If you're doing this for yourself let alone professionally, spend the extra cash and put a few layers of Redgard/Hydroban or use Schluter especially if you're already attempting to waterproof the corners. I've pulled out many showers and cement boards are water-resistant not water-proof. Grout is always waterpermeable hence why most custom high tiling jobs for curbs use solid stone cap or longer tiles since it's high traffic.
I do use Schluter membrane one certain jobs, especially when the shower floor is being tiled. However, it simply isn't necessary to use it in every case and there are drawbacks to using it. These include poorer adhesion of tile compared to the straight Hardibacker I use, and greater time and expense. You should also be aware that Hardibacker now does sell a product with "hydrodefense" which is claimed to be waterproof. Beyond that, I have taken apart somewhere between 65 and 70 bathrooms, and not a single one had water intrusion in the middle of the tile field, even though many of them simply had greenboard backer. Where I DO consistently find water damage is at the floor where the edge of the tub or pan meets the plywood. That's where I spend extra time and expense to waterproof, using self-adhesive flashing.
perfect, all details ive been stuck on for the last week as a diy’r. ive laid slate on floors, and honed marble as well as travertine in 2 kitchens for backsplash; but I have never tiled around the tub and I’m having a lot of anxiety over it.😅
Great videos! My husband redid our bathroom years ago. I'm not sure where he got this from, but in addition to using a bathroom drywall product (not sure of the brand, but it was green), applying kerdi all over the walls, corners and ceiling (we have one of those shimmed-in showers with ugly borders) and covered in 8x14 tiles, he kept saying that there was a need for a large gap at the bottom. Something like it's inevitable that water will get in, as the grout is permeable, so the kerdi will protect the wall behind, and the gap at the bottom allows the water to come out and "breathe" 🤷. It's a ½ inch gap. He then filled the gap with clear bathroom silicone and then put white caulk on top to connect the tiles to the tub. I admit that I haven't been maintaining the shower and saw some dark mold in an area, so today I just removed the caulk and silicone to find nasty, wet, brown slime. Instead of caulking again, I want to use a "seal-a-crack tub surround waterproof adhesive sealer" I got at Home Depot, so it'll take care of the gap. My question is, how do I get the gap clean again and prevent more moisture from forming and needing to take everything out and do another expensive renovation? Is it salvageable?
Oh boy. A lot to unpack here. So, I can only make some guesses about the construction based on your description. You mentioned a green drywall product, which I'm going to assume is "green board." That is no longer used because it is just a slightly more water resistant form of drywall and in wet conditions it can still support the growth of mold, as well as crumbling if it does get wet. Kerdi membrane is a waterproofing product, but, like anything, the devil is in the details. If it isn't installed exactly right it won't work. There was a time when Schluter (who makes Kerdi) did advise installation over greenboard, but pros avoided that. I don't know how your husband handled the detail where the Kerdi comes to the bottom. That whole caulking thing you describe is not something I would recommend. I'm presuming he used thinset that he mixed himself, rather than some pre-made product or mastic? Anyway, it sounds like water has been getting in somewhere and for a long period, and now you have some nasty stuff which may have created a problem with the drywall underneath. The 1/2" inch gap is way too big and cannot really be effectively caulked. At this point you probably have two choices. One is to remove all the caulk you can, clean with bleach and let it air out for a couple days. Then you could attempt to recaulk, perhaps after installing backing rod. The problem will likely return though. That seal-a-crack product doesn't sound promising to me. The second choice would be to remove the first row of tile, and then try to re-tile using a complimentary color or perhaps you still have extra of the original tile. In that case, you would do as I did in the video and keep the gap between tile and tub the same as the grout lines. Then use a silicone caulk there. However, there's no guarantee the original tile on the first row will come off without cracking other tiles or that the substrate underneath is any good now. It may be worth calling in a local tile pro to see if he has suggestions. It's pretty tough for me to offer better advice without seeing the problem in person.
@@enduringcharm Thank you so much for taking the time to respond and providing a helpful answer. I'm never going to neglect caulk or grout ever again! 🤣 You've gained a new subscriber! 👍
@@IamSlacker are the vertical corners caulked or grout? I always use a color matched caulk on the corners of walls because they can crack and water will get it and work it’s way down. Usually the corners next to the shower head. Once it goes down and gets behind the caulk on the bottom it works horizontally because it can’t get through the caulk. I’d run a thin layer of color matching quality caulk on the corners, over the grout line. Use tape for a clean line and work it in with your finger to make sure it gets into any hair line cracks. Good luck 🍀
It really looks like most bathroom remodels would need the backer board to come to the lip only, in order to match existing drywall. In that case, note to self - DON'T use smaller subway tiles for those remodel jobs
I see your method. Thing is filling that area with thinnest will create a area to suck up moisture and create mold over time. Best way is to fill with a sealant from wedi or laticrete flush with the back board. Which foam board is a great option.
I hear of that fear a lot, but it simply isn't true. Antimicrobial products are added to modern mortars, such as "Moldgard" in FlexBond thinset. Mold needs a food source as well as moisture, and neither the thinset nor the tub lip provide that source. If the last row of tile is properly caulked with a silicone caulk against the tub or pan, and if the grout is sealed, there really shouldn't be any water getting behind the tile at all. Of course, homeowners do neglect maintenance. But, in all the baths I've torn apart, that's not where I find mold. It will be located where there is wood, or drywall in the old days, or in the grout. I've never had the lip area be a problem, except right under the faucet when tile was put over drywall or greenboard.
This was super helpful. So basically if you cannot bring the backer board all the way down then you must pick a large scale tile? Do you have any other solutions for when this occurs and your tile is not large scale?
My rule of thumb is that 2/3 of the tile is adhered to the backerboard, so that doesn't have to be a large format tile if you have your tub lip exposed. A 3x6 tile, for example, would be okay if the lip exposure is an inch. Of course, the more adhesion the better. If a client really wants a smaller tile I make every effort to bring the backerboard over the lip. But, sometimes it just isn't in the cards.
I first started doing the flashing after witnessing several disasters in second floor condominiums which leaked down into first floor units. I realized that I could prevent such a problem with some simple flashing.
As a professional tile setter myself you are 100% correct in this video. The only thing you forgot to mention is how those spacers are the best spacers in the world. Like how they are straight on the back side and 4 way on the front side and how you can put them in the back corner and they work as the best guide in the world for the opposing walls to make your grout joints align perfect every single time. Plus you should mention that a tile job turns out the best when the tiles on the back wall go corner to corner and the opposing walls butt into the back wall. Good video E.C.
Yeah, we forget what a pain those old rubber spacers used to be! The plastic ones are much more consistent and also easier to remove after the the tiles are set. I do sometimes use one or two of the old rubber ones when a tile is not uniform or the same size as the rest of the tiles. Another great thing about the plastic spacers is that you can get more use out of them. I have a bucket of 1/8 spacers I've reused countless times.
If you mean a shower enclosure, in which the walls are designed to fit into the tub or pan lip, then you just follow the manufacturer's instructions. Typically those are a snap fit and caulking is not required. Many of those attach directly to the studs. If you are talking instead about a thin, flat panel which is applied to the backerboard using adhesive, I don't install those at all. Those are a poor substitute for tile and basically it's only a bead of caulk which prevents a leak in the corners or the tub/pan joint. If I was forced to use them I guess I might install backerboard using the flashing, seal the backerboard with a waterproofing membrane like Schluter Kerdi, and then use adhesive for the panels over that.
Great vid! I have a question: you can see that your cement board looks almost flush to the tub there, on mine the cement board juts out much ahead of the flange lip. I have a 1/4th gap for expansion between the two, but I'm just wondering if this will cause issues with finishing it if the cement-board is roughly a 1/2 prouder than the tub flange?
Well, the backerboard itself is no more than 1/2 inch, and many brands a little less. So the difference in plane is probably not as much as you fear. Nonetheless, when you have a significant difference between the plane of the lip and the backer, the most important thing is not to choose a small format tile. If you have a 12x12 or a 12x24 tile, the lip area is inconsequential because you can just fill the space with thinset for support but the adhesion to the wall takes place above. On the other hand, if you tried to use a small 3x6 or 6x6 tile, a large amount of the surface area of the tile would be over the lip. That could be trouble as far as adhesion and durability.
Thanks for the explanation. I’m remodeling a 1980’s bathroom, and the original surround had two layers of 5/8” drywall (no waterproof membrane), and the edge was finished with radius tile to step down to the bathroom wall which is a single layer of 5/8” drywall. I’m not sure how it lasted 40 years, but it only failed when grout in the window sill cracked. Windows in shower surrounds were popular in the 80’s for some reason. Have you ever seen the tape over the flange lose adhesion over a period of time?
Your double layer of drywall is odd, but it was routine to use drywall as a backer for tile decades ago. The thing is, I have taken apart dozens of baths built that way which were in perfect condition. Thankfully we don't build that way anymore. On the other hand, I have to roll my eyes sometimes with the modern obsession with waterproofing. Some people go to extremes with waterproofing when it isn't necessary, or preach about the sky falling if a particular brand of waterproofing isn't used. The flashing tape trick I use not as waterproofing, but as a backup in the event the homeowner doesn't maintain the caulk and grout over the years. Sometimes I will also use a waterproofing membrane made by Schluter if I'm concerned about a particular installation. Windows, on the other had, are a big no-no. I remove them if they are found in a shower because it is inevitable that they will fail and allow rot inside the wall cavity and other problems.
Great videos... super helpful. What would you do if the tub lip sticks out past the backer board? I can’t shim my wall for the reasons you’ve described.
Some tub lips are fairly thick but it really shouldn't be sticking out past the backerboard unless the rough opening is actually too big. If the mismatch is greater than, say, an 1/8 inch, you may need to adjust the rough opening or carefully split the distance to minimize the problem. Other solutions include shimming the backer a slight amount and significantly feathering the wallboard joint, or using thinset on the backer to create a little extra space. In extreme examples where the rough opening is too big and the walls can't be moved you may need to shim out an entire wall. See this video for an example of that: ua-cam.com/video/-bViu_9CJ58/v-deo.html
Great video, but just like to know your opinion. Some people fill up the gap between the backer board and the edge of the tub with mortar(tinder), than install tape and after that waterproofing membrane with fabric.
No matter what, the thinset mortar will not stick to the lip-- for any period of time, anyway. So any attempt to make that area more durable is really futile. If you attached tape and waterproofing membrane or a liquid membrane, all you have really done is made a mortar hinge! And to what end? If you intended to use a waterproofing membrane over the whole wall anyway, then no harm done, but there's no reason to make a special point of it. It's wasted effort. By contrast, if you just fill the space with thinset mortar as I have shown, that mortar WILL stick tenaciously to the back of the tile itself. The space is filled and the mortar secure. Now if that area receives a bump or a hit (hey, people do weird things in the shower!) there is support in this backing even though it won't actually stick to the lip. And, as I have said, I install that self-adhesive flashing so that even if a homeowner doesn't maintain the grout or caulk, there will be nowhere for the water to go but back into the tub.
I see you stop the hardiebacker right at the tub edge. What do you do if you're running bullnose down to the floor say 2 or 3" in front of the tub? I'm butting up against wood lath and plaster. Do I run more hardiebacker down to the floor for the extra 2 or 3" width??? Thank you.
Actually, I normally install the backerboard to some point outside the tub or the pan, which is what I did here. As part of the prep before tile, I will use joint compound to feather across the backer/wallboard joint and sand flat. Then I'll thoroughly prime that area, and roll on two finish coats of paint. That is given time to cure fully. Then you can tile over that small painted area, or install a waterproofing membrane over it, close to the edge of the tile line if you wish. How far outside of the tub I go with the backerboard depends on where I can use or install framing for the joint.
Hey what should one do if the tub tortrudes out past the drywall about 1/8 inch but cant screw it anymore to be flush? Sand it flush and then apply thin set?
First of all, you don't want to be cranking down on screws through the flange! Those flanges (steel, fiberglass or acrylic) are not meant for that purpose. Screw down until snug and then stop. Second, you don't want to be sanding anything either, which will ruin the finish. The flange shouldn't be modified at all. Third, I hope you aren't using drywall inside the tub alcove? In that area there should be cement backerboard or a tile backer product like Schluter Kerdi board. An overlap can occur at the edge of the tub with drywall in the rest of the room. To solve your problem of the flange being proud of the backer, there are a number of steps you can take, which I discussed in this video: ua-cam.com/video/FYSZQp-Y_kI/v-deo.html
I'm not sure I follow what you are asking. If you are installing tile of any size on the wall, the cement backerboard should be 1/2". It needs to be that thick to prevent flex.
No, construction adhesives or mastic are not rated for wet applications, and that would fail a building inspection if caught. Thinset works very well and will hold tenaciously even when wet.
Thank you for the video. It is very informative. I have a question. What do you think about using liquid waterproofing membrane (Mapey brand for an instance) on the walls above a bathtub? Thank you.
When I need to waterproof a whole shower I use the Schluter brand Kerdi membrane. It's a plastic membrane with a fuzzy coating that provides waterproofing and good tile adhesion. Liquid membrane can be inconsistent in coverage and adhesion may be questionable. I don't use any of those products. Now, when I tile the floor of a shower I use the Schluter system and run the Kerdi membrane right up the walls. On the other hand, I don't find that a complete waterproofing system is necessary in other cases. Instead I use a flashing system behind the backerboard which I've shown in a number of my videos.
There might be some confusion here. The backerboard is not placed OVER existing drywall in a shower, the backerboard is applied directly to the studs. Half-inch backerboard is used. Where the edge of the backerboard meets the edge of the drywall in the rest of the bathroom you'll need to transition using joint compound just like you would with any drywall. I try to put this transition outside of the wet area and the spackle is thoroughly primed and painted. You might check out some of my other videos for more information.
I'm not sure I follow you--do you mean making a relief cut on the back of the cement backerboard to allow space for the flange? If so, I would discourage that. It weakens the backerboard, it creates toxic dust if you use a saw or grinder, and it's just not necessary. I have yet to come across a bath where I couldn't use either shims to bring the backer out over the lip or my flashing trick and putting the backerboard on top of the flange.
I'm using 4x8 subway tile. I replaced the shower pan. The studs were put in place years ago. I can't reframe it I can't install the backer board over the lip.
A traditional subway tile is 3x6, are you certain yours is 4x8? Either way, you'll have a relatively small amount of tile adhered to the backerboard. There may be some things you can do to lower the backerboard over the lip. If this is a three-wall alcove you can shim out the rear (long) wall so the backer goes overt he lip and down to the pan. If all you have are walls in the same plane as the rest of the bath walls, you MAY be able to relieve the back of the backerboard so that it slips over the lip. It would require a grinding wheel used outdoors, with a mask for dust. There's not much to work with, though, so if the lip is thick that may not be an option. Another idea is to simply use a smaller pan and then you can build out the walls from the rest of the bath. Finally, you can ditch the pan altogether and do a tiled floor, which will get around the problem.
Thanks for the video! This is exactly what i was wondering after installing my backer board. I used your method of the flashing and brought the backer board down to the lip but did not overlap. Unfortunately I already bought small tiles and they’re not refundable. What are your thoughts on inserting a strip of 1/4” Hardie Board into the gap and adhering it to the flashing with construction adhesive to give a more solid backing?
I'm not thrilled with the idea of a filler strip. No matter what you use to fill that space, it isn't going to stick to the flashing or to the lip of the tub if you didn't use flashing. So whatever you put in there isn't going to provide adhesion for the tile, it's just going to fill the space so that the tile doesn't crack if bumped. If you install a small format tile it will adhere to the backerboard with thinset and it will stick to whatever thinset you use to fill that cavity, but that same thinset won't stick for any length of time to the flashing or to the lip. When you caulk the bottom of the tile with silicone that will provide some additional support. If you go ahead with the small tile, I would advise you to get as much of it as you adhered to the backer and be meticulous in the other two details.
@@enduringcharm thanks. It sounds like I have some decisions to make. The bathroom is part of a larger basement remodel so I might be able to repurpose the smaller tile
When I feel the need for a complete waterproofing system I use the Schluter Kerdi product. The plastic is not there for waterproofing, it's there in the event something goes very wrong in the future, such as broken tiles, missing grout, shifted framing, etc. I've seen things! I don't use Durock I use Hardibacker, which is not as porous and which is a stiffer product when installed. There's an old video of mine I made many years ago on this subject which I should probably update: ua-cam.com/video/xk7lNudSV2Q/v-deo.html
Okay on no water proofing harder backer, but I do have a question about the holes you drill through the hardie backer and do not waterproof. So now there is a protrusion directly into your stud that is not waterproofed. Thoughts?
You're going to tile over the backerboard, right? I've not found any water-permeable tile. Take a look at this old video I did years ago: ua-cam.com/video/xk7lNudSV2Q/v-deo.html
Can you please address what you did for the same issue for the flange on the front side of the tub? You have the same issue I have right now - only an 1 1/2" or so. What did you do there?
I’m planning to use a delta shower pan and wanting to tile. The flange is not straight. It has a lip on the top. Do I have the wrong shower pan or do I cut off the lip to make flange go straight up. After cut flange will only be about 1”. What brand would you recommend from Home Depot.
I'm not sure I'm following your description. There is a flange, I gather, but when you say the flange has a lip, what does that mean? Is it that the top of the flange is thicker than you hoped? Or perhaps you picked up a shower base which is supposed to be used with matching fiberglass/plastic walls? Additional information would be helpful...
@@enduringcharm like an upside down L. Delta b12135 6032L. It says it can be used with prefab walls or cement board for for tiling. I don’t know how to seal the transition from flange to cement board. Thanks for responding and the help.
Okay, I looked it up and I see what you mean. Kind of a dumb design, because it's trying to cover two things--both the prefab walls or backerboard for tile. The same choices apply for this design, though. Either you shim out the studs enough to allow the backerboard to go over the lip, or you place the backerboard on top of the lip. If you do the latter, then use Zip System stretch flashing or similar over the lip and under the backerboard.
@@enduringcharm thanks. You’ve been a great help. Especially to ease my mind. Maybe another question. Does water wick up through the soft set mortar? Thanks again
If you prep and tile correctly you'll have nothing to worry about, and this so-called wicking problem is an internet thing. I've taken apart 65-70 bathrooms, many with nothing but wallboard behind the tile, and wicking is just not a problem. However, I use the flashing idea just in case the homeowner fails to maintain the grout or caulk, or something else goes wrong. Check out some of my other videos about tiling, there are important ideas and suggestions in all of them.
Is it normal/possible to have slight flex on the overlap portion of the tile that isnt supported by the backboard? If i push the edge of my tile i can see the sealant joint flexing slightly. No sign of cracks on the tile though. My first thought was water damage behind the tiles but looking at your illustration i can see how small movement is possible?
If I follow your story correctly, you can press on the tile right above where it meets the tub or pan, and you can see movement? That's a red flag. You don't mention what the tile is adhered to--is it cement backerboard, or is it an older installation on drywall or "greenboard?" There are a number of possibilities, including that the tile has come off the backerboard and is just being held by the caulk, that there is wallboard behind the tile which is disintegrated, or that there is cement backerboard which was poorly installed in the first place. Apparently you don't have a leak, but if the tile actually moves you may be on borrowed time. You should have a pro remodeler come in and take a look to give you advice.
@@enduringcharm Yes basically the shower tray I have has 4 upstands and the tiles sit over the lip on 2 sides and I'm assuming it's on drywall only. The wall is only 3-4 years old with no signs of mould or cracked tiles/grout. Any water passing through any gaps in the sealant between the tray and tile should in theory be contained to the tray as the tiles do not touch it and the upstand would stop it escaping. I can push the bottom of the tile and see slight movement in the caulking. My gut feeling is lack of adhesive on the bottom half of the tile that overlaps the drywall rather than water penetration. Providing this area is not pushed inwards and not compromised should it hold for a number of years if this is the case? I can't justify pulling a wall down because of slight movement without more evidence, Especially with the cost element at the moment.
Okay, that's not a normal thing, so something isn't right. You shouldn't be able to move the tile really at all. Obviously I can't diagnose the issue from here, but that's why I think you should have a pro take a look. Possibly you can leave it for now, but at least you'd know if it is a serious problem or just a minor thing with a couple of tiles.
Hey John I love your install method in this video, it’s exactly what I want. I have a question. Can I use a Vikrell tub or an acrylic or some sort of a composite tub? Realize they have a lot more flex in them when you walk on them also can you install something on the floor to glue it down and give it more stability?
Yes, I use acrylic or fiberglass tubs in this situation routinely. As long as only a small portion of the tile overlaps the lip, you'll be fine. The silicone caulk helps absorb movement. Each acrylic or fiberglass tub has it's own installation requirements. Some are meant to be bedded in mortar, others have built in feet of some sort. Some specify both, since the manufacturer is just trying to cover their rear-end and they have no experience in the real world! All acrylic or fiberglass tubs are prone to movement and sometimes squeaking, though. For some tubs installed on their own feet I will reach in underneath and spray expanding foam after installation to help stabilize the tub. Just be careful not to use an aggressive foam that will lift the tub or distort the form.
You know, not one DIY site or video ever mentioned the necessity of bringing the board over the flange for subway tile, like what I'm using. Also, no one mentioned that thinset won't bond to the tub, which always confused me about some people saying to thinset the flange. Thanks for answering that. I bought 3x12 subway tile. So, thinset applied to the flange wouldn't act as enough support for a smaller tile like that? One installer's blog mentioned using a sealant like Sikaflex and mesh tape to seal the joint between board and flange, and then tile over it. Would extending the sealant work for supporting smaller format tile? Or is it no different than just applying thinset to the flange?
You see in this and other videos of mine that I use a flexible flashing tape to go over the flange and under the backerboard, just as insurance in case anything goes wrong in years to come. I do not use any kind of sealant or silicone at the lip before tiling. After the tile is complete, the gap between the tile and the tub is sealed with silicone, which is flexible. Since you are installing a smaller tile, or at least a shorter tile, then you need to get the backerboard over the lip. Thinset will not stick for any period of time to the lip or to the flashing I use. There is no other adhesive approved for this application, either. If I can't get the backerboard over the lip, then I advise my clients that they cannot use a short or small tile in this application. There's no point in installing a tile that is going to pop off the wall in a year or two. The thinset which ends up in the lip area merely provides a backing for the tile so that the tile does not crack there if bumped. The tile needs to be adhered to the backerboard. And, yes, I know some people advise using Schluter membrane over the lip, but that doesn't solve the problem. The thinset under the membrane still doesn't stick to the lip for any period. If you can get at least two thirds of that tile onto the backer board (the size of the lip can vary) that is the absolute minimum requirement in my opinion. It's still a risk with smaller tile, though, so make every effort to get the backerboard down over the lip.
@@enduringcharm Thanks for the reply. I'm making my way through your other videos. Great channel. I've decided to just alter the pattern since I already have the tiles. They're 12 inches long, so I'm going to do vertical bottom row into concentric 90s. I think it will solve a lot of problems for me, like easier cuts across the tile, blend in with the out of level tub better, as well as put at least 80% of the tile on the wall. Your video helped me realize I had to change things up. Thanks again!
I'm learning to reno my bathroom and I appreciate you pointing out to consider the movement of the tub by using caulking. However, if water would ever get behind the backerboard, how would it drain into the tub? Wouldn't the caulking block water from doing so?
To be clear, the flashing is NOT about everyday use. It's there so that years down the line if the homeowner fails to maintain the caulk or grout, or if there is significant framing movement, water isn't going to drain into the wall cavity. In a tiled shower that has been detailed well and has grout and caulk intact there is no water getting behind the tile. There isn't even moisture getting through the grout unless you have a family of 12 who use the same shower all day long.
In order to match the rest of the bathroom wall, the cement board has to sit on the lip of my shower pan. I installed the 9" flashing tape behind the cement board like you did. What should I use to fill the 1/16"-1/8" gap between the cement board and the lip before I start laying any tiles on? Caulking or thinset? If there's no gap (like tightly sit on the lip), do I still to caulk the joint? Will the caulk stick to the flashing tape?
So you have self-adhesive flashing tape covering the lip of the shower pan, and going up the studs all around, right? Then the backerboard comes down to the lip, and hopefully the surface of the backer is slightly proud of the lip? If that's the case you can fill the area of the lip with thinset when you tile and be on your way. There's really nothing gained by caulking that small gap between the backer and the lip as long as you have used the self-adhesive flashing.
@@enduringcharm Yes, the self-adhesive flashing tape covering the lip of the shower pan and going up the studs up to 7" all around. And the surface of the back is out by 1/4". The height of the lip is 1". That means I need to fill the 1" gap behind the tile and below the cement board with thinset. Will the thinset stick to the flashing tap? Having finished tiling, I need to caulk the 1/8" space between the tile and the flange, right?
The thinset won't stick to the flashing, but neither would it stick to the tub lip! It will stick to the back of the tile, though. It will provide a backing of sorts so that if the edge of the tile is bumped or cleaned roughly, the tile won't crack. Use a silicone caulk between the edge of the first row of tile and the tub, and leave that gap free of grout before you caulk. The caulk will also offer some support of the tile.
The space behind the tile where the lip is located is not a yawning canyon, it shouldn't be more than a quarter or three eighths of an inch at most. You'll fill that with thinset when you do the tile. Again, the thinset is really just there to fill the space and act as a backer since it won't stick to the tub or to the flashing if you use my flashing method. You'll wipe the grout joints and the joint between the tub and tile if any thinset squeezes out. After the thinset cures you'll grout that area just like the rest of the wall. The gap between the tile and tub is best cleared of thinset and caulked with a color matched silicone caulk instead. See this video: ua-cam.com/video/_aja8hfhElI/v-deo.html
Great video, as always. One question: Should there be a gap between a backerboard and a lip of the tub? Or the backerboard sits directly on the lip? Thanks.
Thanks so much for sharing this tip and your expertise! One question - do we tape the plastic wrap to the flashing or just let it hang over it with no seal?
To be clear, the flashing and plastic are there in case there is a problem in the future, such as grout or caulking not being maintained or framing movement. You can just overlap the two components so that if water got into a corner, for example, it would run down the plastic, over the flashing and back into the tub. The plastic should not cover the whole wall, only about three feet up from the lip. That's enough to offer some protection but not so much as to create a double vapor barrier.
@@enduringcharm Great, that is what I figured, but I wanted to confirm. Thanks! :) Do you happen to know where I can find guidance on how to put plastic sheathing behind a shower niche? I have one in one of the walls of my shower, but still want to use the method you describe here.
There's really no difference, you can usually sneak plastic behind the niche if you wish. I do prefer the one-piece pre-manufactured niche inserts which are not going to leak. There are some made of plastic, and there are those made by Schluter. I've used both successfully.
You'd just make a pointless mess, and silicone does not mix with wet things. Any squeeze-out of silicone would also be a disaster later when you tried to grout. Just use thinset, Really, it will be fine.
Just to clarify, you're saying that IF you are unable to build/shim the wall out, it's fine to align the backer board in plane with the shower flange. However, you're not saying you can't put the back board over the flange/lip. Assuming you had a wall that you could easily shim, you would still recommend you shim it out and place it over the backerboard. Am I understanding correctly?
Correct. If you can shim and go over the lip it will make life easier for you and provide a better installation. Just leave a gap between backerboard edge and the horizontal surface of the tub or pan in that case. You can caulk that gap with silicone if you wish.
When you finish tiling and grouting you will use silicone to seal the gap between the tab/pan and tile. That also does provide some support. However, it would be foolish to rely on that. If you are using a small format tile you should make certain at least 2/3s of the tile is adhered to backerboard in the area of the lip. If necessary, bring the backerboard down over the lip to eliminate the gap and provide more support.
@@enduringcharm I would do both. Use the silicone as an adhesive at the back of the tile (only if you really can't use the backer board of course) and the put another seal at the base after tiling. I've been taught by my builder to always seal tiles at the bath twice anyway, one bead of silicone at the base when you bed them in and another when you're finished all around the rim of the tub.
To clarify, I would NOT use silicone behind the tile as an adhesive. It's a poor adhesive anyway, and just not intended for that use. It could also trap moisture behind there since it will not allow evaporation and migration of moisture as both thinset and grout will allow. If you are using a small tile you need to get that backerboard low enough over the lip so that 2/3 of the tile is adhered to it. Use shims if possible or relieve the back of the backerboard to fit over the lip if necessary. There is always a way to get it done. I have even shimmed out a whole wall and widened a door casing when there was no other option.
Some say don’t bring backer board over the lip of a shower. Water can get through the base and if it touches the base of the backer board it will wick it up the board and keep it wet, rotting wood, creating mold etc.
My advice is based on experience, not fear. First, as you saw, I use a flashing system behind the backerboard so even if the backerboard somehow became saturated it wouldn't go any farther. Second, the backerboard is covered in tile, then the tile is grouted and the bottom gap by the tub or pan is caulked. Water does not get behind there unless the installation was extremely poor or the homeowner failed to maintain the caulk over a period of years. And, if the caulk is missing, then the water can come right back out! It just isn't the problem it is made out to be.
Great video! I have a delta alcove shower pan that I'm planning on tiling over, and I've got that little lip, but right at the front of the pan on each side, the lip curves in and is flush with the studs, rather than there being this half inch gap where the backer board kinda slides in. It's made for either tile or a surround, but I'm not sure what to do about that weird curve. Do you have any ideas? I hope I'm explaining it right. I wish I could post a picture of it
Yes, it would be nice to have pictures available in these comments! I'm not sure I follow your concern exactly, but it could be that your pan is only designed to have the backerboard sit on top of the flange. If that's the case I would still use a flexible flashing if at all possible, such as Zip system stretch tape. If there are curves or other irregularities in the pan you'd have to cut the tile around them. You may be referring to a small area in the very front of each side lip where the lip suddenly thins. Sometimes this is intended to have the backerboard or drywall to go over that small section as a transition point. You may have a small area that you need to fill with thinset when you tile. If you can use the flashing, though, at least you know that water or moisture will not get into the stud bays.
@@enduringcharm yes that's exactly what I'm talking about! I'll have to get some flashing! I've honestly never used it before but I've only tiled one other shower. I'm a contractor but have only been doing this for 6 years so there's a lot of firsts for me lol. I uploaded a picture of the pan and tagged you in it here on UA-cam. I'm not sure if you got a notification for it! But yeah I think you're right about just putting the backer board right above the flange instead of in that little lip. I was just gonna shave that part in the front off but that's probably not a good idea 😂
Hi John, you have mentioned twice about the “the other video” for applying the flashing tape. Where’s the other video? Could you please post a link for the video? Thx
I've actually mentioned it and shown it in many other tile videos. Here are some examples: ua-cam.com/video/FYSZQp-Y_kI/v-deo.html, ua-cam.com/video/RFfmisZo4H8/v-deo.html, ua-cam.com/video/PUTyeD-jyeY/v-deo.html
Yes, they make color matched caulk in both sanded and unsanded versions. However, let me warn you about something. The quality of these color matched caulks is sometimes not great. At the very least, do not use the sanded versions, even if you use sanded grout. The sanded caulks are meant to approximate the look of sanded grout, but they tend to shrink and cause problems in short order. The unsanded caulks are generally better, but still not the quality of a good silicone caulk. For that reason, if a standard silicone caulk happens to match the grout color (white, black, almond, brown) then I'll use that instead.
Thinset really won't stick to the flashing or to the tub or pan surface. But, it's not there to stick, it's just there to offer support behind that area of the tile in case it gets bumped.
Waterproofing membrane has it's place. I use the Schluter system when I tile the floor of a shower and I run it up the walls, too. However, there is also a marketing-induced obsession with waterproofing which borders on the insane. It isn't required in every circumstance and there are even downsides in using it, including cost and a reduced adhesion over straight cement backerboard. So I use it when I think it's needed and not when I don't. The place I do add waterproofing every time is the edge of the tub or pan where it meets the floor. That's where I find rot or moisture damage in nearly every bath I demo.
@@enduringcharm I bought some waterproofing membrane to go over the backer board for the wall tile and got to thinking of how the most important place to put it would seem to be on the floor around tub. I thought I was probably just wasting my time after I bought it to put on the walls since the waterproof backer board covered with thin set should do the trick. The long n short of it is what you commented above makes perfect sense. Great videos too.
Adding mesh tape or Kerdi membrane wouldn't really buy you anything. The thinset won't stick to the tub lip or flashing, but it will stick to the back of the tile. That provides some support behind the tile, that's all.
I make that gap the same as the grout line spacing, which was 1/8" in this case. That looks best. If you've installed the tub or shower pan well, the movement is limited to the expansion and contraction of the tub material and perhaps some difference in seasonal movement between the wall and floor. That should be nowhere near the grout spacing. If you can actually see movement in the tub or pan when stepping into it, something is wrong.
Typically I use the grout line gap as a measure for the gap between the tub and tile. Make them the same. However, the tub really should not be moving enough to see visually. If the tub is installed correctly you should be able to stand in it and not see movement at the lip. Any movement should be very minimal with weight or with temperature changes.
I hung and finished drywall for over 40 years. The plastic is a NO-NO for me. In the south, North Carolina respectively back in the 1980's they would put 4 mil plastic over the insulation on all exterior walls of newly built homes. My crew & I would come in to hang these homes and everywhere the plastic membrane was there was also a pool of water at the baseplate, even in winter. After about ten years they found out that what some stupid engineer had glorified was actually a nightmare. Kind of like the cars they design now. None of these homes are still standing.
Your concern is partially misplaced. What you are referring to is a situation where you have either a double vapor barrier, or a vapor barrier in the wrong position in the wall cavity. Moisture needs to be able to migrate and not be trapped. But there is a key difference between that issue and what I do with the plastic. In my case the plastic does not cover the whole plane of the wall--it's only covering three feet of a 7 or 8 foot wall. It's not acting as a vapor barrier, only as flashing of sorts. Moisture can still migrate through the wall and not be trapped. Also, if any water were to get through the tile, grout or backerboard, it could only return back to the tub or pan, since the plastic overlaps the lip.
Finally the solution to deal with that tub flange area. Excellent.
Fantastic job. Your explanations are clear and you live in the "real" world where you have to adjust to the building you're given. Thanks!
If you're doing this for yourself let alone professionally, spend the extra cash and put a few layers of Redgard/Hydroban or use Schluter especially if you're already attempting to waterproof the corners. I've pulled out many showers and cement boards are water-resistant not water-proof. Grout is always waterpermeable hence why most custom high tiling jobs for curbs use solid stone cap or longer tiles since it's high traffic.
I do use Schluter membrane one certain jobs, especially when the shower floor is being tiled. However, it simply isn't necessary to use it in every case and there are drawbacks to using it. These include poorer adhesion of tile compared to the straight Hardibacker I use, and greater time and expense. You should also be aware that Hardibacker now does sell a product with "hydrodefense" which is claimed to be waterproof.
Beyond that, I have taken apart somewhere between 65 and 70 bathrooms, and not a single one had water intrusion in the middle of the tile field, even though many of them simply had greenboard backer. Where I DO consistently find water damage is at the floor where the edge of the tub or pan meets the plywood. That's where I spend extra time and expense to waterproof, using self-adhesive flashing.
You addressed my question directly and with perfect detail. Thank you.
perfect, all details ive been stuck on for the last week as a diy’r. ive laid slate on floors, and honed marble as well as travertine in 2 kitchens for backsplash; but I have never tiled around the tub and I’m having a lot of anxiety over it.😅
Thanks .. great explanations. Was able to take all your input and solve my case where I do need to shim out all walls over lip.
Thanks this is the first I've seen done this way and makes alot more sense.
Thank you, that's the exact information I was looking for.
You’re a fantastic teacher! Love your expertise!
Great videos! My husband redid our bathroom years ago. I'm not sure where he got this from, but in addition to using a bathroom drywall product (not sure of the brand, but it was green), applying kerdi all over the walls, corners and ceiling (we have one of those shimmed-in showers with ugly borders) and covered in 8x14 tiles, he kept saying that there was a need for a large gap at the bottom. Something like it's inevitable that water will get in, as the grout is permeable, so the kerdi will protect the wall behind, and the gap at the bottom allows the water to come out and "breathe" 🤷. It's a ½ inch gap. He then filled the gap with clear bathroom silicone and then put white caulk on top to connect the tiles to the tub. I admit that I haven't been maintaining the shower and saw some dark mold in an area, so today I just removed the caulk and silicone to find nasty, wet, brown slime. Instead of caulking again, I want to use a "seal-a-crack tub surround waterproof adhesive sealer" I got at Home Depot, so it'll take care of the gap. My question is, how do I get the gap clean again and prevent more moisture from forming and needing to take everything out and do another expensive renovation? Is it salvageable?
Oh boy. A lot to unpack here. So, I can only make some guesses about the construction based on your description. You mentioned a green drywall product, which I'm going to assume is "green board." That is no longer used because it is just a slightly more water resistant form of drywall and in wet conditions it can still support the growth of mold, as well as crumbling if it does get wet. Kerdi membrane is a waterproofing product, but, like anything, the devil is in the details. If it isn't installed exactly right it won't work. There was a time when Schluter (who makes Kerdi) did advise installation over greenboard, but pros avoided that. I don't know how your husband handled the detail where the Kerdi comes to the bottom. That whole caulking thing you describe is not something I would recommend. I'm presuming he used thinset that he mixed himself, rather than some pre-made product or mastic?
Anyway, it sounds like water has been getting in somewhere and for a long period, and now you have some nasty stuff which may have created a problem with the drywall underneath. The 1/2" inch gap is way too big and cannot really be effectively caulked. At this point you probably have two choices. One is to remove all the caulk you can, clean with bleach and let it air out for a couple days. Then you could attempt to recaulk, perhaps after installing backing rod. The problem will likely return though. That seal-a-crack product doesn't sound promising to me. The second choice would be to remove the first row of tile, and then try to re-tile using a complimentary color or perhaps you still have extra of the original tile. In that case, you would do as I did in the video and keep the gap between tile and tub the same as the grout lines. Then use a silicone caulk there. However, there's no guarantee the original tile on the first row will come off without cracking other tiles or that the substrate underneath is any good now.
It may be worth calling in a local tile pro to see if he has suggestions. It's pretty tough for me to offer better advice without seeing the problem in person.
@@enduringcharm Thank you so much for taking the time to respond and providing a helpful answer. I'm never going to neglect caulk or grout ever again! 🤣 You've gained a new subscriber! 👍
@@IamSlacker are the vertical corners caulked or grout? I always use a color matched caulk on the corners of walls because they can crack and water will get it and work it’s way down. Usually the corners next to the shower head. Once it goes down and gets behind the caulk on the bottom it works horizontally because it can’t get through the caulk. I’d run a thin layer of color matching quality caulk on the corners, over the grout line. Use tape for a clean line and work it in with your finger to make sure it gets into any hair line cracks. Good luck 🍀
It really looks like most bathroom remodels would need the backer board to come to the lip only, in order to match existing drywall. In that case, note to self - DON'T use smaller subway tiles for those remodel jobs
Professional avec at same time a good teacher
I appreciate this explanation. Thank you!!
Thank you. The only explained it & actually made senseand I actually showed what they was doing .Thanks you very much. Good luck to you
Very informative video on a popular subject. Thanks.
I see your method. Thing is filling that area with thinnest will create a area to suck up moisture and create mold over time. Best way is to fill with a sealant from wedi or laticrete flush with the back board. Which foam board is a great option.
I hear of that fear a lot, but it simply isn't true. Antimicrobial products are added to modern mortars, such as "Moldgard" in FlexBond thinset. Mold needs a food source as well as moisture, and neither the thinset nor the tub lip provide that source. If the last row of tile is properly caulked with a silicone caulk against the tub or pan, and if the grout is sealed, there really shouldn't be any water getting behind the tile at all. Of course, homeowners do neglect maintenance. But, in all the baths I've torn apart, that's not where I find mold. It will be located where there is wood, or drywall in the old days, or in the grout. I've never had the lip area be a problem, except right under the faucet when tile was put over drywall or greenboard.
Great explanation. Very helpful. Thank you!
Thanks for this info. Very helpful.
This was super helpful. So basically if you cannot bring the backer board all the way down then you must pick a large scale tile? Do you have any other solutions for when this occurs and your tile is not large scale?
My rule of thumb is that 2/3 of the tile is adhered to the backerboard, so that doesn't have to be a large format tile if you have your tub lip exposed. A 3x6 tile, for example, would be okay if the lip exposure is an inch. Of course, the more adhesion the better. If a client really wants a smaller tile I make every effort to bring the backerboard over the lip. But, sometimes it just isn't in the cards.
Thank you very much brother you have solved some of my problems lol...
Love your videos. Thanks so much for sharing your knowledge.
Thanks for watching!
Fantastic advice! Thank you for making this video!
This is exactly what I needed to know! Thank you!!!
great demo
Really great and informative video! 👍
End line, Thank you
Adjuster here, ty for flashing!
I first started doing the flashing after witnessing several disasters in second floor condominiums which leaked down into first floor units. I realized that I could prevent such a problem with some simple flashing.
As a professional tile setter myself you are 100% correct in this video. The only thing you forgot to mention is how those spacers are the best spacers in the world. Like how they are straight on the back side and 4 way on the front side and how you can put them in the back corner and they work as the best guide in the world for the opposing walls to make your grout joints align perfect every single time. Plus you should mention that a tile job turns out the best when the tiles on the back wall go corner to corner and the opposing walls butt into the back wall. Good video E.C.
Yeah, we forget what a pain those old rubber spacers used to be! The plastic ones are much more consistent and also easier to remove after the the tiles are set. I do sometimes use one or two of the old rubber ones when a tile is not uniform or the same size as the rest of the tiles. Another great thing about the plastic spacers is that you can get more use out of them. I have a bucket of 1/8 spacers I've reused countless times.
Great breakdown, keep it up
What if you are using wall panels and not tile, what do you recommend for that?
If you mean a shower enclosure, in which the walls are designed to fit into the tub or pan lip, then you just follow the manufacturer's instructions. Typically those are a snap fit and caulking is not required. Many of those attach directly to the studs. If you are talking instead about a thin, flat panel which is applied to the backerboard using adhesive, I don't install those at all. Those are a poor substitute for tile and basically it's only a bead of caulk which prevents a leak in the corners or the tub/pan joint. If I was forced to use them I guess I might install backerboard using the flashing, seal the backerboard with a waterproofing membrane like Schluter Kerdi, and then use adhesive for the panels over that.
Great vid! I have a question: you can see that your cement board looks almost flush to the tub there, on mine the cement board juts out much ahead of the flange lip. I have a 1/4th gap for expansion between the two, but I'm just wondering if this will cause issues with finishing it if the cement-board is roughly a 1/2 prouder than the tub flange?
Well, the backerboard itself is no more than 1/2 inch, and many brands a little less. So the difference in plane is probably not as much as you fear. Nonetheless, when you have a significant difference between the plane of the lip and the backer, the most important thing is not to choose a small format tile. If you have a 12x12 or a 12x24 tile, the lip area is inconsequential because you can just fill the space with thinset for support but the adhesion to the wall takes place above. On the other hand, if you tried to use a small 3x6 or 6x6 tile, a large amount of the surface area of the tile would be over the lip. That could be trouble as far as adhesion and durability.
@@enduringcharm Thank you for the reply! This is exactly what I ended up doing! I'm using large format tile, 12x24!
Thanks for the explanation. I’m remodeling a 1980’s bathroom, and the original surround had two layers of 5/8” drywall (no waterproof membrane), and the edge was finished with radius tile to step down to the bathroom wall which is a single layer of 5/8” drywall. I’m not sure how it lasted 40 years, but it only failed when grout in the window sill cracked. Windows in shower surrounds were popular in the 80’s for some reason. Have you ever seen the tape over the flange lose adhesion over a period of time?
Your double layer of drywall is odd, but it was routine to use drywall as a backer for tile decades ago. The thing is, I have taken apart dozens of baths built that way which were in perfect condition. Thankfully we don't build that way anymore. On the other hand, I have to roll my eyes sometimes with the modern obsession with waterproofing. Some people go to extremes with waterproofing when it isn't necessary, or preach about the sky falling if a particular brand of waterproofing isn't used. The flashing tape trick I use not as waterproofing, but as a backup in the event the homeowner doesn't maintain the caulk and grout over the years. Sometimes I will also use a waterproofing membrane made by Schluter if I'm concerned about a particular installation.
Windows, on the other had, are a big no-no. I remove them if they are found in a shower because it is inevitable that they will fail and allow rot inside the wall cavity and other problems.
Great video
Great video! Thank you!
Great videos... super helpful. What would you do if the tub lip sticks out past the backer board? I can’t shim my wall for the reasons you’ve described.
Some tub lips are fairly thick but it really shouldn't be sticking out past the backerboard unless the rough opening is actually too big. If the mismatch is greater than, say, an 1/8 inch, you may need to adjust the rough opening or carefully split the distance to minimize the problem. Other solutions include shimming the backer a slight amount and significantly feathering the wallboard joint, or using thinset on the backer to create a little extra space. In extreme examples where the rough opening is too big and the walls can't be moved you may need to shim out an entire wall. See this video for an example of that:
ua-cam.com/video/-bViu_9CJ58/v-deo.html
Great video, but just like to know your opinion. Some people fill up the gap between the backer board and the edge of the tub with mortar(tinder), than install tape and after that waterproofing membrane with fabric.
No matter what, the thinset mortar will not stick to the lip-- for any period of time, anyway. So any attempt to make that area more durable is really futile. If you attached tape and waterproofing membrane or a liquid membrane, all you have really done is made a mortar hinge! And to what end? If you intended to use a waterproofing membrane over the whole wall anyway, then no harm done, but there's no reason to make a special point of it. It's wasted effort.
By contrast, if you just fill the space with thinset mortar as I have shown, that mortar WILL stick tenaciously to the back of the tile itself. The space is filled and the mortar secure. Now if that area receives a bump or a hit (hey, people do weird things in the shower!) there is support in this backing even though it won't actually stick to the lip. And, as I have said, I install that self-adhesive flashing so that even if a homeowner doesn't maintain the grout or caulk, there will be nowhere for the water to go but back into the tub.
I see you stop the hardiebacker right at the tub edge. What do you do if you're running bullnose down to the floor say 2 or 3" in front of the tub? I'm butting up against wood lath and plaster. Do I run more hardiebacker down to the floor for the extra 2 or 3" width??? Thank you.
Actually, I normally install the backerboard to some point outside the tub or the pan, which is what I did here. As part of the prep before tile, I will use joint compound to feather across the backer/wallboard joint and sand flat. Then I'll thoroughly prime that area, and roll on two finish coats of paint. That is given time to cure fully. Then you can tile over that small painted area, or install a waterproofing membrane over it, close to the edge of the tile line if you wish. How far outside of the tub I go with the backerboard depends on where I can use or install framing for the joint.
Hey what should one do if the tub tortrudes out past the drywall about 1/8 inch but cant screw it anymore to be flush? Sand it flush and then apply thin set?
First of all, you don't want to be cranking down on screws through the flange! Those flanges (steel, fiberglass or acrylic) are not meant for that purpose. Screw down until snug and then stop. Second, you don't want to be sanding anything either, which will ruin the finish. The flange shouldn't be modified at all. Third, I hope you aren't using drywall inside the tub alcove? In that area there should be cement backerboard or a tile backer product like Schluter Kerdi board. An overlap can occur at the edge of the tub with drywall in the rest of the room. To solve your problem of the flange being proud of the backer, there are a number of steps you can take, which I discussed in this video: ua-cam.com/video/FYSZQp-Y_kI/v-deo.html
If you're using a smaller tile 4x6, can you use thinner backerboard in those spots so it has something to grab on to?
I'm not sure I follow what you are asking. If you are installing tile of any size on the wall, the cement backerboard should be 1/2". It needs to be that thick to prevent flex.
Could you not use a construction adhesive like liquid nails on the lower tile row? Then continue on with thinset?
No, construction adhesives or mastic are not rated for wet applications, and that would fail a building inspection if caught. Thinset works very well and will hold tenaciously even when wet.
Thank you for the video. It is very informative. I have a question. What do you think about using liquid waterproofing membrane (Mapey brand for an instance) on the walls above a bathtub? Thank you.
When I need to waterproof a whole shower I use the Schluter brand Kerdi membrane. It's a plastic membrane with a fuzzy coating that provides waterproofing and good tile adhesion. Liquid membrane can be inconsistent in coverage and adhesion may be questionable. I don't use any of those products. Now, when I tile the floor of a shower I use the Schluter system and run the Kerdi membrane right up the walls. On the other hand, I don't find that a complete waterproofing system is necessary in other cases. Instead I use a flashing system behind the backerboard which I've shown in a number of my videos.
When place backboard over existing drywall like in your video. What thickness did you use? 1/4 inch or 1/2 inch?
There might be some confusion here. The backerboard is not placed OVER existing drywall in a shower, the backerboard is applied directly to the studs. Half-inch backerboard is used. Where the edge of the backerboard meets the edge of the drywall in the rest of the bathroom you'll need to transition using joint compound just like you would with any drywall. I try to put this transition outside of the wet area and the spackle is thoroughly primed and painted. You might check out some of my other videos for more information.
What is your opinion on mitering the backer board about 2-3" up from where it meets the tub/pan flange?
I'm not sure I follow you--do you mean making a relief cut on the back of the cement backerboard to allow space for the flange? If so, I would discourage that. It weakens the backerboard, it creates toxic dust if you use a saw or grinder, and it's just not necessary. I have yet to come across a bath where I couldn't use either shims to bring the backer out over the lip or my flashing trick and putting the backerboard on top of the flange.
Like how you use the wood as a straight edge
I'm using 4x8 subway tile. I replaced the shower pan. The studs were put in place years ago. I can't reframe it I can't install the backer board over the lip.
A traditional subway tile is 3x6, are you certain yours is 4x8? Either way, you'll have a relatively small amount of tile adhered to the backerboard. There may be some things you can do to lower the backerboard over the lip. If this is a three-wall alcove you can shim out the rear (long) wall so the backer goes overt he lip and down to the pan. If all you have are walls in the same plane as the rest of the bath walls, you MAY be able to relieve the back of the backerboard so that it slips over the lip. It would require a grinding wheel used outdoors, with a mask for dust. There's not much to work with, though, so if the lip is thick that may not be an option. Another idea is to simply use a smaller pan and then you can build out the walls from the rest of the bath. Finally, you can ditch the pan altogether and do a tiled floor, which will get around the problem.
Thanks for the video! This is exactly what i was wondering after installing my backer board. I used your method of the flashing and brought the backer board down to the lip but did not overlap. Unfortunately I already bought small tiles and they’re not refundable. What are your thoughts on inserting a strip of 1/4” Hardie Board into the gap and adhering it to the flashing with construction adhesive to give a more solid backing?
I'm not thrilled with the idea of a filler strip. No matter what you use to fill that space, it isn't going to stick to the flashing or to the lip of the tub if you didn't use flashing. So whatever you put in there isn't going to provide adhesion for the tile, it's just going to fill the space so that the tile doesn't crack if bumped. If you install a small format tile it will adhere to the backerboard with thinset and it will stick to whatever thinset you use to fill that cavity, but that same thinset won't stick for any length of time to the flashing or to the lip. When you caulk the bottom of the tile with silicone that will provide some additional support. If you go ahead with the small tile, I would advise you to get as much of it as you adhered to the backer and be meticulous in the other two details.
@@enduringcharm thanks. It sounds like I have some decisions to make. The bathroom is part of a larger basement remodel so I might be able to repurpose the smaller tile
Just plastic behind the backer board, no RedGuard on top of it? Just taping the seams? What's your thought on waterproofing the DuraRock?
When I feel the need for a complete waterproofing system I use the Schluter Kerdi product. The plastic is not there for waterproofing, it's there in the event something goes very wrong in the future, such as broken tiles, missing grout, shifted framing, etc. I've seen things! I don't use Durock I use Hardibacker, which is not as porous and which is a stiffer product when installed. There's an old video of mine I made many years ago on this subject which I should probably update: ua-cam.com/video/xk7lNudSV2Q/v-deo.html
Okay on no water proofing harder backer, but I do have a question about the holes you drill through the hardie backer and do not waterproof. So now there is a protrusion directly into your stud that is not waterproofed. Thoughts?
You're going to tile over the backerboard, right? I've not found any water-permeable tile. Take a look at this old video I did years ago: ua-cam.com/video/xk7lNudSV2Q/v-deo.html
Can you please address what you did for the same issue for the flange on the front side of the tub? You have the same issue I have right now - only an 1 1/2" or so. What did you do there?
Can you elaborate? I'm not sure I follow the question...
About time I see one where it's done the way it's supposed to be I always go to lip and thinset in the gap then redgard even if it's during
I’m planning to use a delta shower pan and wanting to tile. The flange is not straight. It has a lip on the top. Do I have the wrong shower pan or do I cut off the lip to make flange go straight up. After cut flange will only be about 1”. What brand would you recommend from Home Depot.
I'm not sure I'm following your description. There is a flange, I gather, but when you say the flange has a lip, what does that mean? Is it that the top of the flange is thicker than you hoped? Or perhaps you picked up a shower base which is supposed to be used with matching fiberglass/plastic walls? Additional information would be helpful...
@@enduringcharm like an upside down L. Delta b12135 6032L. It says it can be used with prefab walls or cement board for for tiling. I don’t know how to seal the transition from flange to cement board. Thanks for responding and the help.
Okay, I looked it up and I see what you mean. Kind of a dumb design, because it's trying to cover two things--both the prefab walls or backerboard for tile. The same choices apply for this design, though. Either you shim out the studs enough to allow the backerboard to go over the lip, or you place the backerboard on top of the lip. If you do the latter, then use Zip System stretch flashing or similar over the lip and under the backerboard.
@@enduringcharm thanks. You’ve been a great help. Especially to ease my mind. Maybe another question. Does water wick up through the soft set mortar? Thanks again
If you prep and tile correctly you'll have nothing to worry about, and this so-called wicking problem is an internet thing. I've taken apart 65-70 bathrooms, many with nothing but wallboard behind the tile, and wicking is just not a problem. However, I use the flashing idea just in case the homeowner fails to maintain the grout or caulk, or something else goes wrong. Check out some of my other videos about tiling, there are important ideas and suggestions in all of them.
Thank you!!
Is it normal/possible to have slight flex on the overlap portion of the tile that isnt supported by the backboard? If i push the edge of my tile i can see the sealant joint flexing slightly. No sign of cracks on the tile though. My first thought was water damage behind the tiles but looking at your illustration i can see how small movement is possible?
If I follow your story correctly, you can press on the tile right above where it meets the tub or pan, and you can see movement? That's a red flag. You don't mention what the tile is adhered to--is it cement backerboard, or is it an older installation on drywall or "greenboard?" There are a number of possibilities, including that the tile has come off the backerboard and is just being held by the caulk, that there is wallboard behind the tile which is disintegrated, or that there is cement backerboard which was poorly installed in the first place. Apparently you don't have a leak, but if the tile actually moves you may be on borrowed time. You should have a pro remodeler come in and take a look to give you advice.
@@enduringcharm Yes basically the shower tray I have has 4 upstands and the tiles sit over the lip on 2 sides and I'm assuming it's on drywall only. The wall is only 3-4 years old with no signs of mould or cracked tiles/grout. Any water passing through any gaps in the sealant between the tray and tile should in theory be contained to the tray as the tiles do not touch it and the upstand would stop it escaping. I can push the bottom of the tile and see slight movement in the caulking. My gut feeling is lack of adhesive on the bottom half of the tile that overlaps the drywall rather than water penetration. Providing this area is not pushed inwards and not compromised should it hold for a number of years if this is the case? I can't justify pulling a wall down because of slight movement without more evidence, Especially with the cost element at the moment.
Okay, that's not a normal thing, so something isn't right. You shouldn't be able to move the tile really at all. Obviously I can't diagnose the issue from here, but that's why I think you should have a pro take a look. Possibly you can leave it for now, but at least you'd know if it is a serious problem or just a minor thing with a couple of tiles.
@@enduringcharm Thank you for your help 👍
Hey John I love your install method in this video, it’s exactly what I want. I have a question. Can I use a Vikrell tub or an acrylic or some sort of a composite tub? Realize they have a lot more flex in them when you walk on them also can you install something on the floor to glue it down and give it more stability?
Yes, I use acrylic or fiberglass tubs in this situation routinely. As long as only a small portion of the tile overlaps the lip, you'll be fine. The silicone caulk helps absorb movement. Each acrylic or fiberglass tub has it's own installation requirements. Some are meant to be bedded in mortar, others have built in feet of some sort. Some specify both, since the manufacturer is just trying to cover their rear-end and they have no experience in the real world! All acrylic or fiberglass tubs are prone to movement and sometimes squeaking, though. For some tubs installed on their own feet I will reach in underneath and spray expanding foam after installation to help stabilize the tub. Just be careful not to use an aggressive foam that will lift the tub or distort the form.
@@enduringcharm thank you sir
You know, not one DIY site or video ever mentioned the necessity of bringing the board over the flange for subway tile, like what I'm using. Also, no one mentioned that thinset won't bond to the tub, which always confused me about some people saying to thinset the flange. Thanks for answering that.
I bought 3x12 subway tile. So, thinset applied to the flange wouldn't act as enough support for a smaller tile like that?
One installer's blog mentioned using a sealant like Sikaflex and mesh tape to seal the joint between board and flange, and then tile over it. Would extending the sealant work for supporting smaller format tile? Or is it no different than just applying thinset to the flange?
You see in this and other videos of mine that I use a flexible flashing tape to go over the flange and under the backerboard, just as insurance in case anything goes wrong in years to come. I do not use any kind of sealant or silicone at the lip before tiling. After the tile is complete, the gap between the tile and the tub is sealed with silicone, which is flexible.
Since you are installing a smaller tile, or at least a shorter tile, then you need to get the backerboard over the lip. Thinset will not stick for any period of time to the lip or to the flashing I use. There is no other adhesive approved for this application, either. If I can't get the backerboard over the lip, then I advise my clients that they cannot use a short or small tile in this application. There's no point in installing a tile that is going to pop off the wall in a year or two. The thinset which ends up in the lip area merely provides a backing for the tile so that the tile does not crack there if bumped. The tile needs to be adhered to the backerboard. And, yes, I know some people advise using Schluter membrane over the lip, but that doesn't solve the problem. The thinset under the membrane still doesn't stick to the lip for any period. If you can get at least two thirds of that tile onto the backer board (the size of the lip can vary) that is the absolute minimum requirement in my opinion. It's still a risk with smaller tile, though, so make every effort to get the backerboard down over the lip.
@@enduringcharm Thanks for the reply. I'm making my way through your other videos. Great channel.
I've decided to just alter the pattern since I already have the tiles. They're 12 inches long, so I'm going to do vertical bottom row into concentric 90s. I think it will solve a lot of problems for me, like easier cuts across the tile, blend in with the out of level tub better, as well as put at least 80% of the tile on the wall. Your video helped me realize I had to change things up.
Thanks again!
I'm learning to reno my bathroom and I appreciate you pointing out to consider the movement of the tub by using caulking. However, if water would ever get behind the backerboard, how would it drain into the tub? Wouldn't the caulking block water from doing so?
To be clear, the flashing is NOT about everyday use. It's there so that years down the line if the homeowner fails to maintain the caulk or grout, or if there is significant framing movement, water isn't going to drain into the wall cavity. In a tiled shower that has been detailed well and has grout and caulk intact there is no water getting behind the tile. There isn't even moisture getting through the grout unless you have a family of 12 who use the same shower all day long.
In order to match the rest of the bathroom wall, the cement board has to sit on the lip of my shower pan. I installed the 9" flashing tape behind the cement board like you did. What should I use to fill the 1/16"-1/8" gap between the cement board and the lip before I start laying any tiles on? Caulking or thinset? If there's no gap (like tightly sit on the lip), do I still to caulk the joint? Will the caulk stick to the flashing tape?
So you have self-adhesive flashing tape covering the lip of the shower pan, and going up the studs all around, right? Then the backerboard comes down to the lip, and hopefully the surface of the backer is slightly proud of the lip? If that's the case you can fill the area of the lip with thinset when you tile and be on your way. There's really nothing gained by caulking that small gap between the backer and the lip as long as you have used the self-adhesive flashing.
@@enduringcharm Yes, the self-adhesive flashing tape covering the lip of the shower pan and going up the studs up to 7" all around. And the surface of the back is out by 1/4". The height of the lip is 1". That means I need to fill the 1" gap behind the tile and below the cement board with thinset. Will the thinset stick to the flashing tap? Having finished tiling, I need to caulk the 1/8" space between the tile and the flange, right?
The thinset won't stick to the flashing, but neither would it stick to the tub lip! It will stick to the back of the tile, though. It will provide a backing of sorts so that if the edge of the tile is bumped or cleaned roughly, the tile won't crack. Use a silicone caulk between the edge of the first row of tile and the tub, and leave that gap free of grout before you caulk. The caulk will also offer some support of the tile.
@@enduringcharm Thank you very much for your professional advice.
great, so how do you grout the vertical 1 inch before you reach backer board?
The space behind the tile where the lip is located is not a yawning canyon, it shouldn't be more than a quarter or three eighths of an inch at most. You'll fill that with thinset when you do the tile. Again, the thinset is really just there to fill the space and act as a backer since it won't stick to the tub or to the flashing if you use my flashing method. You'll wipe the grout joints and the joint between the tub and tile if any thinset squeezes out. After the thinset cures you'll grout that area just like the rest of the wall. The gap between the tile and tub is best cleared of thinset and caulked with a color matched silicone caulk instead. See this video:
ua-cam.com/video/_aja8hfhElI/v-deo.html
Great video, as always. One question: Should there be a gap between a backerboard and a lip of the tub? Or the backerboard sits directly on the lip? Thanks.
You should see the previous video here: ua-cam.com/video/FYSZQp-Y_kI/v-deo.html
Thanks so much for sharing this tip and your expertise! One question - do we tape the plastic wrap to the flashing or just let it hang over it with no seal?
To be clear, the flashing and plastic are there in case there is a problem in the future, such as grout or caulking not being maintained or framing movement. You can just overlap the two components so that if water got into a corner, for example, it would run down the plastic, over the flashing and back into the tub. The plastic should not cover the whole wall, only about three feet up from the lip. That's enough to offer some protection but not so much as to create a double vapor barrier.
@@enduringcharm Great, that is what I figured, but I wanted to confirm. Thanks! :)
Do you happen to know where I can find guidance on how to put plastic sheathing behind a shower niche? I have one in one of the walls of my shower, but still want to use the method you describe here.
There's really no difference, you can usually sneak plastic behind the niche if you wish. I do prefer the one-piece pre-manufactured niche inserts which are not going to leak. There are some made of plastic, and there are those made by Schluter. I've used both successfully.
Could you silicone the lip and thinset on the backerboard? Half and half essentially
You'd just make a pointless mess, and silicone does not mix with wet things. Any squeeze-out of silicone would also be a disaster later when you tried to grout. Just use thinset, Really, it will be fine.
Just to clarify, you're saying that IF you are unable to build/shim the wall out, it's fine to align the backer board in plane with the shower flange. However, you're not saying you can't put the back board over the flange/lip. Assuming you had a wall that you could easily shim, you would still recommend you shim it out and place it over the backerboard. Am I understanding correctly?
Correct. If you can shim and go over the lip it will make life easier for you and provide a better installation. Just leave a gap between backerboard edge and the horizontal surface of the tub or pan in that case. You can caulk that gap with silicone if you wish.
If you have really small tile, could you not use silicone at the bottom to hold it in as well as the tile adhesive at the top?
When you finish tiling and grouting you will use silicone to seal the gap between the tab/pan and tile. That also does provide some support. However, it would be foolish to rely on that. If you are using a small format tile you should make certain at least 2/3s of the tile is adhered to backerboard in the area of the lip. If necessary, bring the backerboard down over the lip to eliminate the gap and provide more support.
@@enduringcharm I would do both. Use the silicone as an adhesive at the back of the tile (only if you really can't use the backer board of course) and the put another seal at the base after tiling. I've been taught by my builder to always seal tiles at the bath twice anyway, one bead of silicone at the base when you bed them in and another when you're finished all around the rim of the tub.
To clarify, I would NOT use silicone behind the tile as an adhesive. It's a poor adhesive anyway, and just not intended for that use. It could also trap moisture behind there since it will not allow evaporation and migration of moisture as both thinset and grout will allow. If you are using a small tile you need to get that backerboard low enough over the lip so that 2/3 of the tile is adhered to it. Use shims if possible or relieve the back of the backerboard to fit over the lip if necessary. There is always a way to get it done. I have even shimmed out a whole wall and widened a door casing when there was no other option.
Some say don’t bring backer board over the lip of a shower. Water can get through the base and if it touches the base of the backer board it will wick it up the board and keep it wet, rotting wood, creating mold etc.
My advice is based on experience, not fear. First, as you saw, I use a flashing system behind the backerboard so even if the backerboard somehow became saturated it wouldn't go any farther. Second, the backerboard is covered in tile, then the tile is grouted and the bottom gap by the tub or pan is caulked. Water does not get behind there unless the installation was extremely poor or the homeowner failed to maintain the caulk over a period of years. And, if the caulk is missing, then the water can come right back out! It just isn't the problem it is made out to be.
Great video! I have a delta alcove shower pan that I'm planning on tiling over, and I've got that little lip, but right at the front of the pan on each side, the lip curves in and is flush with the studs, rather than there being this half inch gap where the backer board kinda slides in. It's made for either tile or a surround, but I'm not sure what to do about that weird curve. Do you have any ideas? I hope I'm explaining it right. I wish I could post a picture of it
Yes, it would be nice to have pictures available in these comments! I'm not sure I follow your concern exactly, but it could be that your pan is only designed to have the backerboard sit on top of the flange. If that's the case I would still use a flexible flashing if at all possible, such as Zip system stretch tape. If there are curves or other irregularities in the pan you'd have to cut the tile around them. You may be referring to a small area in the very front of each side lip where the lip suddenly thins. Sometimes this is intended to have the backerboard or drywall to go over that small section as a transition point. You may have a small area that you need to fill with thinset when you tile. If you can use the flashing, though, at least you know that water or moisture will not get into the stud bays.
@@enduringcharm yes that's exactly what I'm talking about! I'll have to get some flashing! I've honestly never used it before but I've only tiled one other shower. I'm a contractor but have only been doing this for 6 years so there's a lot of firsts for me lol. I uploaded a picture of the pan and tagged you in it here on UA-cam. I'm not sure if you got a notification for it! But yeah I think you're right about just putting the backer board right above the flange instead of in that little lip. I was just gonna shave that part in the front off but that's probably not a good idea 😂
Hi John, you have mentioned twice about the “the other video” for applying the flashing tape. Where’s the other video? Could you please post a link for the video? Thx
I've actually mentioned it and shown it in many other tile videos. Here are some examples: ua-cam.com/video/FYSZQp-Y_kI/v-deo.html, ua-cam.com/video/RFfmisZo4H8/v-deo.html, ua-cam.com/video/PUTyeD-jyeY/v-deo.html
@@enduringcharm , Thank you very much John!
Can you use grout color matching caulk between the tub and tile?
Yes, they make color matched caulk in both sanded and unsanded versions. However, let me warn you about something. The quality of these color matched caulks is sometimes not great. At the very least, do not use the sanded versions, even if you use sanded grout. The sanded caulks are meant to approximate the look of sanded grout, but they tend to shrink and cause problems in short order. The unsanded caulks are generally better, but still not the quality of a good silicone caulk. For that reason, if a standard silicone caulk happens to match the grout color (white, black, almond, brown) then I'll use that instead.
Won’t the thin set in the backer board to the tub crack as well?
Thinset really won't stick to the flashing or to the tub or pan surface. But, it's not there to stick, it's just there to offer support behind that area of the tile in case it gets bumped.
@@enduringcharm ahhh, so is more of a filler. Thanks
New sub!! Thanks
Good video ,what about waterproof membrane,does it work or is it good
Waterproofing membrane has it's place. I use the Schluter system when I tile the floor of a shower and I run it up the walls, too. However, there is also a marketing-induced obsession with waterproofing which borders on the insane. It isn't required in every circumstance and there are even downsides in using it, including cost and a reduced adhesion over straight cement backerboard. So I use it when I think it's needed and not when I don't. The place I do add waterproofing every time is the edge of the tub or pan where it meets the floor. That's where I find rot or moisture damage in nearly every bath I demo.
@@enduringcharm I bought some waterproofing membrane to go over the backer board for the wall tile and got to thinking of how the most important place to put it would seem to be on the floor around tub. I thought I was probably just wasting my time after I bought it to put on the walls since the waterproof backer board covered with thin set should do the trick. The long n short of it is what you commented above makes perfect sense. Great videos too.
do u put any of the cement board tape on the bottom or just the thinset
Adding mesh tape or Kerdi membrane wouldn't really buy you anything. The thinset won't stick to the tub lip or flashing, but it will stick to the back of the tile. That provides some support behind the tile, that's all.
@@enduringcharm thanks alot great video
how much space u left at bottom between tile n tub? thanx
Typically that gap is the same as the grout lines above.
This helps. I dont have to tear down my backer board. I was afraid my board was too high. But it lines up and my tile is large enough to make it work
Where did you get that tile? I love it, thanks for the video.
I believe that was a 12x24 tile sold at Lowes, perhaps under their "style selections" house brand. It was a decent porcelain tile.
Shouldn't that gap between tub and tile bottom be more like 1/4" ?
I make that gap the same as the grout line spacing, which was 1/8" in this case. That looks best. If you've installed the tub or shower pan well, the movement is limited to the expansion and contraction of the tub material and perhaps some difference in seasonal movement between the wall and floor. That should be nowhere near the grout spacing. If you can actually see movement in the tub or pan when stepping into it, something is wrong.
@@enduringcharm I was just about to ask what the gap width should be thanks for the video.
1/8 “ big enough gap for caulk on fiberglass tub. Im a big man & the better 1/2 wants tile up & tub already moves & stress
Typically I use the grout line gap as a measure for the gap between the tub and tile. Make them the same. However, the tub really should not be moving enough to see visually. If the tub is installed correctly you should be able to stand in it and not see movement at the lip. Any movement should be very minimal with weight or with temperature changes.
I hung and finished drywall for over 40 years. The plastic is a NO-NO for me. In the south, North Carolina respectively back in the 1980's they would put 4 mil plastic over the insulation on all exterior walls of newly built homes. My crew & I would come in to hang these homes and everywhere the plastic membrane was there was also a pool of water at the baseplate, even in winter. After about ten years they found out that what some stupid engineer had glorified was actually a nightmare. Kind of like the cars they design now. None of these homes are still standing.
Your concern is partially misplaced. What you are referring to is a situation where you have either a double vapor barrier, or a vapor barrier in the wrong position in the wall cavity. Moisture needs to be able to migrate and not be trapped. But there is a key difference between that issue and what I do with the plastic. In my case the plastic does not cover the whole plane of the wall--it's only covering three feet of a 7 or 8 foot wall. It's not acting as a vapor barrier, only as flashing of sorts. Moisture can still migrate through the wall and not be trapped. Also, if any water were to get through the tile, grout or backerboard, it could only return back to the tub or pan, since the plastic overlaps the lip.