Shower help needed!

We built a new house 3 years ago with a tile shower. The shower floor tile is small hex tiles, which have been the BIGGEST PAIN. Almost since day 1, the tiles were popping up around the edges. We notified our builder as part of the new home warranty process and they'd send out a tile guy (the same guy every time) who would plunk the tiles back in, add a bunch more grout and call it good. We'd reseal the grout every time and wait several days to use the shower to make sure everything cured. I think this has been "repaired" in this way at least 4 or 5 times at this point, the most recent time being last month. Now today I noticed it is happening AGAIN! A whole ~1 inch section of grout popped up, with a bunch of soft gooey white stuff (mastic maybe)?

The tile guy says this is not a problem with how the shower was constructed or tile was installed-- just says "it happens" with new homes. But it seems suspicious to me that this would happen so much and on a repeated basis.

Any thoughts as to what is going on her?

 

First, it looks like there is grout up against a wall or "other" material.
Grout is never to be used up against a dissimilar material.
Color matched grout should be there because of differential expansion.
Nice picture by the way...is that crumbly material grout" It looks to be a different color, like whiter than the sanded grout.

 

I am not a plumber or a pro and I have never installed tile. However, On Hunker there is an article called “How Much Space Between a Ceramic Tile Floor & a Wall Joint?”. I think it may shed some light on your situation.

 

It sort of sounds like they used mastic on the shower floor. Nobody has a mastic approved for use on the pan of a shower...on the walls, yes, but most pros won't use it.

When they did the repairs, did you notice what product(s) they used?

There are only two materials approved for use on a pan in a shower- epoxy or cement based thin sets. Note, thinset is a method, that includes mastics, so that can be confusing.

Tile popping lose means either movement or the mastic bond has dissolved and softened. Mastic softening isn't unusual on a shower floor, but could also be symptomatic of no preslope for the liner. Plumbing code calls for the waterproofing layer to be sloped and that is NOT the tile. FWIW, sealing doesn't make the grout waterproof. It is designed to give you some time to clean up a spill before it stains things.