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.
I watched a lot of videos before I found out what this was….thank you. So how do you prevent the moisture from the weep holes from causing mold back behind the caulking?
In another shower I probably unknowingly covered the weep holes. If I don’t see any, do I create them?
Mold behind what caulking? There should be NO caulking around your drain. The only exception to that is the bead of SILICONE beneath the liner between the liner and bottom flange.
If it is a three-piece clamping drain it has week holes incorporated into the top flange. The may be in the sides or the top, but they are there. They are always ABOVE the liner, that’s how they work.
The silicone is under the liner to prevent water from seeping up under the waterproofing. Mold also requires air to grow, there is none there when properly installed.
I have an acrylic shower basin with very small weep holes. The builder when covered 90% of the weep hole with caulking. I cleared the caulking and the weep hole is filled with grout. Is removing the grout at the weep hole to the back of the flange of the basin sufficient or should I go ahead and remove the tile where the weep holes are and clean it up behind the tile? Is the flange supposed to be clean of thinset or can it be covered to set the tile?
Cleaning out the grout will be sufficient. There shouldn’t be thinset over the flange, but it won’t hurt anything. I simply won’t bond long-term, so it does absolutely nothing but take up space.
Would the use of weep holes apply for a mud shower bed with travertine floor and walls?
The weep system is incorporated into the shower basin. Either through weep holes in the drain, or over the topical membrane into the top of the drain. Depends on which system you have, but this method is not necessary if properly built.
I have a shower only. Typical 40 ml liner then durock, redguarded up to the ceiling. Do I add the weepholes at the bast of the walls in that shower only setup as well? If so, how many? two for each wall at the ends?
No, the weep system is incorporated into your drain.
And yes, I realize this reply is likely too late, but the info will be here for others in the future. Sorry for the delay.
I’m in the process of re caulking my upstairs walk in shower with a built in bench.
I am trying to figure out where to locate the weep holes since we’ve discovered that we have a leak in our ceiling below the shower.
Is it necessary for weep holes considering the ceiling leak?
What about weep holes that are positioned vertically vs horizontally?
How IN THE WORLD is that a hole for water to go from where water shouldn’t be (inside the wall) to where it already is? In other words, this just seems like a way to flood the inside of the wall or soak the backerboard, or the ceiling downstairs. What keeps shower water from pouring through that weep hole to the back side?
Negative hydrostatic pressure. The pressure of the water behind the wall is always exactly that – pressure. It will always win when pulled down by gravity against a force that is not under pressure (the inside of the shower). Also, if the shower is properly waterproofed – as it should be – you can take a hose and place it right up to that hole, turn the water on full blast and water will STILL not get into your wall cavity. To ‘pour’ through a hole that size there would have to be absolutely nothing on the other side of it, space for the water to go. That doesn’t exist.
If you don’t want to do it, don’t do it. But it works and it’s necessary.
Hi again…. i know i have many questions but i want to do it right …. my tileredi pan that is wonderfully bonded to concrete floor with ultaflex2 thanks to you doesnt have weepholes , is it requested ??? I could nt find rediflash here in canada but the plumbing shop sold me a aluminum T that should go behind base wall and backer board screwed to 2×4’s … should i install that or just sit backer board on pan wall with a beed of silicone??? Do i put weep holes and if so at what height ???, thanks a lot for your precious advise and time !!! Cheers
Here is the aluminum T … if i do install it … is the curvy part goes to bottom or top ??? I think it should face down so water goes to the pan 🤔
It faces down.
The aluminum T works very well. No weep holes are needed in the pan, you need them in your silicone bead between the tile and pan.
Hey Roger do weep wholes apply for lightweight construction or also masonry rebar 10 inch walls covered with 2 coats of moisture resistant deck mud and moisture resistant paint, plus thinset and slate rock (less than 0.4% water absorption) and epoxy grout? Thanks you are THE Best cheers from Costa Rica
I would still have weep holes between the ‘paint’ and the outside.
Are weeping holes required or recommended for a Kerdi membrane alcove tub?
By me – they’re required. By anyone else (schluter), I’m unsure if they are even aware of a method that exists.
Something I’ve been pondering. Could a guy use a small piece of rope laid vertically over the visqueen vapor barrier before the backer board and thin set for the tiles is applied to help wick the water to the weep holes? I’m thinking I they would stop just above the weep holes and not protrude out into the weep hole or tub. Would several of these placed vertically at at an angle not help to direct the water to the weep holes faster. I steal this concept from the ropes the are put in exterior brickwork. Very good article you have here and I appreciate the help.
I suppose it would work just fine.
I just bought a house that had a master shower cover up. 6 inch tiles over an existing marble slab shower wall.
Caulked all around the bottom.
There is mold in and on the bottom edge. So I am scraping it all out, what should I replace it with or should I just leAve it Open? There is a plastic shower pan
You should replace it with silicone but be sure to leave weep holes in it.
Just wanting to make sure I understand “weep holes” correctly. As you see in the picture, there is a slope on each side of the shower pan, towards the front (or where doors will be). Have I caulked correctly? i.e. left a gap for moisture?
Absolutely correct! Excellently done.
The weep holes on my shower pan are open, looks to have been done correctly but what stops the water from working its way out the front of the shower? I obviously have some kind of leak you can see in the picture l. I assumed it was the weep hole allowing the water behind the silicone and out the front. What do you think?
Thank you sincerely great advice on this site!
I see no photo. The path of least resistance is what prevents it from working to the front of the shower. If the water can get out an open hole or get out by working its way behind silicone and forcing its way out – it’s going for the open hole. Negative hydrostatic pressure does not allow water INTO the weep hole. There is always more water behind it than in front of it – physics. If you want to send the photo to Roger@FloorElf.com I’ll take a look and see if I can tell where it’s coming from.
We just finished a tub/shower/tile installation. Between the tub and the tile we grouted along the tub deck and down the apron. It’s an apron front alcove tub and all walls are waterproofed with Schluter Kerdi board.
Everything about the tub and tile installation went fine, except this one thing. When we take a shower we get a small amount of water wicking along the grout line in the deck, down the grout line between the tub apron and the tile, and sometimes reaching the floor when we take a shower. It’s not water spray or spill from the tub deck.
I’ve tested it by applying water to the grout line on the tub deck and watched it wick. I’s not coming from behind the deck, and the tub is level. I’m thinking that I should cut a short channel in the grout near the outside of the tub to break the wick. What do you recommend?
I would get some matching color silicone, dig the grout out completely for and area about 1/2″ long and replace it with the silicone. Once the water hits that it will no longer wick.
Great site! I am a complete noob at this, trying to learn enough to understand a problem in my master shower. Hope you can shed some light…
We have a Wedi system with 3 tile walls and tile floor and a tile curb on one side. We have discovered (moisture meter) water is accumulating behind the bottom row of wall tiles, even on the curb. The line where wall meets floor is caulked. I’m told the floor tiles are grouted with acrylic based grout, the walls have cement based grout.
The builder is pushing to open up some weep holes in the existing caulk line. But based on what I read on your site, weep holes are only for showers with one piece acrylic pans?
So question is:
1) Why is water not draining into the Wedi drain?
2) Since floor is tile, shouldn’t water run underneath the tiles from wall to the drain?
3) Should I do the weep holes or replace all the caulk with cement based grout, which should allow the water to seep out?
1. Because acrylic grout is not porous and is not allowing water to flow through it to get to the drain.
3. I would replace the grout, but either should suffice.
Have just read through your explanation of weep holes. What I am wondering is, do all tubs have a lip to catch the water behind the wall and direct it back to the tub? I have always understood that caulking was needed all the way around to keep water from dripping into and getting inside the wall?
More importantly (!) –
have ripped out the nasty old silicone caulk from around the rail of a sliding glass shower door — the rail itself does not have weep holes — it’s a flat piece of metal — L-shape. Are flat rails of this design supposed to be angled higher at the outside edge and slant downward toward the inside so that water rolls off back into the tub? I can’t “uninstall’ the whole thing and have to deal with what I’ve got. Do I try to “build up one side” with plumber’s putty underneath? It’s all wet under the rail and I can’t imagine, short of using a blow dryer, that it would dry out on its own in my lifetime Do I also leave/create weep holes on the inside edge of the caulking? If I do, I just see water getting back under the railing and sitting there….not enough ventilation for it to evaporate, and as I can’t get under it to put a strong bead of silicone, am thinking I’d better not create weep holes? This is stressful…! Understand I should use silicone….do you recommend something in particular? Home Depot has mostly DAP Kwik Set products? A lot of people recommend GE Silicone II?
Thanks for you help,
how do you create such a neat weep hole in the caulking. Is there any particular technique and how big are the weep hole slots. I’m guessing from photos they are somewhere between 1/4 to 3/8 inch. I am ready to caulk a 3ft by 3ft shower I’ve completed and wondered if putting 2 weep holes in the back corners would be sufficient.
-Wonderful website, great easy to follow to explanations, and I definitely LOL’ed a few times. Also purchased two of your ebooks, GREAT!
-After tile is installed, do you SILICONE your changes of plane FIRST and then grout? Or do you GROUT FIRST and then silicone the changes of plane?
-I’ve been searching the site to find this discussion but can’t locate it. I apologize if you’ve already addressed this somewhere!
Thanks and All the Best to you from Maine!
Great site elf!
I’m a little confused about weep holes with wedi – it sounds to me like I wouldn’t need weep holes because all of the moisture is funneled into the Wedi drain, right?
But my pan is an acrylic pan with Wedi walls. I rabbeted the sheets of Wedi for the walls and attached them to the pan flange.
The weep holes are between your substrate and tile, the substrate should be fully sealed. You don’t want to trap moisture between the wedi and tile.
Hi there. We just moved into a house and the 1st floor shower was a closet from the bedroom next door, converted into a shower in the powder room. It is in 3 separate pieces and then the shower pan. I removed all the old caulk and replaced with new. I then noticed that when you are standing in the shower, it literally feels so not stable. Like you can feel it moving. Now, only after a few showers, the caulk is split and there are cracks and mildew building! What do I do? Was it installed wrong in the first place? Is there any way to fix? I was thinking of filling the base up with heavy books and recaulking it. What do you think? Thanks!
It may or may not have been installed incorrectly. You want to silicone it with 100% silicone, not caulk, and if you weigh down the base until the silicone cures it’ll give you the best bond.
I actually did just that! And had a bunch of company here over the weekend. We we shall see how it held up! Glad you had the same thought process as me! Thanks!
We recently redid our shower. We used a concrete with polymer on the walls. We sanded down the old tile and applied the concrete over it. On the floor, we laid mastic over existing tile and tiled over it with a mosaic tile. Two weeks later we have mastic squirt out from under the floor tile. Obviously, water is getting underneath. What are your thoughts on this? I wonder the problem lies with applying the mastic onto old tile, or weep hole issues or??? We did have a leak prior to this redo, but we thought it was from the plumbing in the wall, which we replaced. It is not leaking out from under the shower now. Very worried. We have spent so much money on this. Looking for advise on what to do next and how to be sure we are solving the problem.
Mastic should NEVER be used in showers, and absolutely NEVER on shower floors. And really absolutely never over existing tile. I don’t understand what you mean by ‘concrete with polymer’ on the walls? Do you mean thinset? If so, then that is correct, provided it is approved for use over existing tile. That is the same thing that should be used on the floor.
Water will ALWAYS get behind your tile, it isn’t waterproof. That’s completely normal, but you need to use a bonding product that is not affected by water – like thinset. Mastic emulsified in a wet environment.
This is the first discussion I have ever been able to find about the dissipation of moisture/water that seeps down to the tub/shower pan. Thank you so much for addressing an issue that has been bugging me for years. (At one point I thought about inserting small pieces of drinking straw into the space along the tub flange and caulking around them.)
Seems to me that 100% of the showers/tub installations I have seen have no weep holes at the tub/shower pan lip at all. And, due to the dearth (sp?) of discussions, I wonder if the tile installers are either ignorant of this issue or simply too lazy to bother?
I believe it’s simply ignorance, they have never been taught. I have NEVER torn out a shower that had proper weep holes left open. More often than not the weep holes in the shower frame are also siliconed over. No one can seem to figure out why there is a dip in the pan and holes drilled into the shower frame.
I had a Shulter Shower system installed in 2009 by “professionals”. Since then I have had to caulk the tile wall to tile floor transition with silicone caulking due to mold appearing every year or two. Am I doomed to do this or is there a better way.
There have been no leaks or other concerns since then. I am guessing they did a put a Kerdi drain and did check for flood test. I was not part of “the beer ceremony” described by Jamie above but I guess that there was one at the time. I read elsewhere in your posts that one must dry the shower after each use. Can you elaborate. Thanks!
Silicone is NOT a permanent product. It is a maintenance product. It needs to be replaced about every 5-7 years. It will, over time, lose it’s elasticity and shrink, this causes it to become unbonded from the tile a LITTLE BIT. Enough so that water will be trapped behind the line of silicone, causing mold to grow. If you remove all of the silicone and replace it with new stuff it will solve your problem – for the next 5-7 years, at which time you should do it again – at the first sign of any mold growth.
Drying out your shower after every use is NOT a requirement, nor a necessity. What it does, however, is cut your cleaning down to essentially just wiping the tile and grout off. I simply allows your shower to dry out much quicker and eases the cleaning burden.
I have a Schluter shower base with kerdi installed over it as well as kerdi covered walls and curb. Do I need weep holes as well? Or does the water behind the tiles make it’s way to the kerdi drain on it’s own. My flood test passed with flying beers, I mean colors.
Thanks as always,
No weep holes required in a topically waterproofed shower. It is designed to work correctly without them.
Flying beers are cool!
Quick clarifying questions. I have a shower that I’m about to waterproof with Redgard. My Hardiebacker is up, and all the seams are taped with alkali-resistant glass fiber tape/mortar. I have a fiberglass shower base, which I’ve sealed to the bottom lip of the hardiebacker with 100% silicone. Here’s my two questions for you, if you could provide some assistance:
1) How high does my Redgard need to go along the walls? Do I stop just above the shower head? Any concern with sealing the shower ceiling, which I plan to tile as well? Is this just a preference thing?
2) Since the bottom edge of my tiled enclosure will butt against the fiberglass shower base, I’ll need to caulk this as well. I’m guessing I’ll need weep holes for this, too, right?
Thanks Roger, you rock!
1. It needs to go two inches above the shower head. Ceiling is a preference.
2. Yes, you need weep holes there.
No weep holes required in a topically waterproofed shower… How does the water get out from between the tile and substrate waterproofed with Kerdi or Redguard?
No weep holes are required in the floor of a topically waterproofed shower. If you are only doing the walls the weep holes are still required.
Thanks! That’s exactly what I did. Great website!
I have a Mustee Durabase 36×48 shower pan that I have installed. There is a lip in front of the weep hole by the curb that I need to tile over but the tile does not sit flush to the wall. Am I supposed to put that lip in a grout line or cut the tile around if? I’m confused, please help.
That vertical lip needs to either be on a grout line or cut around. (I hate those things). You do not, however, need to cut all the way through the whole tile, you can cut a channel on the back of the tile for most of it except the very bottom.