached (assuming it was intact to begin with), the water will get into the curb and other places. I'll bet if you put a toothpick in either of those holes, you'll likely find the depth of them exceeds the thickness of the slab on top.

But the whole floor and the mess around the drain, that's not in any way correct and won't work, as you've now found out the hard way.

Hopefully you can work with him to allow you to hire someone competent to install you a new shower. If you can get him to pay for it all, you need to immediately go out and play the lottery cause you're the luckiest person that ever lived. ;)

If he insists on continuing with what he's doing, demand a flood test. Tell him you want the drain plugged and the pan filled with water to the top of the curb for 24 hours. It has to be done before the mud pan is installed. I bet you'll have more water leaking into the ceiling below.

07-21-2019, 06:12 AM
Is my GC competent? No

07-21-2019, 07:27 AM
Most leaks start at the curb or seat. The foot prop in the corner is another place. They are handy but need to be waterproofed correctly. Not sure how they will tie in the new waterproofing to what you now have. I would pull the slab off the curb and make sure the waterproofing continues up and over it. What Kevin said about a flood test, I would demand it.

This installer will teach his helper how to install showers and the cycle continues.

07-21-2019, 07:58 AM
At least the GC is trying. Tell him shower waterproofing technology is advancing and he has a chance to learn and be able to sell more work by becoming knowledgable and finding good tiler's or teaching his crews. Just remember one tiny leak and if wood gets wet it will fail. Maybe not noticeable for 3 years or 8? I don't see how he can say he won't replace the subfloor before he sees it? This is his money out of his pocket, he is trying to lose. Its human nature.

Tool Guy - Kg
07-21-2019, 08:14 AM
If you want additional ammo for this GC, call Hardibacker and explain that they’ve used their product to help form the shower pan floor. And they will tell you that you’ve voided their warranty. Better yet, email them pictures so that they state in writing that you’ve voided their warranty. Handing the GC correspondence from the manufacturer that says he did it incorrectly is more powerful than spoken words.

Installers that void manufacturers’ warranties are not considered competent by the manufacturer’s.

Sorry to see what was done. But given all the mistakes, it’s no wonder it’s leaking.

The others have given you good info, so I’m sorry I’m being redundant on this, but I can’t help from re-commenting: During the “fix”, removing the entire wall substrate (of the wall with foam insulation) all the way into the corners, while leaving the adjacent substrates and tiles makes it 100% impossible to tie the new waterproofing into the old. :bang:

Ugh! Sorry to see the severe lack of industry or manufacturer’s standards being followed here.


07-21-2019, 09:32 AM
If you want additional ammo for this GC, call Hardibacker and explain that they’ve used their product to help form the shower pan floor. And they will tell you that you’ve voided their warranty. Better yet, email them pictures so that they state in writing that you’ve voided their warranty. Handing the GC correspondence from the manufacturer that says he did it incorrectly is more powerful than spoken words. In addition to the manufacturer's recommendations, which always take precedence, you might point your GC toward the ceramic tile industry standards as codified in the ANSI A108 standards. Point specifically to the Appendix of A108.11 (Interior Installation of Cementitious Backer Units) where it says, in part: "3. CBU's (sic)cannot be used on floors that are sloped to a drain." While the Appendix is not an actual part of the National Standards, it's still a supplement to the standards with which the tile contractor should be very familiar.

My opinion; worth price charged.