Everything I normally write is about building your brand new awesome shower. However, to do that you must first remove the old, outdated, non-awesome shower. There are several ways to do this, I’m gonna show you the easiest.
A lot of people will go in and chip every tile off the wall (don’t laugh, they do it…), then remove the drywall (or what’s left of it) to get down to the studs in order to build the new stuff. You don’t need to do that. It’s time-consuming, messy and will give you a fairly crappy attitude about the project right from the get-go. (Did I just type ‘get-go’??? I need a beer…)
Most existing tiled showers being torn out are ‘builder’s grade’ showers, that means 4×4 or 6×6 tiles with a bullnose tile, normally 2″ wide, along the edges. Chipping each tile off the wall will waste an entire day. So you’re going to remove entire portions of the wall at a time.
The first thing you want to do is chip off the bullnose, or little rounded pieces, along the edges (and top, if you’re not going to the ceiling) of the shower. If you notice in the photo to the right I’ve already done this.
Once you get all the bullnose tile removed you want to take your razor knife and cut all the way through the drywall along the edges of the shower tile. This gives you a fairly straight line for the existing drywall so you can butt your new substrate up to it easily. Normally this will also give you a line directly from the outside corner of the tub, so all your new substrate will sit inside your shower, where you want it.
If you are tiling all the way to the ceiling (which I always recommend) take a straight-edge and place it against the tile along the line you just cut and continue your cut all the way up to the ceiling. This should give you a nice straight line from the tub to the ceiling.
Next, take your crowbar and insert it into the line you just cut. You want to pry the entire tiled portion of the wall off the studs. You may not be able to ‘pry’ it! If there is not a stud directly behind the line you cut, or on one side or the other, you may have to just place the crowbar in there and ‘pull’ the wall off.
If there is not a stud behind that area you’ll need to add one to tie the existing wall to your new substrate. This will describe how to do that: Drywall to backerboard transitions for shower walls.
The drywall is normally put up with either nails or drywall screws. In either case you can pull those right through the back of the drywall when you pry. You’ll need to work it back and forth a little to get it loosened, but it will eventually peel off the studs normally in half-wall or whole-wall sized pieces, like the photo at the right.
Just grab that entire piece and haul it off. You can also bust that piece into smaller pieces by pressing against the back of it (after it’s off the wall) towards the tile where you want it to break. It should fold right over to make more manageable sizes.
Then you can take your razor knife, clean up the edges around your shower and install your new (waterproof) substrate. It’s quicker, cleaner and much easier than trying to remove each individual tile, then removing the drywall. Try to make your project easier from the beginning.
If you are removing it all the way to the ceiling be sure to cut the transition from the wall to the ceiling with your razor knife. It is normally taped and mudded to the ceiling, which means if you don’t you’ll tear the face of the drywall off the ceiling board, requiring repair and repainting. If you cut that transition first it should come off cleanly.
I normally leave the caulk or silicone line in the corners as I’m doing this. The photo where the wall is hanging there – that’s just the silicone holding it up there. It gives you a bit more control and everything doesn’t come crashing down once you get it off the studs. Just grab and peel the wall out of the corner, it’ll come right off.
To remove the back wall you’ll need to create an open spot to grab and pull or pry. Take your hammer and bust out a vertical line of tiles in the middle of the wall so you can get your crowbar behind it. Always remove the side walls first, then the back. That is likely the reverse order they were installed and you won’t run into the drywall being hung up in the corner behind the adjacent piece.
This is the easiest and quickest way I’ve found to remove your old shower walls. Don’t waste time on demolition (unless you’re sadistic like that) when you can better spend that time building the new stuff. It’s still a bit messy – demolition always is, but it’s much less messy to have stacks of drywall with the tile still attached than to have buckets of old broken tile and a pile of old drywall.
This method works with nearly every old wall substrate, including cement backerboard, if you are lucky enough to actually have a shower with backer behind the tile. It’s a bit more messy, and a bit more difficult, but the same technique applies.
And if you’re removing carpet – cut it into manageable strips! I can’t tell you the number of times I’ve seen people tear it out in one large piece, fold it, roll it, wrestle it through the house to get it out, knock stuff over because it’s still six feet wide and weighs 200lbs., knock over more stuff… You aren’t saving it, cut it up!
Or don’t cut it up and send me the video of you trying to get it out of your house – I could use the laugh.
I am about to start a tile project but the tile walls are the plaster over wire mesh kind. — Any tips on how to demo this kind of wall?
I am assuming the floor is same. over tongue and groove.
I watch people on YouTube hammer and chip away. Looks horrifying.
I’ve just got to say, I used a hammer to take out the 4″ x 4″ tiles on my kitchen backsplash and it worked pretty well. I only damaged one piece of sheetrock. Then…due to rotten wood in the bathroom, I had to pull up all the tile on the floor. I just thanked God that the toilet and I didn’t fall through the floor into the family room below! Whew! Again, my tool of choice was a hammer and it worked great…didn’t take much time at all So this girl is all about a hammer for deconstruction!
Good morning. I have one quick question regarding placing the shower liner. We have framed a neo-angle shower utilizing your advice every step of the way (Thank you!). Where the shower is angled, the liner does not lay flat, it bunches. It is ok to let the wrinkles stay in the shower and mud over, or should I cut and patch to get a smooth overlay. If patching, can I use Oatley shower liner adhesive and excess pieces of the liner? Thanks again!
You can cut and patch it, but it’s always better just to fold it as flat as you can get it then be sure to pack the mud tightly against it to ensure there are no voids.
I have a shower that is only 9 years old and from the beginning I think we have had problems with this master shower. The big walk in shower had a built in seat in the corner about 2.5 feet wide and a foot deep. The area under the seat has been leaking water down into the crawl space of the house. The first time we noticed this we found the grout to have cracked in the corner area and along the back of the bench. We resealed the shower and put calking in the corner and along the edges all around the shower. About a month ago I was in the crawl space and yes it was leaking again and I could see that the subfloor was rotting in this area. There is not any pan under the bench at all. The only pan in the shower was directly around the drain. I have removed the bottom 2 rows of 12 x12 in tiles all around the shower, along with the bench seat. I have also remove all the flooring down to the sub floor. Part of the subfloor is needing replaced as well. Interesting enough is that in a new construction house like this, my builder cheapened up and did not put backer board under the tile on the walls. All the tiles are directly on sheet rock. When removing the tile my concern now is how do I create a water tight bond to the dry wall that is not perfectly cut in any manner behind the existing tile on the walls. My original thought was that I would just be able to put backer board up the 2 foot of wall and proceed from there. I have use a cutting knife which provided a relatively clean cut but because we were removing only 2 rows of tiles the drywall in many place broke away unevenly just behind the existing tiles. QUESTION IS what can be done to match up the drywall and new backer board or should I bite the bullet and remove all the tiles and start over?
You CAN use kerdi over the drywall to tie in new waterproofing. The problem with that is your shower will still not be waterproof, water will still get behind your wall tile and into the framing behind the drywall. The shower should be replaced.
Thank you for a seriously clear and sensible description of the strange environment our species needs to contain water in order to cleanse and groom ourselves on a regular basis. This is really golden advice on securing that human practice.
I bring the task of (partial) repair of a tile wall above a tub, all constructed in the 1970s. Folks who lived there for a ferw months had neatly held tiles up in the area of the wall that got the maximum shower spray…with duct tape. I pealed it off, and some dozen tiles fell into my hands and a dozen others were easily removed. and then I pried a bunch more off in all directions. Behind it was two layers of sheetrock that had been bracketed to some kind of flimsey looking metal “studs.” The sheetrock had swelled and crumbled, but no mildew or mold.
So I have deconstructed a hole of about half the wall (the area always hit by the shower spray), and my plan is to frame that hole with 2×4’s, wrap them in tarpaper, and screw two layers of hardibacker to these studs. Clean off the tiles and reapply them.
My main questions are:
Is this a sound plan? The rest of the wall is dry and strong still, after 40-some years. So I’m thinking it’ll last umpteen more years with this repair…
Would putting redgard on the front hardibacker before tiling be a good thing, or a redundant waste of time and money?
Roger, due to a pattern change request BTW I have 8 – 6×6 tiles I need to remove from the topical shower that I am building so it doesn’t look like the afterthought it is. Other than a hammer and a sander any sugestions?
I will be ripping a shower stall out and replacing it. I’m used to replacing an acrylic base and going back with a kerdi drain with a wood subfloor. However, This is in a condo in a highrise which, I’m assuming is going to concrete under there instead of wood. I don’t know what the normal is under there for this situation. PVC coming up or cast iron coming up thru the cement. Also, since I’ll be using a kerdi drain. Do you know what I’m going to find and have to deal with under the acrylic base? I know if it was a regular cast iron fitting coming up thru a tiled base, there’s a kerdi adapter ring which works nice but I don’t know the setup under these acrylic bases. Looking for some of your awesome guidance! Thanks.
Depending on the year it was built it may be either. The cast iron adapter ring works for that, or if it’s pvc or abs you can just cut it to the height needed and install (almost) just like you would over wood.
After two weeks of using our new shower, the marble floor started showing orangish stains. We assumed it was iron and used iron-out multiple times, to no avail. We tested the water – no excessive iron. What could it be? The tiles affected are the ones closest to the drain. Could the shower mud be too thin, and copper be coming up from the pan? We are totally stumped. Is it possible to remove and replace only the floor tiles, leaving the rest of our beautiful shower intact? Any thoughts, suggestions would be welcome.
You have a copper pan? Are your weep holes open? How thin is the mud around the drain? There are orange molds – is the orange on the surface?
Hi! My husband is going to retile our bathroom shower area. It’s a tub but the wall tile only goes halfway up as you’ve shown. We’re planning on doing it the way you’ve shown- my only concern (yes I’m a worry wart), is lead. I’ve read lead can be in older ceramic tile?? What are the risks with this
The dust particles being kicked up as you remove the tile can be inhaled. However (!), unless it’s tile from the 50’s or early 60’s it’s RARE that it would have lead in it. You can get it tested if you want, it’s the only way to tell. And if it does contain lead it would need to be removed by a certified company ($$$$$$).
Well I made him cover the vent and wear a mask just in case but our house was built in 1963 and I’m almost positive this tile wasn’t that old. Hoping anyways lol
Roger: Thanks for your informative website. I’ve found a surprise under the existing shower tile I’m removing in my 1966 ranch style house. The bullnose lays on what looks like drywall. Once I get beyond that I’m finding a concrete backer that extends 1/2 below the surface of the walls above and beside the shower/tub and 1/4 above. I was planning on removing it and replacing it with hardibacker and wasn’t too concerned when I damaged some of it removing some tile. It’s much thicker than the hardibacker I’ve bought to serve as the subsurface. Looks like it’ll be a bear to remove. Can I patch it and use the original subsurface? Must I chisel it out? What alternatives do I have?
If it’s not to badly damaged you can patch it with thinset or wet mud and tile over the original surface.
I’m installing a shower and applied 2 coats of hydro barrier to the durock cement board and I noticed something had got stuck in the membrane. I picked it out and it bubbled a bit. I pulled it a bit and the membrane peels right off the wall like latex paint does sometimes. Is this normal? I’m afraid of installing tile if the membrane is not going to hold onto the substrate. I swept the wall before applying the water proofer. Thanks
It’s normal if you peel it off. The tile (or anything else) will never put that type of stress on the membrane. With tile you’re concerned with the sheer strength. That means unless you can grab the bottom of the membrane and pull it down stripping it off the backer then you have a problem (you won’t be able to to that ).
Hi Roger…I have a basic builders tub shower combo in an alcove with tiling on the three sides. I’d like to remove the tub and replace with a slightly wider, deeper model. Can we remove just a few rows of tile above the tub and then replace with the same or a complimentary tile? Thanks for your great advice!
Yes you can. Depending on your waterproofing method (if it exists) it may be a bit difficult to tie in the waterproofing, but it can be done.
I’m converting a bathtub to a shower and have completed the demo. I replaced the drain in the floor at the level of the slab. I caught my mistake and was able to remove 3/4″ of concrete around drain and sloped up to the slab. The length from the middle of drain to furthest wall is 52″ and to the closest wall is 8 1/2″.
1) Can I still install the pre-slope from here (lower but sloped drain) and does the height of the pre-slope on each wall need to be the same or just use 1/4″ at the closest wall and work out to 1 1/4″ at the far wall?
2) After removing the bathtub, I’m not sure where to put the curb. In the current location vacated by tub or toward toilet by 3″ (making the outside of curb 3″ from where outside tub base was removed). This is a small bathroom, old 30″ bathtub. From center of toilet to outside of tub base was 15″.
1. Yes, you can do it from the lower drain.
2. You can do it either way. If you don’t mind having cut, uneven tiles at the bottom of the walls it doesn’t need to be a level perimeter. It’s an aesthetic thing, it can be done either way.
Wow, I learned so much from you! I have DIY tiled before, but had a couple of unique situations this time – and found the answers I needed here. Your help kept me from wasting time and ensured good results. I was able to cut through the ‘sales pitch’ at the tile store to get the right materials. Good karma to you.
We’re building a shower and considering using a traditional mud and PVC liner pan and topical liquid on the walls. Is that combination acceptable? If so, which book of yours would I buy to walk us through the process? Thanks so much, I really appreciate your advice and the time you spend on making this website available!
Yes, it’s perfectly acceptable. I don’t have a manual available yet for that particular combination, but if you order this one: Topically faced walls and traditional floor shower and just shoot me an email I’ll send you the one with liquid topical waterproofing for walls.
Off subject! Can you direct me to your wisdom on kerdiboard vs the alternatives?
I am currently trying to determine what waterproofing was used on my existing shower wall, and if I will have to redo my entire shower. Pulling up floor tiles, I have found that there does not seem to be any waterproofing at all on the floor. So, I’m doubtful the walls will have any, but is there an easy way for me to find out? I’ve already pulled of the lowest layer of waill tiles, which came off pretty easy.
Another question – the drain in my shower does not seem to be a 2 part drain, just a single piece – would it be in my best interest to replace it?
There was no waterproofing on your shower floor? If not, I can nearly guarantee you there is none on your walls. The only way to determine that is to remove some tile, if there is no waterproofing directly behind that, cut out a piece of the substrate to see if there is behind it.
It depends on what type of drain you do have.
I found your site for the second time while searching whether I needed to mud the back side of 2×2 tile sheets. I wish I’d spent more time here on the first visit. I may not have these questions if I had.
Here’s my scenario. I am installing tile in my shower and behind and beneath a new free standing tub (where the 2x2s go and the floor of shower will go). My brother was here helping me. He has some experience and he switched from mortar to mastic. Now I read here that you say the mastic will get wet and tiles will fall off. Yike! Don’t want that. My first question is; “how likely is that to happen?” My tiles are 18×18 porcelain. Half of them are on the 3.5′ x 3.5′ shower walls for well over a month now. I expect the mastic should be set since it’s not all sealed up with grout, etc and I’m here in sunny hot Calif. I can switch from mastic to mortar for the rest. Home Depot has a bucket of pre-mixed thinset per the label. Will this be acceptable? I am a noob (as in boob motor skills) at this and fear the mixing and setting issues with mortar.
Next question. How porous is grout? I am not terribly concerned about water seeping through the procelain given the .05% porous rating. So if the grout is equal or close to that this lightly used shower should hold up for years. Right? I can and will use the mortar on the shower floor and what remains of the tub underfloor.
If I am convinced that my risk is high and have to remove the half of tiles installed in shower can I do so without destroying them? How? Can I remove the mastic (without water) and use the Duroc that’s already installed? How would I remove the mastic from the back of tiles to create a clean surface for bonding.
I have a plastic backing (waterproof) behind the Duroc and used mortar to seal the taped seams so have not worked with Redguard which led me to this possibly crazy thought; Could I use a baster to squirt Redguard in my grout lines of installed tiles thus adding a level of repelling water to protect my tiles?
Let me finish by saying that I find your style and easy to follow depth of knowledge and instruction simply Awesome.
Mastic is absolutely not acceptable in that application. While the edges are not filled with grout, I can guarantee you that mastic is not cured in the center of the tile. It will cure around the edges, then that seals the inner portion off from the air needed to cure it. You need to remove those tiles and replace them with thinset. NOT ‘premixed’ thinset, that is nothing but mastic with sand in it. It’s a marketing gimmick.
Grout is extremely porous, and you WILL have water behind your tiles. It’s normal. You should be able to just pry those tiles right off without destroying them or the substrate. The redgard thing won’t do anything but make a mess.
First off…you ROCK! Thanks for sharing your knowledge with the world. What started as a simple re-grout of the tiled shower has become a major renovation that we need to do ourselves. Original installation was shoddy (and that’s from a newbie in the high stakes world of waterproofing a shower before tiling). They installed the tile on plain vanilla drywall. Bet if you close your eyes you can see what we found when we removed all the tile and drywall. Yep. A complete mess. We have that part under control. I married a MacGuyver!
Here’s the tricky part we’d appreciate your input on… the floor to wall transition. The floor is tiled and appears to be in good shape, drains well and we’d like to not have to chip it out. There doesn’t appear to be a liner, but there is a concrete pan. We plan on using DensShield as substrate on walls and re-work the curb.
1. Can we bring the DensShield to the concrete pan and seal with silicone to make waterproof?
2. Is this an exercise in futility (not a fan)? If so, what would an Elf like yourself do?
Hi Jerry and Joni,
1. No, you don’t want the dennshield in your pan. It needs to be up off the floor about 1/4″ or so. You don’t want water contacting the board (standing water). Silicone will not fix that.
2. I would remove the floor and rebuild it correctly (waterproofed liner or membrane as needed).
Thanks for the response! We’ve found your books helpful and entertaining…Bonus!
I hired a contractor to retile the tub surround, and I ended up firing him because 1) he didn’t waterproof it, 2) he didn’t tape the joints between the drywall and hardie backer, and 3) he didn’t mortar the hardie backer on the floor in the rest of the bathroom. I now have a semi-finished bathroom- the floor can be saved because all that needs to be done is to unscrew the hardie backer, mortar it down, and then reattach it. The walls are another thing though. At this point is the best thing to do to chip off the tiles so the backer can be unscrewed from the studs and start over? I don’t think he used the mesh tape on the joints either- I found a roll of something that looks like it’s made of paper. Or can I chip the tiles off and paint over the backer with Redgard and then retile?
You can do either. Anything to get the shower substrate waterproof.
I’m about to build a shower enclosure with 2 glass walls at 90 degrees and two tiled walls with 9×36″ porcelain. Traditional deck mud pan with 40mm pic liner.
I’m going to build the curb with bricks. Should I use regular or modified thinset, and can I butt the bricks right next to each other? Also, what size trowel for the thinset?
Also wondering about the different kinds of pvc corner pieces I’ll need for the corner where the curb meets itself and the corners where the curb meets the walls (glass butts up against tile walls running perpendicular)?
Modified thinset and the bricks can be butted to one another. You just need regular inside dam corners for all your corners and one outside dam corner for the outside corner of the curb.
I just started the demolition of my 1970 shower (tile floor and walls). I’m confused by what I am looking at… Around the edge it appears in this order: tile, grout, backerboard, drywall. Yes, the backerboard is sitting on top of drywall. Further investigation beyond the bullnose tiles (and backerboard) shows there is something like cement or mud behind the backerboard, even up at the top. So without backerboard, there would be drywall with a giant rectangle cut out, and some gritty filling… I have yet to see any membrane or other waterproof layer. Do you have any idea what I am looking at? I have tried to follow your method, but it doesn’t make sense when you start adding extra layers. Pulling it down has turned into breaking it down.
I have no idea what you’re looking at either, I can’t see it from here. It sounds like there was a mud wall substrate at some point, with drywall over that, then backer over that (no, there is no logical explanation for that, but there rarely is). At least that’s what I thought, until I read ‘drywall with a giant rectangle cut out’, I have no damn idea what that it. Get rid of all of it and you don’t need to worry about what *was* there.
Life happens, and only recently did I finish removing all the old stuff. It weighed a ton. It took forever, even with sledge hammer and 36″ crow bar employed. It was (rusted) metal lathe with very thick mud. I have also removed the tile and the first (of two?) layers of cement/mud-like stuff from the floor.
I guess all I have left is removing the old drain and the rest of the flooring, which includes more mud-like stuff sitting in a black layer of unknown, no-longer flexible material… I’m not sure how to go about that, but I’m trying to take this one thing at a time. Thanks for your help! I bought a book package, and it will be very helpful once I get the demo done.
I just bought the book and I think its great. I read something and I am confused:
f you run the backer over the flange stop it about 1/8” above the
tub rail (the horizontal part of the tub or base). DO NOT
silicone or otherwise seal that gap! If you do that the water
running down the moisture barrier can not run into the
tub, it will be trapped between the barrier and backerboard.
I was planning to run backer board over the flange but use redguard. Do I need to leave this visible gap? I ask as I don’t think I have ever noticed such a gap in shower and tubs before? I thought i can tile right up to the tub or at least fill that area.
If you use redgard you need to silicone the gap where the backer meets the tub flange. What you want is a continuous surface which water can run down and into the tub. With a barrier behind your backer that open space allows it to do that. With redgard the water is running down the face of the redgard, so you need to have that continuous barrier to the tub flange, that requires the silicone.
If the visible gap you’re speaking of is the weep holes, yes, you need to leave that. I’m not surprised you haven’t seen that gap before, no one knows what the dip at the front of shower bases is for. They are for weep holes. Some tubs have them, some don’t, but you still need a space for water to get from behind your tile into the tub and down into the drain.
Hi! Great info on ditra.
I have a large room and wish to use ditra heat to heat a small section. I would like to juxtapose cement board for rest of room to save cost of putting Ditra across the whole room.Subfloor is 3/4″ plywood over concrete. There is a basement below the concrete floor. Will tile crack at interface?
Not if you put a soft joint over the transition.
Your website is brilliant! Thank you!
Our 6×6 inch white tiled-wall-tiled-floor shower enclosure is leaking onto plywood subfloor (easy water-stain viewing in a generous crawlspace under house) at side of the curb below old aluminum-framed glass door pin-hinge. We have since removed all glass since door pin hinge and hole was denigrating and we had already fixed it 3-4 times over the last 12 years and it was shot (our last fix entailed drilling a new hole into the aluminum frame to insert the pin and then the leak started showing directly below this spot 1 month after that (so we assumed door/curb area was probably the source). We were going to replace door/panel glass after fixing loose grout spots with epoxy-grout but I am now not so sure that is a good idea after reading on your website that tile/grout is never waterproof. There are little 1-3cm missing grout spots throughout the tiles on wall and floor and a few cracks between grout and tile, otherwise the grout is rock hard where intact. White grout lines are mostly 1/16 inch wide with a few areas that are 1/32 or 1/8.
This is a master bath addition done 25 years ago by previous owner but we read on some website that these types of all-tile showers only last about 25years and so maybe everything needs to be replaced since I have no idea if the liner (or whatever waterproofing) at the curb is what ultimately failed and maybe the door was not the problem (correlation does not equal causation: we once ripped out the drywall around a newly installed bath fan when water leaked at the corner of the fan the day after we installed it, but it had nothing to do with the fan, the roof had independently decided to leak right at that exact spot over the fan the day after it was installed…we live in SoCal and it almost never rains…what are the chances!).
To back up…..in order to troubleshoot the problem a month ago before removing glass enclosure, I put silicon caulk (over cracked grout/old caulk after not using the shower for a couple of days to dry it out) around the entire perimeter where tiled wall meets tiled floor extending 6 inches up the wall at the 4 corners and also on the curb (side facing inside of shower) to see if leak would stop; it did not. It was at this point we removed all glass assuming door hinge was source of leak. Yesterday as I was removing loose grout in order to re-grout and prep for a new door/side glass and angled threshold, I pulled off the silicon at one corner where two walls and the floor meet and to my horror about 8 oz of clear water poured out onto the floor and then went down into the drain….and so now I am thinking entire shower enclosure needs to be redone.
Unfortunately our American Standard Whirpool tub (5ftx34inches, they don’t make this width anymore) next to shower has the same tile-surround extended from shower so we would have to replace all that tile too (they don’t make ‘wavy surface’ 6 inch white tiles anymore). If the whirlpool tub fails then the tub hole will need to be resized for a standard 32 or 36 inch wide tub and so I figure it should be replaced too if we are going to be spending all this money on redoing all tile (I priced a new American Standard Whirlpool for $1000 that includes drain but not fixtures and would fit the space well). New frameless shower enclosure is $1500-1900 (installed) and would require a new angled threshold over the currently horizontal curb (separate cost). I like a simple white 3×6 inch subway tile and a white quartz countertop around the tub’s horizontal surface but still need to get quote on this.
I don’t want money to be wasted…….oh it would be so much easier to fix a few broken grout spots and replace glass……but I worry this may not fix the leak if waterproofing under the tiles is the actual problem and then we are out the $1500-1900 spent on the glass enclosure……your opinion?
It sounds to me as if the waterproofing under the tile is the problem. The reason I say that is that when you removed the silicone and water ran out that is indicative that water is running down the wall behind the tile (as it should) but there is something that is letting it into the substrate (your leak). If it were operating properly then the water that drained out would not have been trapped in there. Do you have weep holes in there?
No weep holes anywhere, but your weep hole pics seem to be for tub or shower pan with tile down to it. We have a shower that is tiled everywhere and a tub just on the other side of the glass panel (one removed) of shower enclosure. Does it still need weep holes? If so then before I caulked it weeped almost everywhere around the bottom where wall tile meets floor tile and my recent caulking-as-troubleshooting-method just prevented all weeping there. But it seems that the water should be flowing behind tile and then into the lower weep hole of the drain? If drain-weep is plugged and if curb is not waterproof near the top then that could explain our leak. We had not used the shower for several days before I pulled caulk off and water poured out so definitely not draining.
I am seeing a shower gut job in my future. Thank you so much for your posts. Even if we don’t DIY I like to know what is going on so I can make the right choices and know if the contractor is doing a good job. I am tempted to do the demo and some prep myself to save money but leave the tiling to a pro at epoxy grout.
Is there any way to save the shower floor substrate and mud deck by scraping tile off floor and then just replace the wall substrate and use a liquid waterproofing over it? The shower floor slope is very good and the plywood underneath is in excellent shape. Would your detailed manual on the liquid-waterproofing method mention everything I would need to know about topical waterproofing, special drain install and prepping for an epoxy grout installation? I would do it this way myself since I have medium skills and time to let liquid coats cure. We have a second bathroom.
You may be able to save the floor, and do the walls with liquid. You would need to be positive that the leak wasn’t coming from your shower floor or the curb, though. Otherwise you’re just putting new stuff over something that will fail. If you’re going to redo it I highly suggest redoing all of it.
The water should run from the walls under the shower floor tile into the drain. The fact that it is being retained in the wall is indicative of something being incorrect either at the weep holes or with the wall/floor transition.