Repair for a Shower floor

[Dradam]

Photos attached: There seems to be a fault through my shower floor and separation of the grout along those lines. Closest to the wall I know some water accumulates under delaminating tiles. I have cleaned off the "fault" line with CLR. Hoping to find a fix with out removing the entire floor.
I want to :
Fill underneath the tiles, but Items such as "fix a floor" are not for wet areas. I was thinking of trying to inject self leveling concrete under the tile ?
Is there any way to prep under the tile- to at least give some chance for the mortar to adhere? --I suspect there is mold- rinse a few times with bleach and then let it dry ?
Regrout with a flexible grout.

Yes, I suspect this may only buy me some time before the floor has to come up, but if any one has had success I would appreciate suggestions. Thank you

 

[WorthFlorida]

Your are trying to patch floor movement and it won't last. "Buy me some time" can be years for some. Is it concrete or a wood floor? If it is a wood floor, what is below it?

If you chip all the old grout out down as far as you can go. Then lay down a very thin layer of siliconized latex caulking deep into the joint and immediately grout over it. Using 100% silicone, the grout won't stick to it. If you see the crack in the concrete fill it up as much as possible with the caulking.

 

[Sponsor]

 

[Dradam]

Thanks for your reply. Pan was hand done 15 years ago. Plywood floor over joists. Not sure if there was a cementboard laid first- but I doubt it. Complete rubber membrane clamped to drain. Dry packed mud pan, thinset, tile.
I can see the bottom of the drain from underneath- I see no sign of cement board above the plywood but visibility is limited. below the shower is my garage.

 

[WorthFlorida]

There must be a lot of expansion and contraction of the plywood between seasons or too much bounce in the floor joist. When you get to remodel, use a floor pan over the wood unless you can really stiffen the floor.

 

[Reach4]

"Flexible grout"? I have never used it, but try that as a search term. Sounds useful.

I would also consider Self-leveling concrete polyurethane crack sealant after removing the grout in that cracked stretch. Those products tend to be gray.

 

[WorthFlorida]

I've seen it at HD but never used it. It's siliconized caulking with sand in it to make it look like grout.


https://www.homedepot.com/p/Custom-Building-Products-Polyblend-382-Bone-10-5-oz-Sanded-Ceramic-Tile-Caulk-PC38210S/100678065

 

[Dradam]

Thank you for these great suggestions, I like the idea of the self leveling crack sealent. I was planning to use simple grout brand as it is a flexible grout. "worth florida" recommended siliconized latex sealant so that the new grout would stick to it. Does anyone have any idea if flexible grout would be able to adhere to self leveling polyurethane crack sealant? I like the idea of a deep sealent that is self leveling-- I think it might have the best chance of flowing under the delaminated tiles. Many thanks,

 

[Reach4]

I like the idea of a deep sealent that is self leveling-- I think it might have the best chance of flowing under the delaminated tiles.

I think these polyurethane sealants are mostly slow curing, so in this case, I would think slow is better if you have the time to wait.

I would mask the tile, and then peel the tape off before the sealant cures.

 

[Jadnashua]

If I understood what you indicated, your liner is on the flat floor, then deckmud, then the thinset and tile. Well, that does not meet industry standards OR the plumbing code. Neither tile nor grout is considered the waterproofing in a shower...it is the liner, so you need a preslope, then the liner, more deck mud, then the thinset and tile. Water WILL get beneath the tile, so to keep it from accumulating, it needs the liner to be sloped so it flows to the drain, assuming the weepholes were kept from getting clogged. Otherwise, the whole mudbed will become saturated. That should not cause the tile to come loose unless they used a mastic rather than a cement-based product to bond then, though.

So, if things are getting loose, it sounds to me like something is leaking, allowing movement, and tile does not really like movement. I think you'll be looking at rebuilding the shower, and maybe fixing some water damage. Hope I'm wrong.

To regrout, industry standards call for removing at least 2/3'rds of the depth of the grout before trying to add fresh stuff in there. That's enough depth to ensure it will bond well and be stable.

Are there any signs of moisture outside of the shower? How about in facing rooms? Tile just don't become loose unless there's some other problems.

 

[Dradam]

Thank you,
I think the bed was sloped but it was 15 years ago. No moisture outside the shower--yet

 

[Jadnashua]

It is required that the top layer of your shower pan be sloped, but the important part is more having the liner sloped, since it is the actual waterproofing. The vast majority of the moisture flows on top of the tile directly into the drain, but some small portion will get beneath that layer and seep down into the mud bed to the waterproofing layer. Having the liner flat means that it will always have some moisture in it that can't get out, keeping things damp. That does not mean that it will leak, though. It will tend to keep things damp, and often, after awhile, start to smell and make it easier for mold to grow.

So, you start with a sloped mud bed. Put the liner on top of it, which is obviously going to be sloped. Then, you put a constant thickness layer on top of the liner, which, because what's underneath it is sloped, will be, too.