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.Weep hole location in for a tub

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.

Weep hole location in for a shower basinWhen 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 Or, you know, send up smoke signals from your dogs back – he may have just burst into flames again. :D

There you go Kurt, tell mom you win this one and she owes you a six-pack. :D

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.

Weep hole in silicone sealant around bathtubWeep hole in silicone sealant around bathtub
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  • Sarah

    How would one upkeep these holes to prevent mold? My body is unable to get rid of mycotoxins from mold so I want to make sure I keep it clean properly.

    • Dimitri

      This might be an extreme suggestion, but have you given much thought to a decently-sized (one that is rated at least double the room size) dehumidifier?

      • Sarah

        Yes! I use one in the bathroom. Just didn’t know if I should be spraying something in these holes if I can’t close them.

        • Dimitri

          If you’re still getting mold even after running a dehumidifier (e.g. not just a humidity-triggered ventilation fan) all the time, then I guess a periodic hit of windex couldn’t hurt.

  • Bill

    I don’t understand where does the water that goes through the weep holes and into the shower come from and how do you check to see if your weep holes are clogged?

  • Kevin Vernon

    Can to much water get through weep holes and create mold on wood trim behind shower basin?

  • Bonnie

    Both of the tub/shower enclosures at the manufactured home I moved into are DIY tile jobs. I can’t use the one in the master bath because there is obvious floor damage under the tub & it feels like the tub is gonna fall through. So I just use the other one. I started to notice the caulk where tub meets tile was looking pretty bad & starting to peel, so I decided to remove & re-caulk it.
    After scoring the caulk & pulling it out, I discovered behind it was wet all the way around, & there were these wet tube like things of foam stuffed in to fill the very large gap (about 1/2-3/4 inch in depth & width) all the way around with the exception of the wall where faucet & fixtures were. I’ve lived here 3 years & never had an issue with this shower until now. It wasn’t just damp, it was soaked.
    So I have 2 questions. One is, apparently, the foam tubing, or backer bars, as I’m told, were pushed in there so that such a big gap could be caulked. So if there needs to be a space between the wall & the tile for the water to go into a weep hole to drain, wouldn’t that be blocking it? Could that be why there was water behind the caulk? Or could it just be that the caulk was coming up & allowed water behind it?
    My other question is how else can I caulk such a large gap between the tile & tub? I feel like there should be caulk in between to support the tile & accommodate weight & movement in the tub. But how do I successfully caulk such a huge gap? Because the stuff that was stuffed in there was obviously not the way to go. If there is a way to caulk it correctly, would leaving weep holes this wide & deep still work to keep water from building up behind the tile, or would it just allow more water to get in?
    Thank you!

    • Roger

      Hi Bonnie,

      From what you’ve described the caulk is not the problem, lack of waterproofing is the problem. There will always be water behind your tile – always. That is why we waterproof the shower substrate. That waterproofing should run down the wall and be connected to the lip of the tub. This way when water runs down the wall it drips into the tub and not continue to run down into the wall behind the tub to the floor beneath it. A bead of caulk will seal that water in if there aren’t weep holes, but that requires waterproofing from the wall to the tub.
      The backer rod is there to allow caulk to fill that gap, but it has nothing to do with the water damage you are experiencing.

  • Dimitri Katsaros

    Any suggestions on which silicone to use? I was going to go with Mapesil, but then I started to read many reviews of that stuff not curing and just staying in a soft, putty-like state. Maybe something like the GE “Advanced” silicone for kitchen and bath?

    • Roger

      Hi Dimitri,

      Silicone is supposed to stay in a soft, putty-like state. That state is what allows the elasticity to compensate for movement. If it dries out it will crack whenever there’s movement.
      It’s the whole purpose of using silicone rather than caulk.
      Any silicone will do the same thing. When cured it should feel like silly putty.

      • Dimitri Katsaros

        That hasn’t been my experience in the past… once cured, while soft… I wasn’t able to pull it out like putty.

        • Roger

          It should stick to whatever it’s installed over. I was describing the hardness of the cured product, not the ability to move it around. :)

          • Dimitri Katsaros

            okay… that’s what I understood to be the case. Anyway, any fave silicones?


  • Anand J Kumar

    You have written great article explains the weep holes. I have problem I could not solve and the many man and plumber could not solve except asking me to renew a new shower cabin. I asm disappointed as I have paid for visits.
    My problem is when we finished taken bath for 15 minutes afterwards it starts leaking few drops of water from the sealing below Its floor. Our shower is on 2nd floor. It made hole in the sealing and I can see bait of rotten subfloor above. I cleared the two depression I presume weeping holes or depressions in front on either sides of the pane. We have white tiles on the walls. I have cleared the holes scraped as it was caulked before completely. My question is why is still leaking even after cleating the holes? Do I have to clear the back of the tile where ir opens to the weeping hole as it is blocked now. I can feel the lip with my finger at the back in the middle. I don’t understand as no body explained on line. I am poring buckets of water on to the weeping hole and still leaks few drops of water. Can I grout and also Caulk on top all around the joint where tiles meet the pane. Please explain. I appreciate your help. I am frustrated.

    • Roger

      Hi Anand,

      There is a leak in your shower that weep holes are not going to fix. Something is not correctly waterproofed and it is allowing water to enter your substrate and the framing behind it. The ONLY way to fix that is to remove the shower wall and rebuild them with a properly waterproofed substrate.

  • Richard Williams

    Interesting, but I have never seen this in Britain. I don’t believe anyone does this here.

    • Roger

      Hi Richard,

      Most don’t do it here, either. :)

  • Kris

    I’m confused why you would not have weep hole(s) on each wall. My shower has walls on 3 sides and waterproofing is Wedi. Change of plane corners will be caulked. So, using the examples you’ve shown here, water getting through the grout on the back wall will soak into the thinset, run to the bottom of the wall, and… get stuck between caulk lines on my back wall. The corners are all caulk so the water can’t navigate the turn to find a weep hole on a side wall. Am I missing something?

    • Roger

      Hi Kris,

      Nope, you’re not missing anything. I do not FILL the bottom corners of my changes of plane (where the back and side walls meet the tub) with silicone all the way back to the wall – there is space behind that back corner. Tubs are designed in a manner where the very subtle slope causes water to run to the outside edge of the tub rail, where they all (initially) had built-in weep holes. The horizontal rails would channel water to them. You absolutely can have weep holes on every wall. You can eliminate silicone at the bottom of the wall altogether if you want, it is purely aesthetic.

      The part I’M missing is not explaining that my silicone does not fill the planes all the way back to the substrate. That’s on me.

  • N

    We have a one-year-old shower with tile walls and tile shower floor. We recently noticed that the caulking around the base between the wall tile and shower floor tile was bubbling up because there was some water pushing behind the caulk. I removed the caulk and let the area dry for a week. Then, I re-caulked it and let the caulk dry for 5 days. Now, after being used for just 2 days, the same area (about 1-2 inches long) behind the new caulk is pushing out with water seeping out from behind the caulk. I think there must be water getting behind the wall when the shower is being run and trickling down to that line of caulk and getting trapped behind it. Even though we have a tile shower floor, it seems like I should remove that 2-inch section of caulk and create a weep hole that way. Is that correct? Thank you.

    • Roger

      Hi N,

      Yes, that is correct. That sounds like the ideal spot for a weep hole – all the water is already headed there.

  • Desiree

    Thank you for your help. I appreciate you sharing your knowledge to help people. And your correct, I know little about plumbing or the benefit of weep/breathe slots in a shower or tub. I don’t recall ever seeing those in the homes I lived in prior. Possibly just didn’t notice.

    Thank you again and have a nice day.

  • Peter

    I’ve got tile walls and a shower base and the water leaks out the side where the tile meets the base just like you say. I cleaned out the caulk from the weephole and there was grout, so I scraped out the grout about as far back as the depth of the tile (only about the width of a small drill bit) but I’m still getting dripping out the side. How would I know if the weephole is open and working? Do I need to seal up the side of the last tile with caulk to force the water back towards the weep hole?

    • Roger

      Hi Peter,

      To my knowledge there is no visual way to determine if the weep hole is working. Sealing up the outside tile MAY work, depending on what’s behind it. If it is drywall or something else that will absorb water then it may end up being worse as it may force the water into the substrate rather than down and out the weep hole. They only work if the substrate behind the tile is correctly waterproofed.

  • Patricia Allen

    Can these weep holes effect the floor outside the shower? I took up tile on the floor in front of the shower (and in front of these holes) to find the corner of the wood flooring has been wet and is half rotted. Does this have anything to do with these weep holes?

    • Roger

      Hi Patricia,

      They can if your tub or base is not correctly sloped from the weep holes to the drain, which they always are if it’s a manufactured unit. Normally the issue is improper waterproofing and the water is draining down the wall outside the shower. If you have drywall right outside your shower (and possibly inside your shower) water can soak into the drywall, then water will naturally drain down. I would need to know what you have behind your tile (if you know) to be able to be more specific. If you don’t know you can remove the escutcheon (the flange around the shower controls) and look behind it. That will normally give you an idea of what your tile substrate is.

  • Rebecca K

    Hello. We just moved into an 8- year old home with a shower that has these weepholes. The problem is that tiny roaches come out of them. I’ve already cleaned the disgusting shower drain, and when I see these roaches, they are near the weepholes. Are they in the showerpan, the wall or both? I see about one roach per day. Roaches in my shower are not working for me. I’ve tried vinegar and cedarcide. Please advise.

    • Roger

      Hi Rebecca,

      My guess is that they are between your shower wall and tile. It is a very moist area and a perfect spot for these types of critters if they are prevalent in your area. Although normally not an issue (they rarely ‘find’ this area) if you do have them then it’s a pest control matter rather than a shower matter. One idea would be to cut and stuff a piece of sponge up in the weep hole so it will still allow water to drain out and MAY keep the roaches out, but I honestly don’t know about the second part of that.

  • Ginger L Dupree

    Thanks for the information about the weep hole in the shower. A friend used DAP KWIK SEAL ULTRA Advanced Siliconized Sealant. He bought it and did it for me free. I don’t know if this was the best sealant or not but he bought it and did the job for free so I didn’t ask questions. I saw that he left 2′” spaces and he said that they were for expansion. I just went and looked at the holes again in my shower and saw that there was a little dip below the holes (for weeping) so “you” were right. Now I understand about the holes. I was confused at first but reading your information made me understand. Thank you so much, Ginger

  • Tim

    Hey Roger, what about one ginormous weep hole? In other words, just not caulk a tub to wall change of plane so there’s no chance of water being trapped? And if that’s a bad idea, and weep holes as you’ve described (sweet pics btw) are the move, make none in the back wall?

    • Roger

      Hi Tim,

      That’s an option, however, I prefer to silicone at least the major portion of the transition because people tend to not clean very well. Regularly. If there is an open space that large it can definitely lead to a mold issue over time simply from lack of proper upkeep. And proper upkeep on an unsealed transition is tedious and fairly unforgiving.
      The lowest points of your tub rail should be the outside corners on each end, where I’ve install the weep holes in the photos. However, you can place them anywhere you want and as many as you wish. Just keep in mind the above issue with regular cleaning.

  • Dr. Joseph Arguelles

    Hi I just rebuilt a small shower over a fiat terrazo shower pan. The walls are large format porcelain tiles over kerdi board. The space behind the tile and mortar is waterproofed and sealed to the edge of the pan. Should I make weep holes?
    What mitigates the water that gets in the weep holes? Is it just a matter of easy to get in – easy to get out?

    • Roger

      Hi Doc,

      Yes, you should make weep holes. Gravity mitigates any small amount of water that MAY get into them, negative hydrostatic pressure causes water to run out rather than in.

      • Kevin Smith


        We’re hoping that you see the message that we sent via Facebook with photos regarding this issue. Water seems to be staying in our weep holes rather than flowing out. Any thoughts?

  • MARK Richmond

    I have a large outdoor balcony 2nd story which last year I used Ditra membrane and metal drain edge. First I red guarded the plywood then used a self adhesive black rubber neoprene thick membrane. Then laid down Ditra and put down tile.
    My balcony is not completely level from north to south but it does drain away from the house. First 6 months I did not notice any problems but then on a large rain storm the side of the stucco which is on south end of the balcony started leaking water. There also are four or five drip line that are yellowish staining my wood beam and white stucco. There are no tile popping or leaks under the balcony. I was considering routing out three 1/2″ weep holes in the side of the stucco to evacuate the water. I do not want mold to start growing and being in AZ it will dry out quickly. Any suggestions?

    • Roger

      Hi Mark,

      Weep holes will work to evacuate the water, but it doesn’t solve the underlying issue, which is essentially water management. Although the deck is not level, you are not directing the water into a specific spot to drain, it simply does so on the lowest points – wherever it wants to. Channeling water where you want it to drain is a key portion of tiling a deck. The waterproofing simply ensures water does not get below that layer, but it still needs to go somewhere. Do you have any type of gutter or channel on the low side of the deck for water to drain into and be directed away from the house?

  • Darrell Moncus

    Just had some contractors come and refurbish both bathrooms. The contractors grouted the corners of the shower as well as the space between the tile and tub (sanded grout). The corners have developed a crack on one side in each bathroom. What would you advise me to do? Should I call contractor to remove grout from corners and use caulk?

    • Roger

      Hi Darrell,

      That is exactly what you should do. Changes of plane require flexible sealant – caulk or silicone – due to differential expansion and contraction. Silicone and caulk can compensate for that, grout can not. Silicone is better and will last longer.

  • Marc

    Hi Roger,
    I am building a walk in kersi membrane shower with foam base and curb. Anyways I was wondering if you recommend caulk with weep holes where the shower wall tile meets the mosaic tile on the shower floor like you suggest above with tub surrounds. I am worried that the weephole will allow water in the shower base to always wick up the mortar behind the walls in this case where as a tub surround I expect the water to continue down to the tub more readily and not be an issue. Also what do you think about using grout to fill the weephole in the caulk?

    • Roger

      Hi Marc,

      There is no need for weep holes in that application. The water will run down the wall and under the tile on the floor into the drain.

  • Shane

    Hi Roger,

    I have those weep holes in my cultured marble shower (near the front where the sliding door is) but I’m getting water damage on the same wall that the weep hole is on. Any thoughts on what’s causing it?

    • Roger

      Hi Shane,

      Many cultered marble showers are placed directly over drywall. The drywall is normally not waterproofed, which means that any water getting behind the ‘marble’ will be soaked up by the drywall before reaching the weep holes. This can also be caused by a compromised seal at the corners and changes of plane. If the substrate behind the weep hole is absorbing water the weep holes may work in reverse.
      What is causing the damage is an improper installation of your cultured marble walls.

  • Sue Van Epp

    If the installer has sealed them up, should I open the weep hole?
    The acrylic shower enclosure even has them built in to the design.

    • Roger

      Hi Sue,

      Yes you should.