Another request from one of my readers, this time concerning weep holes. As you may know I answer every question I’m asked here on my site when I sober up get home from work. I have tried to explain in the comments section several times where to create weep holes in a tub or shower (acrylic base) tile installation and now realize it’s a difficult thing to do with words.
So when Kurt asked me to clarify exactly where they go a stroke of genius hit me! (Yeah, I’m slow sometimes) I have pictures. Well, not exactly pictures of the weep holes themselves, but I can at least let you know where they are.
When you have a tub which does not have specific spaces for a weep hole you need to ‘create’ them in your caulk line. Let me back up here a second and explain what weep holes are and why you need them.
A weep hole is basically an open space which allows moisture that makes its way behind the tile a space from which to dissipate. This is the spot that moisture can run out. When moisture gets behind your tile it will always end up at the bottom of your wall (tile installation). When it gets there it needs some place to go – to get out from behind the tile and into the tub or shower basin. That’s what the weep hole is.
Some tubs, and most acrylic shower basins, have these built into them. There is a spot about 3/4″ long that dips down from the plane of the edge and back up. It’s a dip in the edge of the tub or shower basin. When equipped with these built-in weep holes – DO NOT FILL THEM WITH CAULK! Everyone does that – they are there for a reason and no one seems to know what it is. They are weep holes. If you caulk them in it defeats the purpose of them – that will seal in the moisture.
If the moisture is sealed in behind the tile it has no place to dissipate and will simply sit there. Beyond that, the level of that moisture will continue to build with every use. The moisture cannot dissipate at the same rate that is gets back there. That’s gonna lead to a problem. You need weep holes to eliminate the moisture.
When you caulk or silicone the change of plane between the tile and tub you should leave an open space – a space without caulk – in each side wall about an inch out from the back wall. If you click on that little bitty picture to the right you will see two pretty pink lines on it – that’s where those spots are.
Each of these spots are about an inch long (this doesn’t need to be exact) and contain no grout, caulk or silicone – they are simply open space. These are your weep holes.
These spaces will allow moisture to dissipate. These do not need to be the lowest spots on the tub. In other words, if your tub is not entirely level and those spots are not the lowest, it doesn’t matter. The water will end up there and run out – it is the only space to release the pressure the water will build up. It’s a whole physics thing and I haven’t had enough beer Pepsi to properly explain it – but that’s what happens. And yes, you can put them wherever you want, that’s simply where I put them.
When you have an acrylic or fiberglass shower basin without built-in weep holes the same technique applies. Depending on how your tile and shower door lay out you may choose to put the weep holes toward the front of the basin, entirely up to you.
If you click the photo of the shower to the right, and ignore the fuzzy toilet seat cover, you will see the two pretty pink lines in the back as well as pretty blue lines toward the front. That’s where I put them when I don’t put them in the back. They sometimes look better toward the front if there is a shower door there – the frame will make the weep holes less noticeable.
That’s it – longer than I expected but much easier than trying to explain with just words. If you have a question or just need something clarified do not hesitate to let me know! My blog is here to help you and the fact that I do this stuff every day will, at times, blind me to certain basic things. I do a lot of this stuff without even thinking about it and don’t realize that what is basic to me is not basic to you. If you want a post about a specific subject just let me know in the comment section of any of my posts or shoot me an email at Roger@FloorElf.com. Or, you know, send up smoke signals from your dogs back – he may have just burst into flames again.
There you go Kurt, tell mom you win this one and she owes you a six-pack.
UPDATE: I finally got off my ass and actually took some photos of weep holes in the silicone bead around a tub. These are what I’ve described above and can be used in either a tub or a shower base. There is one on each side of the tub towards the front.
Great website. I just found this thread and I have a lot of questions but I’m going to check the site before I bug ya. You’ve probably answered them already. Anyway I thought you and you readers might find this interesting. The house I live in has had shower leaks for years. Definitely no weep holes unless tiles falling off or my eye sockets count. The homeowner attempted to repair cracked and missing grout as well as loose/bulging tiles with glue, wood filler and grout over grout. It seemed comical at the time so I took pics after the “repairs” and again a day or two later. Needless to say the foolish quick fixes didn’t work. There was an obvious leak in the walls and I figured it probably created some mold. So when I bought this money pit recently I knew I had to start there. What I found when I gutted the walls was quite a shock. The mold was so bad it looked like someone spayed shaving cream on the walls. The wood was so rotten I was able to use one finger and push through parts of the framing for the tub/shower and even the exterior sheathing. I touched one piece and it was soft like a sponge and left brown water drops on my finger. Two of the three walls as well as the floor were completely rotted and I believe the tub would’ve dropped right through the floor one day. (That would’ve sucked) The shower was in the corner of the house and I had to gut everything. Two exterior walls, the entire sub-floor, the roof, everything. The entire corner of the house had to go.
I guess the point is that it’s important to build the shower correctly the first time and it’s great that you’re helping people do that. If you (not YOU Roger) suspect trouble in your shower you’re probably right and you need to address it before it spreads and becomes a much bigger problem like the one I’m dealing with. In this case the previous homeowner was very stubborn, always right and I didn’t have much knowledge about this stuff so I didn’t attempt to help fix this bathroom until it became my problem.(not that breathing in the mold wasn’t already my problem;(
Well, that’s-ma story Roger. I have lots of pics if your interested or want to share them with your readers to show a good example of the dangers of waiting too long and not doing the job right. Later, John
Remodeling a Bathroom is a challenge at this point with waterproofing. comments have helped.
This UNMODIFIED tinset does not stick to kerdi membrane. HELP!
I’ll need a tiny bit more info to help you out. What particular unmodified to you have? What do you mean by ‘does not stick’? It doesn’t stick to it while it’s wet (technically), but after it’s cured it should hold it just fine. What’s going on with your installation?
I cannot leave this sight. Awesome!!
We have a 20 year old shower that has tiled walls and floor. Roughly five years ago we noticed oozing in a few places along the grout line where the walls and floor meet, which left a trial of lye. We also notice a few places on the wall where the grout eroded. Since we had no issues before this event, we assumed the missing grout was the culprit. Two years ago we had the grout removed and replaced with an adhesive grout. Unfortunately, the seeping at the wall/floor seem has returned. Here is some history/questions that we’re hoping will help you provide some advice:
1. Best I can remember, the floor was built with a cement foundation and a vapor barrier that folded about 2′ up the wall. It seems that’s now acting like a giant swimming pool under the tile. The drain is cast-iron with three weep holes. The tile is Kohler ceramic, and grout is Standard Series, Polyblend, Non-sanded grout
2. I’ve been under the house and there is no sign of leaking below. It’s quite dry.
3. We cleaned the drain weep holes about once a year. The first few cleanings after the seeping started, there was noticeable draining out the holes, but not now. I use a coat hanger and grabber screw for clearing. However, they only penetrate about 1/2 inch in. Should they go farther? If so, do you think the holes are blocked?
4. When the re-grout was done, they put a de-humidifier in the bathroom for two weeks before their moister detector indicated an acceptable dry level.
5. What should we do?
– Remove the tile and re-drill the weep holes? (Really don’t want to hear yes to this question.)
– Get the grout guy back to make weep hole cuts at the wall/floor seem? (So far, he isn’t answering calls.)
– Tear it all out and start over? (Absolutely don’t want to hear yes to this option.)
– Or what???
Thank you kindly for any tips.
It sounds like your weep holes are clogged. Cutting weep holes in the wall/floor transition will do nothing to alleviate the water trapped beneath your floor tile. You will eventually begin to have many more problems there. The only thing that should eliminate the issue is to remove the tile around the drain and repair whatever is causing the weep holes to plug up.
Thanks Roger. We appreciate your input. It appears to be a pay now, or pay later situation. We’ll now be entering the contractor black-hole…
I noticed in your diagrams of where you put the weep holes (the ones with the pretty pink [or blue] lines) that you only put weep holes on the two end walls – the head and toe of the tub. What about the back/side wall? Doesn’t it require a weep hole as well?
Also, I think I need to go cut some weep holes in my current tub/tile surround – the previous owners were *definitely* caulk-crazy!
The arm of tubs is manufactured so that, when properly leveled, the water drains to the outside corners of the tub from the back wall. So they are not required in the back wall, but you can put some there is you want to – it won’t hurt anything.
I assume that tubs have been manufactured this way since my place was built (1984, the tub is original – and awful!!! Well… not really, I just want to replace it cause it looks dingy. And the caulking… oh the caulking… I have pictures of the caulking in my bathroom that rival some of your “flawed” pictures. :eek:) and that recutting weep holes will tide me over until I can afford my new shower?
Also, FYI, I received the email giving me the links to your free shower waterproofing manual, but I didn’t receive an email notification that you had responded to my comment here, either in my inbox, or my junk mail. I had posted a comment regarding double moisture/vapor barriers (which I think I have since figured out but have an additional question regarding) but I can’t find the article I made the comment on to see if you’ve replied!
Yes, it should last plenty long enough. As long as water can get out of the wall into the tub where it belongs your shower is functioning correctly. Sorry, can’t do anything about the poor workmanship on the caulking.
Sorry to keep harping on this, but I cut the weep holes last night and realized the vast extent of the caulking – it appears as though the previous owners caulked EVERY GROUT LINE of the tile surround! A 30×60 tub surround to +76″ made with 3×3 tiles!
Should I go through a scrape all the caulk out down to the grout or is cutting weep holes going to be sufficient for drainage?
Weep holes should be sufficient. Actually, replacing the shower would be more efficient.
Weep holes cut for $0 versus an all new shower enclosure for $$$$…
I’ll stick with the weep holes for now.
Unless you’re offering to come to Oregon and build me a free tile shower? I’ll let you think that one over.
In the meantime, thanks for the advice!
Ummm, I’ll check with my wife. I have a feeling you may be on your own, though. Sorry.
Roger : Patterned concrete slab on grade, radiant hot water. 3′ x5′ shower, tiled stud walls, 6 mil vapour barrier, cement bd. 5′ Linear drain with end outlet, cast in place, under shower doors. Shower and bathroom floors sloped to drain. Topical [redgard] under shower tile and 2 ‘ of bath. How do join topical to linear ? Murray
Paint a continuous layer from the existing redgard on the shower floor and bathroom floor onto the horizontal flange of the linear drain.
Just the facts ma’am! Thanks for that.
I just completed a deck mud pan (with your help) and now have a KBRS tile ready pan that I’m installing in place of a tub in another bathroom. KBRS says to fill the drain weep holes with motar as they are obsolete when you use their pan. That doesn’t seem to make sense from all I have learned from you.
The kbrs pans are essentially a topical waterproofing, nothing gets below them as it would in a top mud deck where a weep system is necessary. Since the weep holes would sit below the pan they should not be open, all the water goes into the top of the drain.
I have been reading through your website and have come up with answers to many questions.
One thing that I need/want clarification on: Our shower has tiled walls and acrylic base. There is anywhere beetween 1/16 and 1/2″ of space, between the pan and the wall tile. Grouting the space won’t work because there is too much movement in the pan. This then becomes a situtation where caulking the space is the best answer, correct?
Thank you for your time.
Yes, but it’ll look like hell. Is there any way to replace the bottom row of tiles with properly cut ones?
That would be great, but with the history of this house, it would turn into a total bathroom remodel (a repair attempt in our other bathroom, turned into that issue) and we can’t afford it.
We have left the space open, because it didn’t bother us that much and hey, water doesn’t build up in that space that way, but it likes to grow pink mold and the smaller space is not easy to clean.
You can get some backer rod (it’s foam rod) and stuff that in there, then go over it with silicone. It’s made to fill excess space behind silicone, you can find it at any big box or hardware store.
I am so glad to have found this blog! I have been trying to figure out our weep hole problem. I am a complete beginner to home repair. Water has damaged the wall next to our shower stall door. I believe I have researched enough to be able to patch up the damage to the drywall. But I am trying to trouble shoot the underlying issue from the cause of the leak into the wall. The weep holes in the shower have not been caulk ed over. I have cleaned them out so there is no blockage. What I can’t tell is where the water from the base tray is going into the weep hole and back into the shower. Should there be an opening somewhere between the shower stall (its one of those acrylic wall showers)and base tray? It looks like everything was sealed with a clear silicone. The one weep hole on the opposite side of the door jam appears to have a small opening about the width of a finger nail on the outside of the shower door, unless that spot was just missed by the builder. Should I scrape off all the clear caulk and run the shower to see if I can follow a water trail before I patch up the wall? Or am I better off just calling in a professional before I do more damage. Thanks for any assistance.
With acrylic shower wall systems the only weep holes are in the shower door frames. The walls do not need a weep system because it is a waterproof container. My guess would be that the sealant has failed somewhere in the shower.
I have a tile shower with a base with pre casted weep holes in the front by the shower door on both sides. This is new construction. The weep holes are cover with grout where the tile meets the base. Then they filled them in with silicone. They did not set the base in mud. The just screwed it to the floor. I don’t think they used a bladder, just a fiber board. I took the shower door apart, because water was leaking into the wall and trim. I removed all the caulking and water was trapped behind it. The shower door frame had a lot of silicone jammed in the corners where the base, and side frames meet. Is this correct. I would think you would want these clear so the water can run back in the shower. The other question is should reinstall the shower door, and, dig all the grout out off the weep holes, or should I just re do the whole thing since it was not installed right.
I would redo all of it. But if you want to just do the basics you need to scrape everything out of the weep holes and leave them open, and all those channels at the bottom of the shower door are supposed to be left open as a weep system.
This site is very informative and helpful. I’m having a weep hole problem with my acrylic shower basin. Water is actually splashing up through the weep hole and then running down the edge of the tile to the outside where it has damaged the base board and started to damage the floor/ceiling below it.
Any thoughts on how to prevent water from splashing up the weep hole and then into my wall?
Thanks in advance.
Is your weephole located as it is in the above photos? If so – what edge of the tile is it ‘running down’? I’m not quite understanding what you’re describing. It sounds to me as if the weep hole were not there it would simply run down your tub or base arm. I’m not getting it. (not unusual )
I will tell you that water will not splash ‘into’ the weep hole – there is constant negative hydrostatic pressure pushing from the inside of it (behind the tile) out – water can not get into it.
I am replacing my shower floor basin with a newer one. When I removed my old one, I noticed it was installed right over the plywood subloor with nothing in between. Is this the correct way to put my new one in?
If you’re talking about an acrylic pan then no – it should have mortar beneath it to support it. That’s why shower bases and tubs squeak when you step into them – they are installed incorrectly.
I have a 4 foot shower with tiled walls and a shower pan with weep holes. It is in new construction, about 4 years old. The weep holes are not caulked. Problem is that I have had to replace the caulking about once per year. The caulking gets very black, especially at the base of the shower head. I use silicone caulking for bathrooms. What causes this recurring mold on the caulking? What is the best caulking to use?
It’s not the caulk or silicone, it’s water management. Water is being trapped behind the silicone. Reading the article above and applying it should solve the problem.
hi roger. i am putting in a surround shower with an onyx shower pan and i have a problem with the corner of the pan sticking out under the backerboard by about a 1/16. on the rest of the walls the backerboard extends past the rim of the pan about 1/8″.(the flange?) i am going to use aqua defense over the backerboard.
1. can i remedy this corner when i mud and tape ? yes this corner is off, not square, but just down low where it sets on top of the flange. i am assuming that the backerboard should extend past this rim for drainage and so the tile will extend past it without touching the shower pan.
2. if the 1/8 gap between the pan and backerboard is to be filled with silicone, and it only lasts 5-7 years, how will i remove it and redo with the tile in front of it. also have been reading that new silicone wont stick to the old silicone residue. is it possible to put a strip of kerdi over this gap so i don’t have to worry about it.
3. i hope i am safely assuming that the tile is started aabout what, 1/4 above the curb, so could i caulk a whole bunch in there, and leave weep holes and not worry about it…?
4. oh, and i have been reading that silicone does not stick well to onyx, is this true ?
5. i have a window on the outside wall, do i silicone between the backerboard and vinyl and then caulk this 1/8 gap with caulk when i am finished tiling..
6. oh and another thing, now that all the backerboard is up………should i have four corners meeting .in the corners?……cant on the floor, cant find where it is wrong to do on the walls…please say its okay
thank you for your help……im going nuts……and bald from pullin my hair out…..
I think I’ve already answered some of your questions.
3. I begin about 1/16″ between the base and the first row. Silicone and weep holes.
4. Silicone sticks just fine to onyx if properly installed.
6. It’s fine.
Sorry for the delayed response, my spam filter went ape shit last week for some reason, I just found your comment in the spam folder, I hope the answer found you in time.
Great information! I’ve been looking forever for an explanation of the problem of water building up behind the tiles and being trapped by the caulk. Why are there not weep holes on the third wall of the shower, though?
There can be if you want. The idea is to keep them behind the door or curtain at the edges so they aren’t so noticeable. And everything (is supposed to) slopes to the outside edges. You can put them wherever you want, though.
Roger, Are weep holes needed in a kerdi shower. Deck mud shower base but no liner, using kerdi everywhere and kerdi drain, just not their styrofoam bases, curb or benches. I’m using cement board everywhere and I have a wood subfloor. I’m using Epoxy grout everywhere. You make no mention in the PDF manual on Waterproofed Floor and Walls with Schluter Kerdi. Should there be? If so how do I go about doing this.
No need for weep holes in a schluter system.
Roger, I have just about all your manuals and I think I have come a long way. After completing my master bathroom (complete gut to studs, joist, truses: wall, floor, ceiling), I have started on the hall bathroom (complete gut). I noticed that during the demo, the walls in the bathtub (1976 drywall) the blue 4×4 inch ceramic tiles were glued on the wall (huh, was that standard back in 1976?). I did tear out the wall in just about wall size sections like you said to do and it was easy.. Anyway, my question are:
1. Can I use epoxy grout instead of 100% silicone where the bathtub and tile meet?
2. If not, why not?
3. If so, Do I have to put weep holes?
4. Can I put weep holes in epoxy grout if allowed to use epoxy grout there?
I’m using Laticrete SPECTRALOCK PRO Premium Grout everywhere and I like to use it at the bathtub tile corner.
Here is a weird question:
Can I use both epoxy grout and silicone (one on top of the other)?
About the hall bathroom: Hardibacker Cement board everywhere, Kerdi only on the walls in the bathtub, redguard everywhere, even over the kerdi. I did silicone the behind the kerdi where it met the bathtub lip per your manual. My bathroom progress photos can be viewed at:
1. Yes you can, but it won’t last, so no.
2. Because the tile and the tub will expand and contract at different rates. While epoxy is nearly bulletproof, it is brittle, it won’t withstand that and will either become unbonded, crack the tile, or crack the tub.
3. Yes, but you can’t do that, so no, don’t worry about weep holes.
4. Yes, if you were allowed to use epoxy there.
Yes, you can use both, but why would you? Just use silicone.
I like the new stuff a WHOLE LOT better than the blue stuff!
Long before I saw this blog I caulked a tub line. It did not have built in weep holes and I did not leave the weep holes. Does it make sense to cut out the weepholes now using a utility knife or do I need a special tool that bends behind the tile? I don’t want to damage my vapor barrier overlap at this point…what to do?
Just cut some weep holes out of the bead. Water will find it.
I’m remodeling and putting in a tile shower using an onyxcollection shower base, a plastic vapor barrier on the studs, hardibacker and Porcelain tile. I have done a lot of research online and was also wondering about the need for a weep hole. Thanks for clarifying the need for it. I am also of the understanding that I need to silicone the space (about 1/4″) between the backer board and the shower base. Should I also then put weep holes in that layer of silicone as well? Otherwise water could not make to the weep holes in the silicone bead between the shower base and the tile. Thanks for any advise you have on this!
I know they say to silicone the backer to the base – do not do that. They say that because everyone assumes the backer is waterproof, they don’t know anything about the barrier and water management behind it. Just make sure you silicone the back of the barrier to the base.
Your website is only website that I see discuss the weep holes in tubs and showers. One time I asked the guys at Home Depot and they had no clue.
The need for weep holes makes sense but what prevents water from getting into the weep holes while showering? I presume all water that leaks through the tile seams is designed to end up going to the weep hole.
The real problem I am having is that shower water has been seeping to the floor trim just outside the aluminum shower door. The trim is also next the weep hole that you describe. The trim has also become moldy as a result.
I need your help.
Negative hydrostatic pressure prevents water from running into the weep hole. More water behind it than in front of it, and the water in front of it isn’t being pushed, the water behind it is. Not quite understanding the weep hole / aluminum shower door thing. Is the weep hole on the outside of the frame? If not then the aluminum frame should also have weep holes that need to be left open. They are just little holes drilled into the base piece that everyone silicones over. If they are not open water will fill up in it and may run outside the shower.
In my walk-in shower, the weep hole is next to the bottom corner of the aluminum door frame near the floor. Water under hydrostatic pressure had been finding its way and leaking to the outside of the shower at this corner through the tile. Mold has built up on the floor wood trim. Paint on the wood trim peeled off. I replaced this short piece of trim as it looked very ugly.
Following your advice, I cleaned out the weep hole and now the water leaks into the tub as it should. It no longer leaks to the outside of this bottom corner and no longer ruins the floor trim. The weep hole is now doing its job properly. Thank you!!!
I still have 2 questions. Does not the water that gets behind the tile during showering ruin the supposedly water proof board behind the tile? Is there a minute drain line along the perimeter of the shower base tub to allow the leaked out water to collect at the weep hole?
Thank you again.
No, it doesn’t ruin the waterproof board. It’s waterproof, water won’t do anything to it.
Some base perimeters have built-in channels, but most don’t. Water always takes the easiest path, an open weep hole is exactly that. Water will find it.
Working on a Kohler Ballast shower base that does not seem to have weep holes designed into it and yet their installation instructions say to caulk the entire tile/base edge.
Water is evil so I’m thinking I should leave some weep holes but maybe I’m missing something.
You aren’t missing anything, they just don’t have them on there. Most manufacturers don’t – they aren’t responsible for the wall substrate. You need to leave weep holes.
In reading your blog (I’m doing some re-grouting and caulking), I became concerned about whether our weep holes were blocked esp. since we seem to have build up on the shower floor and in the toilets even with a water softener. So…. I removed the drain cover in our shower. Ugh! There are all kinds of deposits and in feeling around under there where I think the weep holes might be, there don’t seem to be any holes. There might be some places that feel like they should be holes, but they must be blocked. This is a PVC and I looked at a few pictures to try to imagine the weep holes. How do I clean/check this? If I poke around under there, will I damage anything? Or can I somehow remove the top part of the drain? In cleaning out the caulk joints, I found some spots (which were also quite mildewed) where the mud? behind seems to be quite wet. The only other evidence that the weep holes are blocked might be ants (we nuked them this summer so no more ants) coming out from a loose tile on the outside of the shower sill, but maybe we’re just lucky so far in terms of further damage. Do you have any pictures of gnarly weep holes? Thanks,
I don’t have any pictures of that as I usually just trash everything in the shower and start over. You can poke around inside the drain all you want, you won’t hurt anything. The only way to ensure they are open is to remove the barrel of the drain (the part that unscrews), remove tile from around the drain and remove the top flange of the drain – the part held down by bolts. You can then clean them out or whatever you need at that point.
I HAVE A QUESTION, I AM PLANING ON TILING MY SHOWER AND I WAS LOOKING AT YOUTUBE, ADN I NOTICED THAT AFTER THEY PUT ON THE SHOWER LINER CLOSE TO THE DRAIN PEOPLE ARE ADDING PEPPLES OR ROCK THE CEMENT ON TOP OF THEM, I GUESS THEY ARE A SORT OF WEEP HOLE SYSTEM, BUT WOULDN’T THE CONTRETE SEAL THIS UP, WHAT IS THE PURPOSE OF THIS?? THANK YOU FOR YOUR RESPONSE
It is to prevent deck mud from plugging the weep holes. If you use concrete then yes, it would plug them, but a shower floor is not fabricated from just concrete, it’s deck mud.
Are weep holes needed in a shower with a tiled base (on mortar), i.e. not acrylic or fiberglass? Thanks.
Yes, they are needed, but not in the same manner. Weeping systems are built into shower floors and all the water runs behind the tile into the drain, you do not need any place for it to get out, the drain does that.
when you are transitioning from mud bed to the ditra ( walkin shower to main floor ) how do you waterproof this connection.
It depends on how you are waterproofing your shower floor. If you are using kerdi then you just run it three inches out onto the ditra. Ditra is waterproof, it’s just the seams that aren’t. It can be made waterproof with kerdi.
I’ve been concerned with the whole silicone at the change in plane issue at the tub/Kerdi intersection on my current project, and I am glad to see that someone has addressed it. But after having gone nuts making sure every joint is exactly 1/8″, etc, I am bothered by the open weep hole (obviously will put one in, but just not all that happy with the aesthetics). So, just a thought – and likely not a good one. What if instead of using a 1″ open slot, you stuck a strip of white scrubby pad (thickness to equal the grout line)? Those pads are anti-fungal, the piece itself could be situated such that it would slide out to be replaceable, and for us CDO people (OCD in proper order), they could be color dyed with readily available cloth/carpet dyes for nylon. Tonight I tested a strip cut to 1/8″ thickness, 1″ width by 9/16″ deep for my tub surround project. Water runs right through it, with virtually no apparent resistance. I’ll be testing the whole dye theory tomorrow, but quite frankly it already looks less noticeable than an open slot. Thoughts?
Don’t see any reason why that wouldn’t work. Let me know how it works our.