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.
Somewhere I missed the boat on weep holes. I had a cultured marble shower base installed and I tiled the 3 walls for walk in shower and glass door. I didn’t create any weep holes. The basin was installed over the subfloor and kerdi was used over the backerboard. Silicone was used all around the bottom where tile met base.
It’s been about 9 months since I’ve completed shower. Do I need the weep holes and am I too late?
Thanks alot …next time I will use a professional. I hope I haven’t screwed up my shower.
Thanks,
Janice
Hi Janice,
The water that gets behind your tile should have a place to drain. That place is the weep holes. It’s not too late (unless the wall outside your shower is crumbling
). You can simply cut the weep holes out of the silicone bead where you need weep holes.
Does my shower niche need weep holes? I’m following ur niche article and it wasn’t mentioned. While on the subject: I left a 3″ depth for one-tile width on the niche, only to find out down the road the bull noses i was using needed to pull forward to cover the (subway) wall tile. Now I have the dreaded 1/4″ gap to deal with. Don’t yell at me! I’m needing more weep holes than you can imagine on this project…
Hi Wendy,
I DON’T YELL!
No need for weep holes in the niche – it’ll continue to run down the wall provided the bottom of your niche is sloped correctly. I understand you needed to pull the tile forward to cover the wall tile – the tile you put in the back of the niche should be the same thickness. So you moved it forward one tile thickness and it should leave you one tile thickness for the one tile behind your bullnose.
Hi Roger – I need help. We have one of those bathtubs/whirlpool type of tubs. We did not install it. It was installed by the previous owner who was an idiot and did things half-a….! I have a few issues that I am hoping you can help me with.
1) The tub was not installed correctly. There is tile on the walls. But there is a huge gap between the tile and tub. I have had to recaulk the tub every year or so, because after a year, the caulk starts pulling back (shrinking), leaving gaps and causing leaks. If I dont replace the caulk, after a year or so, leaks occur and drips down into floorboard and down to the main floor. And when I caulk, I have to put on a huge glob of caulk because of that gap between tile and tub. So, a couple of questions. Is there a caulk that you would recommend that has minimal shrinkage over time and best adherance properties to the tub? I was thinking, that maybe I need a different strategy when I re-caulk this time. Instead of just applying a thick glob of caulk (filling in the gap and connecting the tile and tub) along the tub in one application, I thought of applying the caulk in 2 stages. The 1st day of caulking, I would fill in the gaps first so that the tile is flushed against the tub. Then when that has dried, on the 2nd day, I could then apply caulk over that (the finishing caulk) and its what I would see when taking a shower. What do you think?
2) We have never seen weep holes in our tub. I don’t think the tub or in actuality the bathroom was installed properly. So, I’m worried that installing a weep hole could cause water damage instead of preventing water damage. What should I do?
3) There are some cracks in the grout of the tiling in bathtub. What’s the best material to use to fill it in quickly and cheaply to ensure its not leaking into walls?
FYI – we are planning on complete remodeling in a couple of years. So, didnt want to spend too much $$$ on this. Just want to make sure we prevent leaks from occurring.
Thanks in advance for your help and advice!!
Misheil
Hi Mishell,
I can guarantee you the shower substrate was not waterproofed correctly. If you have leaks when the caulk shrink that is indicative of no waterproofing. Your idea with the double-bead of caulk will work as well as anything. You can also get some backer rod, which is a foam rod, and place that in the gap and caulk right over it. The backer rod fills the space behind caulk. The less caulk you have in there the less it will shrink. 100% silicone would be better than regular caulk. It remains it’s elasticity longer.
You should still install weep holes in there. The water that is behind the tile can at least have a chance to get out rather than sitting back behind the tile. It will not cause water to get to the substrate – the tub flange prevents that.
There is no material you can put over tile or grout to prevent water from getting behind your tile. Water will get behind your tile – it’s normal. That’s why the substrate itself needs to be waterproofed. At this point just fill it with more grout. Unsanded would be better – it’s more dense.
Roger,
Can you please educate the home inspectors out there concerning weep holes in showers (with manufactured pans) and tubs?
I completed my master bath renovation and tiled my shower leaving weep holes, per your instructions. Job came out beautifully. As you probably guessed, I am selling my house and some lucky folks put a contract on it. Their inspector noted in his report that the “shower needs to be caulked – gaps are noted.”
I do not want our lucky buyers to muck up my work by plugging up the weep holes. So, please, get on the home inspectors’ forum, or where ever else they hang, and tell them to educate themselves about tile.
Mark
Hey Mark,
I’m trying my best. There is a large forum for home inspection to which I subscribe. Strangely enough I just received an update from them today. I’ll write something up there this weekend about the weep hole issue.
This is a two part question.
Q1: I have already set the tile around the back of my tub and apparently left to much gap between the tile and tub. It is right at a 4/16″ to 5/16″ mark. So do I fill it up with caulk or is there a better option?
Q2: Weep holes? I have an old cast porcelain tub. Are these in the tub or simply something you do at the base of the caulk line?
Hi Rhonda,
1. That is a large gap but you can get some ‘backer rod’, which is small cylindrical foam to fill most of the space and install silicone over the front of it. This prevents a huge bead of silicone (which leads to drying out and cracking) and still gives you compensation for movement. You can find it in the window and door section of your local big box or hardware store.
2. Some tubs have them, some don’t. The older cast iron tubs do not. In that case you simply do it in the silicone line at the bottom. (Leave the backer rod out of that area as well.)
Have a whirlpool tub there is 3 weep holes on back wall of tub and 2 each on sides of tub. Im a little confused though if they are built in do I still need to leave that inch opening in the silicone caulk? Thank you
Hi Mary,
Those should actually be overflow holes – not weep holes. They have nothing to do with the tile installation, only the tub itself. Unless you have weep holes between your tile and waterproofing at the bottom of the tub so that water between the two has some place to drain then yes, you always need them.
Okay came here to ask about sealing the grout, only to read about weep holes. This is the first I’m hearing about weep holes. I have no idea if the tub had them built in because I wasn’t looking for them. I have an old porcelain/enamel tub. I mean I silicone the vinyl to the flange of tub but I was wondering where the moisture would come out. Have caulk yet, so I guess I should make weep holes? My original question was how coats of sealant should I put on the grout?
Hey Mori,
I don’t understand the statement ‘silicone the vinyl to the flange…’ – what’s the vinyl? Are you speaking of the moisture barrier? Or something else? If the moisture barrier then there should be no moisture getting behind it – that’s why it’s there. The weep holes are left in the silicone line between the tile and tub only – not in your waterproofing layer. The waterproofing layer contains all the water – you need to install the weep holes in the silicone line of the tile installation so that water is channeled down into the drain.
Or are you talking about something else?
Yes, I was talking about the moisture barrier. I use 4 mil vinyl.
None of the books I read or any other site I looked at, said anything about weeping holes. Since I haven’t caulk yet, I will be putting in weeping holes. Also, how many coats of sealer should I put on the grout?
If it’s a good sealer – one. You need to install coats until the grout no longer absorbs any more sealer. Once you put it on there is won’t soak it in. If it’s a good sealer this normally only takes one or two coats.
I’m using the Enrich’nSeal from Aqua mix that I use for the stone. I’ll check to see if it needs another coat then.
Thanks for all your help.
Thank you for sharing your expertise.
I am going to repair 2 tub installations where the grout has failed and water is getting behind the tile. In both cases the lip on the tub channels the water to the front of the tub (behind the tile) where it runs down to the floor and has destroyed the sub-floor and the wall board. Neither installation has weep holes. When I put weep holes in the new installation, what makes the water come out the weep hole rather than just following the tub surface to the front of the tub like in the original installation that was ruined? Should I build a dam at the front behind the tile (a silicon caulk bad sandwiched between the lip and the tile) that would not allow water to run to the front? Or will the easiest channel for the water always be through the weep holes?
Hey Alan,
The failed grout has nothing to do with water getting behind the tile – that’s gonna happen anyway. It’s designed that way. If the water behind the tile is running down the tub rail to the front of the tub the tub may be out of level – so check that. If it’s level then the water is just following the easiest or only way out. If there were no weep holes it WILL find a way out. Either through the substrate or, if there is a large amount, right where you’ve stated – the front of the tub.
If you place weep holes at the front of the tub and seal the rest of it then the water will go there. It’s physics – if that is the only way out of a sealed system gravity is going to force the water down and the pressure of the weight of the water is going to force it out of the only escape route – the weep holes. Except for the weep holes everything else should be sealed up tight.
Roger, how much gap should there be between the bottom tile and the surface of the tub?
Thanks.
Hey Jay,
1/16″ – 1/8″.
I have a shower basin installation similar to the fuzzy toilet picture. The shower basin is situated in a corner, 2 walls are tiled, 2 walls are framed glass/door. Grout was used where the tile meets the shower pan. There is one weep hole in the grout towards the glass door, that’s it. It also looks like the weep hole was added as an after thought (weep hole is round indicated a drill was used).
2 questions:
– should additional weep holes be added?
– can additional weep holes be added using a drill in the grout where the tiles meet the basin
– if a drill is used, wouldn’t the hole be blocked with dust and debris?
– would it be better to knock out the grout and replace with silicone? (I know nothing about tile and grout, I’d hate to damage the tile or shower).
ok, it was more than 2 questions… I can’t add… I blame the schools
Hah! I blame the schools too – One nation under educated…
Hey Steve,
The grout should be removed and replaced with silicone with proper weep holes. That would be your best option. Using a drill runs the risk of compromising the waterproofing.
Thanks Roger!
I have a Kohler Expanse tub and the tiling flange againt the back wall dips down to the center from each corner. Since it dips down does it need a weep hole there, center of lenght of the tub on back wall? I left one there but walking into the bathroom the tub is the main focal point and that weep hole there sticks out. What would you do in this situation? If it has to have one there thats how it has to be.
Well that’s a shit design.
If the vertical arm of the tub has the lowest point there then unfortunately that’s where it needs to be.
Did I mention that’s a shit design?
Ya it is, you wouldn’t know it just looking at it but when I put up the backerboard the gap towards the center gets quite a bit larger. So I figured that there would have to be a weep hole there due to the water being channeled there. Have you yourself ever ran into this issue before with Kohler tubs?? I think they have a couple designs that do this.
Nope, I’ve never seen one like that. Fortunately.
It may have peen pointed out already, but it probably bears repeating.
Tubs have a lip behind the tile roughly 1 inch higher than the ledge you step over to get into the tub.
So in the event any water were to splash into the weep hole its not just going to run behind the tile and spill inside the wall.
Absolutely correct Mike!
I am, however, I’m a bit confused as to whom (if anyone) that particular statement is meant for.
A: why is water getting behind your tile?
and (B) if its getting behind your tile, you suggest it will just run down the wall and out your “weep hole”? am I missing something here? this sounds sort of absurd.
installed correctly, water should never get behind a tile, or under a roof shingle (for example)
just read the section that says tile and grout are not waterproof, but if so much water is leaking through microscopic pores in the tile and grout that it is running down your wall, I would rip it out and install something else. porcelain? maybe with really small grout joints and latex milk added to the grout?
I’m trying for a waterproof solution if I’m installing a shower, I think thats the point.
Allowing for water to get in and get out seems like not so good of a solution, I think not letting it in is a better one.
*(tile guy of 18 years or so, and not one callback (other than referrals!), if that means anything
A. Water is getting behind your tile because tile and grout are not waterproof
B. Why does that sound absurd to you? Perhaps the ‘something’ you’re missing is gravity?
I never said “so much water is getting behind your tile”, however, if ANY of that water reaches the studs it will create a constant flow, like a water roadway, and begin to swell the studs in the wall.
I do not ‘allow for water to get in and out’, I allow for water to get out. The getting in part is due simply to physics, something I happen to know a little about. Ever heard of hydrostatic-pressure? It’s something that cannot be overcome with the most common tile and stone products being installed. If I could get every customer to buy a tile with an absorption rate of <.01% I would. Most aren't willing to pay over $25/square foot though.
The disconnect in our methods seems to be that you want the tile and grout to provide your waterproofing for you – fine. In the '18 years or so' that you have been a tile guy, you mean to tell me that you have never, ever torn out a shower with tile installed to drywall and the drywall disintegrated? Or never installed natural stone? How do you waterproof that? (Please don't tell me 'sealer')
If tile and grout are so waterproof why the need for a waterproof liner in the shower floor? Would you install your method, porcelain and grout with latex, over drywall only? If not, why not? Why would we need cement backerboards? Why do we have methods set forth by the TCNA and ANSI which demand either a membrane behind the board or a surface membrane over it?
"I’m trying for a waterproof solution if I’m installing a shower, I think thats the point" I am as well, and that is the point. The difference, however, is that I do it with approved methods and techniques and you seem to rely on materials which have no testable standards levied on the manufacturer. Those are the methods I write about and help people with here. If you chose not to utilize the proper approved methods that is entirely your choice. If you would like to learn the intricacies of water management and the physics of correct and approved installation substrate construction, I'll be more than happy to help out.
If your substrate is completely waterproof you don't need to worry about the tile being waterproof enough or adding latex to your grout. It's really that simple.
real water management (in this case) I believe, is not letting water get past the tile. that is why we put tile on shower walls, to make it waterproof. If your system is not completely waterproof, it is inferior to my system. And to answer your question, no, I have never ripped out one of my showers and found water damage. I’ve probably ripped out a few of yours though… heehee
Once again, Jeffry, water getting behind the tile is due to physics. If you choose to believe that my system is inferior to yours then please continue to believe that and build showers which will potentially fail. It keeps people like me who give a shit about their work a lot of job security.
We don’t put tile on walls to make them waterproof. We put tile on walls to decorate it. Water management in a shower is preventing water from getting into the underlying structure and channeling it into the drain. This is done with techniques standardized by the TCNA, ANSI, and IBC. You’ve obviously never heard of them.
I never asked if you had torn out any of YOUR showers, I asked if you had torn out any showers. But that statement tells me that you do, in fact, install tile directly to drywall. Well done – continue to destroy other people’s homes. I’m sure when other people tear them out they’ll see why your method doesn’t work.
I’m certain that when your showers fail and go to shit YOU are the LAST person they would call to fix the problem. And I know you’ve never torn out any of mine. I also noticed the only question you chose to answer was one you’ve chosen to reword in order to throw an adolescent insult into the answer.
“I’ve probably ripped out a few of yours though… heehee”
Sorry, if I had known I was debating with a fuckin’ grade school girl I would have used smaller words. It’s apparent that you have no desire to learn anything new or different about your profession. Actually, with that mindset it’s obviously not your profession, to people like you it’s just a job. People who have professions are always looking for information, education and clarification. Insecure people with jobs think they already know it all. Which one would you be?
Hi Roger,
Thanks again for all your helpful advice. I am putting up wall tile above my steel-enamel tub this weekend and was wondering about this whole weep hole idea. I understand that you need them in order for the space between the tile and waterproof membrane to ‘breathe’. But why not open the ‘mouth’ even wider and not even seal the surface joint anywhere? Essentially just have one big weep hole? I have the tub flange and plastic membrane attached with a bead of silicone preventing any water from moving upwards if it went through this big weep hole anyways. So what would be the problem? I know it’s probably a naive question but it’s been bothering me.
Thanks!
Hey Eric,
The only reason you really don’t want to do that is that it will create a very large gap which may become difficult to clean over the long-term. Other than that no reason you can’t, but it may create some cleaning issues.
Roger, maybe I’m being paranoid (or really dense) but what keeps bath water from going into the weep holes and soaking the walls behind the tile???
Thanks for all of the amazing info!!
Miriam
Hi Miriam,
Gravity. The moisture behind the tile always exerts more pressure going out of the weep holes than anything that may splash in there.
What is the best product to clean tile grout?
Thanks so much.
Hey Mike,
For the most part – oxygen bleach. It is the main ingredient in cleaners like oxy-clean. Works very well.
“oxygen” bleach?? is that a fancy word for store bought bleach?
Nope, I call store bought bleach – ummm, bleach. Dunno where else you would buy it. Oxygen bleach is Sodium Hypochlorite. It is a powdered form of hydrogen peroxide and soda ash (basically) which releases oxygen molecules when mixed with water. The extra oxygen attaches to the dirt or stain and releases it.
ok thanks so much–one more question-how to put in the weep holes if it is silicone sealed–with an exacto knife? and do i need to do anything else?
Yes, exacto-knife. No, nothing else needed.
i know–last posting sounded like my last-and here i am again –
in my other shower/standup without tub–the weep holes are on 2 of the 3 walls–do i need to make one on the third wall or will the water behind that one make its way to the other two weep holes?
thanks for being so patient with the weep hole tutorials!
The two walls is fine. The water will find its way out.
once again -thanks
ok–found the weep holes in the stand alone shower-not covered-so good there-
but in the guest bath with a tub/shower combo i do not see any weep holes and i do see a nice, neat silicone seal between tub and tile. before i cut into the silicone seal to make a weep hole i want to ask if i should do so.
i do understand the whole weep hole concept–but in a tub shower why would the water behind the tiles come out at tub level? wouldn’t any water continue down the wall to floor level? what stops it at tub level to go out the weep holes?
Yes, you should do so. the answer to your second question is simply gravity.
The tile substrate should not be behind the tub, the tub is placed against the wall studs and the substrate installed only down to the top of the tub. The substrate overhangs the tub. It will hit the tub and attempt to find a way to get out – weep holes. If not it will find a way to destroy your wall.
Hey Roger – I have a question about weep holes. My shower has been in production for about a month and I am happy to say it is working out very well. I started by reading your shower manual, your instructional blogs, reading other posts, and got insight from you along the way.
My shower it a traditional / topical combo. My floor is preslope, rubber liner, and mud bed. The liner goes up the walls about 6″ – 8″, and over the curb as per your instructions. The walls are cement board. I left about 1/8″ of gap between the pieces of cement board and filled those gaps with tape / thinset (laticrete gold 253, again per your recommendation). Where the walls meet the floor, I left about 1/8″ gap and filled that gap with Silicone. The walls and a couple of inches of floor have 4 coats of redgard on them.
On to my tile installation. I copied one of your designs (thank you very much). I installed the tile so that my bottom wall tile overlap the floor file. I grouted as normal. Following your instructions I used caulking in the corners to allow for any movement. I also did the same around the bottom. I did not use silicone but rather the caulking that matches the grout color. My grout was a laticrete product and in the corners I used a laticrete acrylic sanded caulk.
So after that long winded commentary, on to my question. What I can remember there was no mention of having to leave a weep hole at the bottom of this type of shower. I’m assuming that because of the rubber liner they are not needed. Any moisture that gets behind the tile will simply find its way down the backer board, onto the liner, and then into the drain. But after reading some of the posts regarding weep holes, I thought I should at least ask.
Thanks again for the info. Appreciate the feedback.
Regards,
Dale
Hey Dale,
Wow, well done. You’ve completed a shower better than 75% of the ‘professional’ contractors.
You are correct, there is no need for weep holes in the bottom of the shower. The weep holes in this type of installations are around the drain where you clamped the liner. They are still there – they’re just underneath the tile and your top mud deck.
i thought that if the shower has a plastic type basin floor (sorry but can’t think of what to call it) that comes up a bit and the tile meets it that it is to be grouted and not caulked
Any change of plane – that includes that particular spot – requires caulk or silicone per standards. The reason is two different materials and two planes sitting in different directions will expand and contract at different rates and directions. Flexible sealant will compensate for that – grout will crack.
thanks-was wondering if i needed to close up the gaps in our new house shower but suspected they were there for a reason.
do the weep holes have a tendency to “grow’? it seems to me that the grout on each end of the week hole might start to sort of chip away
If the seam where your tile meets the tub is grouted then yes, I’m sure over time it will grow, and crack, and… That seam should be caulked or silicone, not grouted. So yes, they may be chipping away.
Roger,
My tile guy is balking at leaving weep holes at the bottom of my marble tile shower, and I’ve read conflicting information on the Internet. I hope you can clear up the confusion. Do you leave weep holes in every shower installation at the bottom joint where a tile wall joins the floor (e.g., marble tile on the walls and shower floor), or only where a tile wall joins a tub or acrylic shower base? Thanks for your help.
Hey Daniel,
Those types of weep holes are only needed where tile meets acrylic tubs or basins. With properly built tiled shower floors the weeping ability is built-in beneath the tile all the way to the drain – you can seal the entire surface joint.
Roger,
Thanks for your response to my earlier weep hole question. But I’m still unclear: are weep holes to be used only to allow water that is already behind the tiles to escape (i.e., when you know you have a problem) or are they part of every good installation right from the start? If the latter, then why there should be any hydrostatic or other pressure forcing water out of the weep hole? And if there is no countervailing pressure (because no significant amount of water or vapor has gotten behind the tile in my good installation), then what’s so special about a weep hole? Why won’t water that collects where shower wall meets shower floor simply run into the weep hole and get behind the tile, as it would if it encountered any other crack or fissure? Isn’t this just what I’m trying to avoid in in any good installation?
Thanks again for your help.
It is to allow water which gets behind the tile to drain. Water WILL get behind your tile because tile and grout ARE NOT waterproof. It’s completely normal. The water that gets back there will eventually (if there are no weep holes) begin to build up the wall. It will run down the wall and simply stay there. Some of it will evaporate back out through the grout lines, but unless you are only taking showers once a month it will not do that faster than more will get back there. They are not only for when you have, or anticipate, a problem. They are to prevent problems.
In a properly built shower every time the shower is used a bit of water gets behind the tile and grout – THEY ARE NOT WATERPROOF. When the shower is shut off some of this will evaporate back out through the grout lines and some will run down the wall behind the tile. This creates a ‘column’ of water behind the tile and grout. If there are not weep holes this column will simply continue to get higher. With weep holes, this water will run out of the weep holes and drain. The weight of the ‘column’ of water behind it creates pressure enough to both push water out of the weep holes and prevent water from entering. The ‘columns’ of water I’m describing are only as thick as the space between your tile and substrate.
If there were a crack or fissure anywhere in the tile installation water will run into it only until the column of water behind the tile reaches that height. After that it will take the path of least resistance – this is usually back into the wall cavity if not properly waterproofed, or simply nowhere. Which means it will sit and fester creating mold, etc. Weep holes flush the water out. You need them – they work and are proper installation points.
Roger,
Love your site – I’ve learned an awful lot in a very short time, and I’m very appreciative.
I understand that weep holes will allow moisture behind the tiles to dissipate. But as the water runs down the shower walls, won’t the weep holes allow it to pass directly behind the tiles (particularly at the juncture between the wall and tub, where it may puddle somewhat)? There the water should meet Wonderboard/RedGard or the equivalent behind the tile, but is this really an optimal solution?
Hey Daniel,
Nope, water is not going to run INTO those weep holes, there will always be more pressure pushing the water down and out from behind the tiles than there is trying to push the drop of water into the weep hole. It’s the pressure variance on the front and back of the tile that allow weep holes to work correctly. If any does actually run into the weep hole ( a tiny bit may ) it will immediately be flushed back out as more water is pulled by gravity behind the tiles to that spot. Not only is it an optimal solution, it is really the only solution when you need to get the water back out from behind the wall tile.
Thanks for the waterproofing pdf! I’ve decided to go with Red Guard.
It all makes sense, but one thing has got me scratching my head…
When installing a bath/shower, do you need to be concerned about waterproofing around the water handle? (not sure what to call it, but I’ve got a single hot/cold control with about a 4-5 inch radius)
It seems to me that water would run down the wall, possibly finding it’s way behind the tile, then piddle out the hole.
Any advice is appreciated. Thanks for the site, it has cleared up a lot of my questions.
Hey Rick,
Place a bead of silicone around the outside of your control valve which will be sandwiched between the tile and redgard. When water runs down the wall and hits the silicone it will run around it and continue down the wall.
I had to reread your article because I am that way.
And a question cropped up. Oh my!
From what you say here, whether the weep holes are built or not,you need weep holes?
I have a cast iron shower base in mine that I am working around . I have not uncovered it yet,but now I am excited to see if they built in the weep holes!
Have a great day Roger! you rock.
Anita
Hi Anita,
Yup, if they aren’t built into the tub you still need to create them in the bead of silicone.