If you look at the tile next to it, it appears that the problem is more extensive than that one tile. Is this also a shower?

Yes shower w tub.

The missing tile was slightly loose. There is no sign of mold in the area, just staining on the surface latex caulk. It and the tile to the right of it is leaning out slightly, less than photo suggests. Maybe 1/8" flaired out at bottom. (It is the same for the similar title on the undamaged opposite wall. So it looks like it was installed this way rather than due to swelling.

The backing board behind the tile had originally covered only the top ~0.75" of the tile 1.5" height. The lower bacling board edge has eroded a bit now.

This installation looks like it used a thick hardy board like backing that is 1/4" thick and feels like cement. It does not use a thin cement board backing.

The backboard wall stopped 0.7" from the tub. The tub backwall is flanged upwards and it is taller than the 1" vertical gap showing now. Thus, the hardy like board overlapped it but there was that gap under it.

Where the cement hardy like board erroded upwards 1/4" there is no tar felt sheet or polyethylenne sheet water proof layer seen behind it. If it such waterproof backing was used it is not cut to the length of the backing board or extending longer to layer over the tub flange.

It looks like they set the tile with thinset on the wall and also packed thinset or grout into the recess behind the tile to help support the tile bottom. They also put tile adhesive over it.

Finally the ~1/8" seam at the bottom of the title seam to the tub was latex caulked. Outer caulk cracking only showed up about a week ago, after water leaked in and soaked the thick cement board and moistened the fillet and tub flange area right behind it. The tile piece taken out is 1.4" x 3.2". The gap behind the tile to the wall is about 0.5" deep horizontally max into the recess area where the thick board was missing.

Full "Gut and Redo" needed? This suggestion sounds correct if this was a cement board backer with moisture film barrier backing. If still correct in my case, how many tiles wide and tall to remove? Cut out part of backing board and seal and prep, how? Please explain.

Every single thing needs to come out. All the way back to the moldy and rotten studs behind that mess. Then start over.

Thx, but the caulk only recently failed and I don't think there's rot or mold to any extent back there.

"The problem was caused by water leaking in from thin cracked latex caulk seal (removed now) between the tub and bottom tile." No the problem is there is no waterproofing. The visible cement board should be shimmed out to go past the tub flange to the tub deck not stopping above. The cement board requires water proofing on the surface or poly behind it that would also continue over the tub flange so that any moisture goes to the inside of the tub flange and not into the wall cavity. You have neither. It all needs to come out. If you wait it will cost more. Your choice.

There is a popped out vestibule area with two bay like window view to one side of shower tub, with floor, walls and ceiling all tiled.

<click photo below to expand vertically>

So there's a lot of custom fit tile work here.

<click photo below to expand vertically>

The house was built in 1985. We moved in two years ago and use the shower every day. No hint of damaged showed up until about a week ago starting with bottom caulk showing fine cracks. Only cracked caulk and damage showing on the whole unit is on that bottom caulked area in the one corner. When scraping out the old caulk I detected the loose tile and pryed it out.

Would you remove all the tile in the whole wall and redo the water barrier, cement backboard, and all tile? Or would you redo the bottom foot or so where any mosture behind the tile might try to collect?

The current tub/wall seam is about 3/32" to 3/16" wide max. It looks like it was grouted to the tub, then over caulked with latex caulk, shown here after scraping off.

The tub does not look like a tub for a shower. It appears to be missing a tile flange from the pictures. When you have a tile flange on the top, the tile overlaps the tile flange and leaves a small gap for expansion. There appears to be quite a bit wrong with this installation and I wonder how much water damage has occurred.

gary your question pertaining to sealant at tub required and would this not create a stop to trap water behind is a great question that is hotly debated by tile pro's. I can only provide you with the TCNA answer which is sealant. @ homepro01 the tub flange is clearly visible in the OP's first photo's and the wall board must continue past it not just the tile. Poly would also need to go over the flange behind the wallboard if topical waterproofing is not applied. The horrible grout job alone indicates poor workmanship. If the finish is that bad the more important details underneath are expected to be as bad. Op may have noticed this leak a few days ago but that dark discoloration has been growing for a long time. No professional will touch this without a complete redo. Can you find a hack to apply a temporary band-aid? you betcha. $$ now or $$$$ later.

Much appreciate the comments. The tub is indeed flanged. Hard to get all tbe right photos to show it well. In the worst area to left of the missing tile area, the thick backing board even though erroded overlaps it still. So the strong tub flange extends upwards more than 1" exposed now.

I hear you that to be "warranty worthy" all the tile has to be redone right some day. We do not have any marked damage yet. To put that off awhile I'm still wondering about a temp fix for now and using the other shower. This is a bay window like tub area. Currently EVERYTHING on that wall window area is titled. Should it be tiled at all or the tile replaced with another material, requiring a much larger remodel? This area dries quickly, we remove standing water on the vestibule floor and tub rim after every shower.

And the Cat looks awesome there.

And shows no waterproofing anywhere. But does show plenty of black ick. And there is going to be more.

In 1985, the waterproofing would be behind the cement board in the form of asphalt paper or 6 mil poly. You wouldn’t see it from the front.

Black ick will grow on caulk where soap and skin cells collect. It’s also not indicative of anything.

Obviously, they installed the backer board badly. I always fur it out 1/4” over the flange. You can chisel off the part that sticks out and reinstall the tile.

A little excavation can determine if the asphalt paper is where it should be, if you chose. That makes replacement more difficult but will let you know if it’s going to fail—dramatically and expensively.

The window can be tiled, but when you remodel, swanstone is way more foolproof. And I like foolproof.

Waterproofing behind laps over. No lap over. No waterproofing. Pretty basic and easy to see in the autopsy.

Will consider the exploration excavation for waterbarrier use. How tall are typical tub flanges? Would likely need to go that far plus.

If water barrier is there, the fact it wasn't cut as long as the cement board or longer concerns me ... it suggests it is not there, or at best the back of the cement board was painted with a sealant (is that a historical method?).

It will certainly lap over the flange somewhat but not necessarily longer than the cement board, with such a sloppy installation. If it’s overlapping the flange at all, catastrophic failure at any point is unlikely.

You can’t paint the back of the cement board with sealant. Didn’t exist in 85, and doesn’t work now.

Laticrete #9235 has been around since the early 70's and the first cement board by Paul Dinkle 1970 became Wonderboard shortly after. To answer your question no the back will not be treated. Now you are reaching for the last straws of hope. You need to accept the fact you have a poor tile installation and proceed from there. Your situation is very common. Remove the cover from the control valve and have a look inside the wall. That should give you the answers.

Thx yes was going look around the control valve next. Looks to me that the tile has not been routinely maintained (sealed). So some aging and cracking in grout may have added to the problem.

Been in the house two years with no visible issues with daily use, it looked perfect (e.g. no staining in bottom grout until suddenly now).

This disscussion really makes me wonder about the way tubs are sealed to walls. A Silicon seal acting like a ~1/4" water dike trapping and holding water makes no sense.

Seems to me that there should be a 1/2" gap under the wall backboard with current recommended water barrier behind extended 1/4" further overlapping the tub flange. And their should be engineered a flexible polymer strip to be inserted in the gap to seal between the tub ledge and the tile. It should have antimicrobials in it and be treated annually with an application of antimicrobial treatment. The invention could be a firm microbubble nondegradable polymer.

And it should have a GoreTex film like property, where free water can't get across it, very little moisture is held so it dries quickly, and moisture settling behind the bottom tile can excape as water vapor. Slight permeability to the flexible material and a fused backing of the Goretex oriented towards the flange wall could accomplish this. It could have a thin flap on the back topside so it is installed along with the bottom tile and act as the standard 1/8" spacer below the bottom tile. Being flexible and supported from the back edge it could flex downward if the tub ledge moves downward when weight loaded, still helping block water entry. If the tub settles a little permanently, the permeable membrane would still help block transport water out of the gap.

A spongy expandable sealed bubble like strip material would allow the most water blockage with flexing and also be best at preventing any air gap developing. Just an idea ... on my wish list.

Creative Tile,

Thanks for the correction, did not see the flange on my phone picture but the clipped edges of the cement board.

Gary,

I am highly allergic to Cats but yours is so adorable. Take everyone's advice, it is easy to fix what you have by starting over. Spend some time researching the correct way to do this and you will be able to set an appropriate budget. I am not sure I have any suggestions for your continuing use of the shower. Do you have a second shower you can use in the meantime?

Good luck!

Sophie thx you like to jump to the extreme quickly and make assumptions not always on track. But it's useful to make your point and nudge one towards to the best path. Drama can be fun too.

The invention idea is not for my current attempt to fix. It is in response to thinking about how the seal is dealt with in any new installation. When there's a hot debait about current methods and water pooling anyway, maybe a best approach has not been invented yet.

Removing the faucet flange and I can verify there is no polysheet or asphalt paper behind the cement board. So at some point this all needs to be redone correctly.

Currently I will do a regrout, surface seal, recaulk using a temp fix now for the tile in the flange corner area. I'll use bondo backing for the little tile, which is less tall than the tub flange.

Little discoloration showed on the bottom tile exterior grout until suddenly a week or two ago. I used a tooth brush with 20% bleach and it whitened nicely and then I surface scaped the grout lines to roughen it and remove loose grout.

This is a jetted whirlpool like tub, rarely used. It could work for that in the interim. Daily showers will be in the shower stall in the other bathroom. The tile there looks perfect with no damage. But we will dry it and use a commercial quality tile & grout sealer on it, as soon as the current tub is usuable for a bath.

As we are ready we will plan a remodel and have the tub/shower redone correctly. Like to save up for it.

Please help! I have read all the comments but I cannot replace everything and start over at this time...

I have the same issue as the photo except it is behind a shower liner, not tiles. Is there anything to fill this gap with so the liner is resting on something as opposed to being able to push in.

Can I fill with spray foam? or extra caulking? or need a piece of cement backer board?

TIA!

Pictures may help. I would also recommend when you have the pictures you start a new thread.

Thanks I figured out how to start a new thread... https://www.houzz.com/discussions/5867377/how-to-fill-gap-behind-tub-surround-after-water-damage