I get a LOT of questions from my readers about basic shower construction. I understand that my readers don’t consider this stuff basic and there’s no problem with that. The problem is that I end up answering the same questions over and over and over… So, to save what very little is left of my sanity (which is a number roughly equivalent to absolute zero) I will cover some basic things here so I can simply reply ‘read this’.

If you’ve been channeled to this page by one of my smart-ass comments please take no offense to it, I’m here to help. Please understand that I currently have over 3000 comments (questions) on this site which I’ve answered – every one of them. I’m just trying to make your life (mine) easier.  I will continue to answer every question I’m asked, I’m just super cool like that. If, after reading through this, you still have questions feel free to ask them in the comments below.

You can also download my shower waterproofing manual which should answer a lot of questions and cover basic techniques and methods you may be confused about. Go ahead, it’s free.  So without further ado (doesn’t even look like a word, does it?) let’s get on with it. (For all my readers who feel the need to correct me: I KNOW it’s actually ‘adieu’ – I was being facetious. Thanks. )

Leaks

First and foremost – tile is not waterproof. Grout is not waterproof. Adding sealer to your tile or stone will not make it waterproof. Your shower should be completely waterproof before a box of tile is even opened! No matter which waterproofing method you choose, proper substrate preparation is the only thing that will make your shower waterproof.

If you have a leak in your shower – stop using it immediately if at all possible. If that is not possible (it’s your only shower) have the shower repaired – immediately. If you see water leaking it is likely not nearly as much water as you don’t see leaking into your wall cavity and structural framing. By the time you ‘see’ most leaks the framing is normally already considerably compromised.

No, there is nothing you can put over your tile to make your shower waterproof if you have a leak – not even sealer. A tile or stone sealer is made to make your tile and grout stain-resistant, not waterproof. It does this by sealing the pores of the tile and stone to slow (NOT STOP) the absorption of liquid and prevent staining. It only means you have more time to clean up the spilled red wine cherry kool-aid before it stains anything.

Substrates

Drywall is not an acceptable substrate for your shower unless you are using Schluter Kerdi waterproofing membrane – that’s it. Cement backerboards are the standard and there are also other products such as waterproofed, gypsum based boards like Denshield and waterproofed, foam-based sheets like wedi or kerdi board.

Cement backerboards are not waterproof. They are water stable, which simply means that they will not swell or disintegrate when exposed to moisture or water – they won’t change size. But they are just like your driveway, they will soak in water, hold water, and dry out, just like your driveway when it rains. If using backerboards there needs to be a waterproof membrane utilized as well.

Membranes

If you are using a topical waterproofing membrane such as a liquid like redgard or hydroban, or a sheet like kerdi, do not use a moisture or vapor barrier behind your substrate. If you have a vapor or moisture barrier behind your substrate do not use a topical membrane on the front of it. This combination creates two waterproof barriers with your substrate sandwiched between them. any vapor or moisture trapped between them has absolutely no way to dissipate. This is lovingly referred to as a ‘mold sandwich’. It is not tasty. Use either a moisture or vapor barrier behind your substrate or a topical membrane on the face of it. One or the other – never both.

With that said, if you want to use a topical liquid such as redgard on the seams of your backerboard, after you tape and mud them, you can do so without problems. If your moisture barrier and backerboards are properly installed there is no real reason to do so – but if it will help you sleep at night go ahead and do it.

If you are using a topical membrane and you have an exterior wall with either plastic facing or kraft paper facing you need to cut slits into that facing before installing your substrate. If you do not it will create the aforementioned mold sandwich. Give moisture or vapor somewhere to dissipate.

Shower-tub transitions

There should be a gap between your tub or acrylic shower base and the bottom of your backerboard. If you are using a traditional barrier waterproofing method you do not need to do anything with this gap. Do not fill it with silicone! This will trap moisture running down your barrier and it will have nowhere to go. If you are using a topical method you can fill it with silicone if you want. If you are using liquid you should fill it with silicone. This creates a waterproof plane between your membrane and the tub or base so water or moisture ends up in the drain rather than in your wall.

When you tile you can tile right over that gap. You should not fill this gap with thinset behind the tile – it will crack due to movement. Your wall and tub or base will expand and contract at different rates – it will crack any cement-based product you place between the two. This includes thinset as well as grout. You do not need a solid backing behind your tile over this gap – it should be less than 1″ wide. You shouldn’t normally be walking on that tile in that particular spot. Yes, it can just hang there.

Grout

If your grout is cracking it is due to movement 99.9% of the time. Type ‘cracking’ into the search box up there and you’ll find in-depth explanations for your viewing pleasure.

If you have white, or lighter than normal grout when you’re finished grouting it may be efflorescence. This is mainly due to minerals in the water being left on the surface of the grout when the water evaporates. It is usually indicative of either incorrectly mixed grout or using too much water while cleaning the grout – not wringing out your sponge enough. This is normally only on the surface of your grout. Scratch the very top layer of your grout in an inconspicuous spot with your fingernail. If you have the correct, or at least a darker, color beneath the surface that is the likely cause. The easiest, quickest fix, provided it is only the very top layer, is to get some drywall sanding sponges and go over the grout lines very lightly. Just like burnt toast – scrape it to the color you like.

Corners and changes-of-plane

Caulk.

Disagree with me?

Like any other website I get my fair share of people who disagree with my methods or techniques – it really doesn’t bother me. I am more than willing to have a civilized, intelligent conversation about anything tile related. If, however, you simply attack me personally and act like an uncivilized ass I will call you on it – and not in a nice way. I write this blog in a particular manner, it does not mean that I take my profession lightly – I most certainly do not. If I wanted to be a pompous bastard I currently have 19 letters I can place after my name – all tile related. But I’m not a pompous bastard – you can just call me Roger.

If you are a contractor with a customer who has come here for information and I’ve told them you’re wrong – realize that the extent of my knowledge of that particular project is limited to what I’m told by your customer. It does not mean that I am ‘out to get you’ or anything of the sort. I normally limit my replies to those situations by stating the current TCNA and/or ANSI standards pertaining to what I’m told. If you disagree – please let me know in a civil manner, If you’re correct I’ll back it up – I do this everyday, too! If you’re an asshole about it expect the same in return – and please have a thesaurus handy to interpret my reply – I’m a very well educated asshole.

That’s it for now. I will likely add to this post on a regular basis. If there is anything I’ve caused confusion with please, for the love of God, let me know. I can change this page since, you know, it’s my website and all. If you have any questions at all please ask them below – I’ll answer, really.

One of my readers has handcuffed me to the radiator in her basement and won’t let me go until I describe how to build a corner shelf in her shower. And she keeps giving me dirty looks. I guess I’ll do it, then.

See those little shelves right there? (You can click on it for a larger version)  They’re made from the same tile that is on the walls – it matches that way. If you have a two-walled shower with only exterior walls it’s nearly impossible (or at least not very probable) to build a niche – frozen shampoo sucks. It’s also difficult to build niches if you have two exterior walls and one wall with all your plumbing – not much room there, either. So a corner shelf, or shelves, may be the way to go.

And they’re easy to make. And I don’t have pictures of the process.

The only difference in the way you install the tile on your walls is that you need to only install up to the row beneath where you are placing the shelf. You need to install tile up to that point on both walls that meet the corner. The bottom portion of the shelf is going to sit on top of those two rows directly against the walls in the corner. The next row of tile is then cut around and on top of the base shelf piece to lock it into the wall.

First decide how many shelves you need. Cut a full tile diagonally, corner-to-corner, in both directions. This will leave you with four identically-sized triangles of tile – these will be your shelf base, the part that’s locked into the wall.

Next you need to install the tile on both the walls that meet the corner your shelf will be in, all the way up to the row beneath your shelf. With me so far? Once you have those tiled take one of those triangle pieces you cut and flip it upside down. Set it onto the tops of the tile in the corner of the shower, the edges of the wall tile – it should just set there. You flip it upside down so you’ll have a finished surface on the underside of your shelf.

Then measure and cut the tiles for the next row that sit above the shelf. You are only notching out the tile to fit around the corner piece for the shelf. Before you install those, and as you are combing out the thinset on the wall for them, pack thinset against the wall at the back edge of the shelf base. This will  hold that piece in there until everything sets up. Then install the next row of tile on the wall.

Continue to do this until you have all the base pieces in for how ever many shelves you want. When you’re done you should have only one piece of upside-down tile in your corners for each shelf. Once that’s done we can finish up the shelves. You will need one piece of bullnose tile (the long ones with the rounded edges) for each shelf. Cut one side of it at a 45 degree angle. Now measure the front of your shelf from wall to wall – it should be just under 12 inches if you are using 12″ tile. Mark that measurement on your bullnose – measure from the pointy corner of the 45 you just cut all the way across the rounded edge. (Did I just type ‘pointy’??? Jesus…) Cut that at a 45 degree angle in the opposite direction (so it will sit on top of your shelf base wall-to- wall).

Set it up there and make sure it fits – you may have to shave a bit off of it until you get the right fit. Once you’re happy with the size of it butter the back of it with thinset (the same stuff you used to stick it to the wall) and put it on there. You will still have an open triangle in the back of the shelf behind the bullnose – just cut a smaller triangle of tile to fit in there and install it to finish your shelf.

That’s it – let it cure and grout everything up. Grout between the tiles on the front edge of the shelf – you can use caulk there if you want to, but it isn’t necessary, it’s not going anywhere. You do not need to use bullnose on the front edge if you don’t want to – it just looks better that way. If you want to simply use the square edge of the tile that’s fine, it won’t hurt anything. Just cut the top shelf piece to the correct size (it will be smaller than the base piece) and install it.

You can also cut into the tile beneath the shelf for the base if you want to. Like the top shelf in the photo above or the shelf in the photo to the left. It makes it easier and it looks better if you have mosaics or a liner that runs above the shelf. The key to it is that the shelf base is locked into the wall so it doesn’t go anywhere. You can cut them in wherever you want – just get it locked in there.

Also make sure that you put a shim of some sort in the very back corner of the shelf before you cut the tile around it – you need to have it sloped ever so slightly toward the shower and away from the wall – you need water to drain off of it. Don’t slope it so much that your rubber ducky slides off, though.

If you have any questions at all please don’t hesitate to ask me in the comments below. I answer them all, I’m just super-cool like that.

Can I get out of this basement now?

Hello???

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.