Elastomeric or liquid waterproofing membranes are one of the most convenient methods of waterproofing shower walls before installing tile. These membranes consist of products such as Custom Building Products’ Redgard and Laticrete’s Hydrobarrier and Hydroban and Mapei’s Aquadefense. I will refer to all the membranes as Redgard for the purposes of this post, but they all work nearly the same way.
These materials can be installed with a regular paint brush, paint roller, trowel, or even sprayed on. They are applied to your shower walls then tile is installed directly onto it. When I use these products I always use a cement-based backerboard as the wall substrate without a plastic vapor barrier.
It is imperative that you do not install plastic behind your walls since this would create two waterproof membranes with your substrate between them. Having two barriers this close together leaves open the chance of trapping moisture between them with no way for it to evaporate. This may lead to mold.You must also tape the backerboard seams with fiberglass mesh drywall tape.
The easiest way I have found to install Redgard is, after the walls are prepped properly, start with a paint brush and thoroughly coat all the corners and angles. The membranes are more the consistancy of pudding than paint so don’t be afraid to scoop it out to spread it. You should be used to it after a few minutes.
After all the corners are coated I use a paint roller and pan to cover the walls. Redgard is bright pink – I mean pepto-bismol pink, it almost glows in the dark. This is useful in that when it is dry it turns dark red. The other membranes are similar. Laticrete’s Hydroban, for instance, goes on light green and dries forest green.
Just thoroughly coat the entire inside of your shower until the whole thing is bright pink – enough so it can be seen from space. That’s it – go have an adult beverage until it dries. You must then do a whole second coat the same way. Make sure the first coat has fully changed color before applying the second coat. If you are using a roller Custom (the company that makes redgard) recommends that you roll on the first coat horizontally and the second coat vertically to ensure full coverage. (Thanks for that Davis)
Most of the product specifications for these materials state two coats to be sufficient, and it probably is. I normally use three coats. I’m weird like that. Unless you have a steam shower or something similar, two coats would probably be enough. It’s up to you.
These products shrink a bit as they dry so you must make sure that it has not shrunk enough to create holes or voids in places such as corners and seams. You need a full coating for the product to be effective. When you are finished you should let the walls completely dry for a day before tiling.
Your tile can then be installed directly onto your walls over the membrane with a proper thinset mortar. When these products set they will create a rubber-like coating on your walls that is waterproof. When used on shower walls it is a (relatively) quick, effective water barrier for your installation.
These products can also be used as waterproofing on your shower pans in leiu of a regular pan membrane. Make sure your specific product includes specifications for this application if you choose to do that. Check the respective website for your particular product. I do know you can do this with Redgard, Aquadefense, and Hydroban.
I also use these products for main or additional waterproofing on things like shower niches and concrete wall in basements, places where it is difficult to have a plastic vapor membrane behind the backerboards. Basically any place that does not have waterproofing between the tile and shower framing. I always have Redgard with me. The versatility of these products make them a integral part of my shower waterproofing toolbox.
The only drawback for these products, if you choose to look at it that way, would be the price. They are a bit expensive. You may be able to get better prices by ordering online but make sure you take shipping costs into consideration. You can get a gallon of Redgard online for about $45.00 plus shipping. That should be enough to do a regular tub surround. That is a five foot back wall with two 3 foot side walls. For larger showers you can also get a 3.5 gallon bucket.
Make sure to check the website for your product, they have a load of information for them. As always, if you have any questions feel free to leave a comment for me.
Need More Information?
I now have manuals describing the complete process for you from bare wall studs all the way up to a completely waterproof shower substrate for your tile. If you are tiling your floor and walls and using a liquid membrane you can find that one here: Liquid Topical Waterproofing Membranes for Floors and Walls.
If you are just tiling around your tub or pre-formed shower base you can find that manual here: Liquid Topical Waterproofing Membranes for Shower Walls.
Hi Roger,
Love the blog, thanks so much for doing it!
I am planning on a stone veneer wall in a shower. Ive seen both cement board and metal lathe installations. Since it will be in the shower area I am of course concerned about moisture.. Ive thought about the cement board with redguard but that probably wouldn’t work as the mortar needs to bond. What are your thoughts?
Thanks in advance!
Chris
Hi Chris,
What mortar needs to bond? If you are doing a traditional stone veneer (lath, etc.) then you can not use redgard in that application. You can, but it would be rendered moot when you install the lath. If you are just installing your stone veneer with thinset then it will bond just fine to the redgard.
Roger, question about Redgard and modified vs unmodified thinset. Would Redgard slow the curing of modified thinset (which requires air to cure) when using 12 X 24 tiles? Unmodified thinset which requires moisture to cure will not be robbed of the moisture because of the waterproof properties of Redgard. I am so CONFUSED!! :
Hi BJ,
The ONLY time to use unmodified thinset is over schluter products. Redgard is chemically manufactured to work with modified thinset – no matter the size of the tile.
Roger,
I’m using Redgard and as part of my tile install I want to start off with a ledger board. Can I screw the board thru the Redgard membrane, then when I’m finished just patch the holes and spot brush Redgard and have confidence that I’m still going to be waterproof?
In the future, if there is a plumbing issue and I have to break thru the Regard membrane and get inside the wall, can Redgard be patched and still keep waterproof integrity?
Hi Dennis,
Yes to both.
Am tiling a shower with 12×12 tiles over cement board with Redgard applied. I am using a polymer modified thinset.
Question: how long should I wait to grout? I have always heard 24 hours but have read that because of the Redgard being applied the wait time should be increased.
Hi Mark,
24 hours.
Roger,
I am replacing my fiberglass shower (now removed, of course) with glass a tiled enclosure. I have put in the cement pan and liner and the walls are now cement Hardibacker and taped with thinset over the joints and corners. I am planning on putting on Redgard for the walls and the issue I am having is the type of mortar to use with the Redgard/glass tile combination. I was told by one manufacturing authority to use epoxy mortar because it will not shrink and crack the glass tiles (4″x8″), but most seem to be saying use to use a modified thinset mortar to attach the tiles over the Redgard. Any thoughts?
Also, since the floor pan is a combination sandwich of cement mortar/vinyl liner/cement mortar, is there any additional benefit or detriment from rolling the Regard on the shower floor also?
Thanks, Peter
Hi Peter,
Regular modified thinset is what you want over the redgard. And you do not want to cover your floor with the redgard when you have a liner under it – it’ll create a mold sandwich and your weep system will not work correctly.
ohhh what a mess I made… I was applying redgard to the walls and I spilled the 3.5 gallon bucket on my cement floor (wich I didn’t have covered with anything even though I knew better). I didn’t know what to do so I scooped up as much as possible then smoothed out the rest as best as I could. I have a pvc liner installed and I know I am not supposed to redgard the floor with a liner, the whole floor is 42″ x 96″ and the spill is covering about a 2′ x 3′ area, is this as bad a I think it is or will I be ok since its not the whole floor?
Hi Craig,
It should be fine. Drink beer AFTER you tile.
we gutted our main bath and are now installing the tub/shower combo. I read about Hydro Ban, went and bought some, and will be applying it after the cement backer goes up. Questions :
1. Any specific type of tape and/or joint compound that should be used?
2. How long does joint compound usually take to dry,and how long before I can apply Hydro Ban to the cement backer?
3. Thinset or tile mortar? And is there a specific type that needs to be used with Hydro Ban?
Any other tips or advice would be appreciated!
Thanks
Hi Susie,
1. Alkali-resistant mesh tape sold in the tile section. Thinset, not joint compound.
2. DO NOT use joint compound, use thinset. 24 hours.
3. Thinset is tile mortar. Unless you’re talking about the ‘premixed’ thinset or tile mortar, in which case – DO NOT use that. Modified thinset for use over hydroban.
Roger,
I will be installing engineered marble (fake marble) slabs as my shower walls…underneath those slabs will be durock cement board. The company that’s fabricating and selling me these slabs recommends using silicone to adhere the panels to the cement board, will silicone stick to redgard ok?
Thanks
Hi Sam,
I don’t believe that would last long term. I would definitely use thinset for that.
Roger,
Thank you for your time and dedication help all of us.
I am redoing a small hall bath that had a plastic corner shower kit: ABS injection-molded wall panels and a one-piece plastic shower base. The existing floor is ceramic tile, which we are not changing. The shower kit walls were adhered to the drywall, which has been ripped out. In order to not have to deal with changing the drain rough-in, we purchased the same shower kit simply to use the one-piece shower pan. The shower base is about 6″ tall at the curb and has a 1″ flange, and it is meant to be installed over drywall, held in place nailed to the studs through the flange and by the drain connection around the PVC sticking up through the slab. We are going to tile the walls.
The drywall is 1/2″ (still some left on the left wall and right wall that will butt up against the backer board). I purchased 1/4″ Hardi backer board because I though it would be easier to work with than 1/2″. I also bought wood lattice strips (a little less than 1/4″ thick), and drywall shims to be able to bring the backer board to the same plane as the 1/2″ drywall. I have a few questions.
1. Should I return the 1/4″ backer board and use 1/2″ backer board instead?
2. I’m concerned about how to seal the intersection of the shower base flange and the backer board, and the 6 to 7″ of exposed studs below where the shower pan meets the wall studs where there would be no backer board. I was planning to staple 6 mil plastic to the studs from the floor up a few inches past the top of the shower base flange, and installing the backer board down to 1/16″ to 1/8″ above the top of the shower base flange and fill the gap with silicone. I am planning to coat the backer board (field and cubbies) with Redgard.
Should I put the plastic sheeting behind the pan like I’m thinking or just leave it open, presuming I am going to get a good seal at the flange-backer board joint?
3. When I install the tile, how far down should I bring the tile? If there are screws through the flange into the studs, both aesthetically and performance-wise, I think I want them covered, but the flange is not as thick as the 1/4″ backer board, so there will be an uneven surface, so how can I tile that? FYI, there are no pre-drilled holes in the flange, and notably, whoever installed the base before didn’t screw it to the studs. It was just the drain connection, and caulk at the panel joint, holding it in place. Do I need to shim out the base so it is even with the backer board? Even if I get the backer board and flange in the same plane, will thinset even stick to the shower base? Should I just use silicone caulk instead of thinset there, knowing that there may be some minor movement when someone steps onto the shower pan? How far from the bottom of the flange should I end the tile – just enough to go a little past the screws?
Thanks for your help!
Hi Erik,
1. Yes.
2. Silicone the back of your backer to the flange, then redgard all of it. Provided you do that you don’t need to worry about the studs at all. No need for the plastic.
3. Thinset will not bond to the acrylic. The flange should be behind the face of the backer, the tile just hangs over it and comes down to within 1/8″ or so of the horizontal portion of the base.
Hello, I am getting ready to do my first tile shower job. Floor, ceiling and walls. The contractor that helped me frame it up used the purple gypsum drywall and said we would install the hardibacker over the walls and just put the tile directly on the ceiling since it would be above the water area and would only be susceptible to water splash. Now as I get ready to start the job, the more I read the more I get confused. I am hopeful that you can answer some of my questions and appreciate any feedback/direction you have.
1. Is it safe to put the 9×12 tiles on the purple drywall ceiling? If not, it’s going to be tough b/c it’s glued and screwed and will be hard to remove. I thought about just adding hardibacker on top of the ceiling, but 1-5/8″ screws seem to be all I can find (unless I can use a different kind of screw).
2. For the floor, he put in a fixed drain (wishing it was adjustable, but I think I have about 5/16″ from concrete to bottom of drain. I am going to build my slopes and purchased Mud Bed Mix from Lowes today. Is this mud bed compound fine to use to create my floor slope?
3. Is it ok to put the hardibacker over the purple drywall on the walls?
4. Should I put Hardibacker up before I do the floor bed or run the hard to the concrete floor and then float in the the floor bed?
5. Once the hardibacker and floor are in, is it okay to red guard the entire shower (floor, walls, and ceiling)?
Sorry for so many questions, but I really do not want to screw this up.
Hi Brian,
1. Yes. But it would be better to remove the board and replace it with backerboard.
2. It should be, but I don’t know exactly what ‘mud bed mix’ you have.
3. No. I don’t understand the reasoning behind that.
4. You should put it up after you have the mud beds in.
5. It depends on whether or not that is your waterproofing method. If you have a liner in your shower floor then no, you shouldn’t use it there. You should use it on the walls, but the purple board has to go.
Hi Roger,
Two questions for you.
Vinyl pan liner with hardi backer.
Poly behind the backer.should I red guard only the seams and corners? Didn’t know about the poly at the time. Will the walls be OK without the r.g., should I only go 1/2 way up.
Please describe how to start tiling the walls. Bottom up.
Thank you very much,
Dennis
How
Hi Dennis,
You should redgard none of it if you have poly behind it. Seams and corners will do you absolutely no good.
A bit confused about your tiling questions. Install the bottom row, then install the next row, then install the next…
Hi, I’m so glad I found your blog!
Here’s a question I haven’t found an answer to yet: What will happen to the adhesive properties of the thinset used to apply the tile if I patch my existing drywall using joint compound and fiberglass tape, then coat it with RedGard?
Thanks!
Hi Patricia,
If you’re doing this in a shower then your dog will burst into flames, but nothing will happen to the thinset. Moisture in redgard can cause the regular joint compound to dissolve, leaving a void under your redgard. That’s never good. Drywall is not a proper substrate for tile or redgard.
Thanks Roger! You helped me avert a disaster!
Plan B: Denshield glass mat tile backer (requiring no Redgard). Have you used it?
I’m doing this myself and hoisting a 45 pound cement board while securing it to the wall is just not gonna work.
Hi Patricia,
Yes, I have used it. It’s good stuff. I have a manual for that as well – it’s topically faced wall substrates.
Hi Patricia,
Yes I have used it. It’s good stuff. Just make sure you seal the penetrations and seams.
hi Roger , got a question for you , hope you can help me.
i have striped a shower recess , had white ants problems , installed villa board to 3 walls and then proceeded to fibreglass all 3 walls and the floor pan , the floor pan was originally tiled , however i removed those first.
do I need to apply a coating of something before tiling . the corners and floor to walls had 2 coats of fibreglass..thanking you..michial
Hi Michial,
You should have deck mud over the fiberglass on the floor, and your wall substrate should be over it on the walls. Tile bonds directly to those, not the fiberglass.
Hi Roger, I hope I didn’t just miss the post somewhere and am wasting your time, but is there an advantage to doing the traditional method for a shower pan over the single layer method with Redgard? It seems most people use the traditional method but the single layer seems to save some time and energy.
Hi Levi,
A topical waterproofing is the most efficient. The main reasons people still do traditional are the cost difference (cheaper) and/or lack of knowledge/information/ability.
Hi Roger, My contractor has just finished our new master shower retile, but I’m in a state of panic! We had prepurchased Redguard for him to use as our waterproofing membrane, which he agreed to do.Towards the end of the project (silly me) I decided to read the Redguard instructions and realized that what he did was nowhere near what they said to do. What he did was paint on a single thin coating with a paintbrush. Our shower is completely tiled now with a variety of specially ordered tiles and we are awaiting the frameless door, but I am not getting very much sleep! Our reason for retiling in the first place was moldy tiles. Should I expect to retile again soon?
After surfing your site, I wish my hubby and I would’ve attempted it ourselves.
Thanks for enlightening us.
Hi Fay,
It may be fine, it may not. No way to tell at all. I can’t guarantee a failure, I can only suggest methods that guarantee success. I would document everything you can so if you do begin to have problems you have proof that it was incorrectly waterproofed. For what it’s worth you’ll likely be fine unless the redgard was used as the floor membrane as well, in which case I would begin the process to have it replaced immediately. While the walls can be fine with a less than adequate coating thickness, the floor will not be.
I think I F’ed up. Yesterday I watched a utube that said to use the same material that you will use to attach the tiles as the “mud” you use to anchor the alkali free joint tape. So I bought Redgard and Omnigrip “maximum strength adhesive”. I taped the Hardibacker and put a layer of the Omnigrip mastic over that (including all around the niche). Today, I decided it might be a brilliant idea to actually read the directions on the Redgard tub. Sure enough at the very end it said to use polymer modified morter and not to use tile adhesive. And of course, it was then that I stumbled across this informative site. Then I called the Redgard people at Custom and a supervisor finally said the Redgard would stick to the Omnigrip, but not really well and they wouldn’t guarantee it. He said I could take a chance but the better option would be to tear out the Omnigrip. Flip a coin he said. I then used a putty knife to try and free some of the tape. Basically no go. It’s like trying to scrape 30 square feet of construction adhesive off of plywood.
So the question is, have you ever attempted to apply Redgard over mastic on cement baord tape? Also, do you think applying water to the mastic repeatedly might loosen it so I can start over with morter?
Hi Carl,
No, I have not, but I don’t use mastic. Here’s a better option: (he was correct, btw, it’s nice to hear an actual answer from tech support ) Skim coat over the mastic with thinset, let that cure, then paint your redgard in the shower.
being from the “old school era” we never used red guard on walls or floor is this something new and how necessary is it…….also would mold type drywall work this days for bathroom shower walls.
Hi Jose,
Redgard has been around for about thirty years. It was initially created as a crack-suppression membrane. Something behind your shower wall tile is necessary to waterproof your shower, it doesn’t need to be redgard, but something needs to be there. When we did mud walls the combination of the cement layer with tar paper behind it waterproofed the walls. New products don’t have the ability to utilize the water in the cement mix like mud walls do, that water needs to be contained and controlled.
While there is drywall that states it is water or mold resistant, neither will waterproof your shower nor hold up long-term behind shower wall tile. The closest you’ll find it a product like dennshield, which is a water-resistant gypsum core with surface waterproofing membrane right on the board.
I have found your site very useful and the waterproofing manual I purchased has been a great value and invaluable. I do have a question for you though, after I hung the Durock the sheet rock team came in and used sheet rock mud to level out parts of my shower (don’t ask me why!) Since I’m going to be using the waterproofing membrane method can I just Sand down the sheet rock mud and paint the membrane over-the-top or do I need to remove it completely?
Hi Kymv,
You can sand it down, apply one layer over the drywall mud, let it cure, then install it in the entire shower as usual. The drywall mud will suck moisture out of your membrane, so you want to have the additional initial layer on there to ‘prime’ it. Other than that you’ll be fine.
I’m so glad i found this website as I am a complete first timer when it comes to anything construction. I decided to remodel my bathroom and this site has helped so much. Thanks to all of you
Hi Roger,
I am installing acrylic shower walls with a shower base pan. Would this same process be needed to create a vapor barrier or is there a different process?
Thanks,
Matt
Hi Matt,
There is no process, the acrylic sheets are your waterproof barrier. They go right to the studs.
Question! I am remodeling a basement and am about to start on the bath shower area. The shower had existing tile that was in horrible condition so it was removed. Underneath is just masonry type bricks as the frame for the shower (square). Can I use the RedGard over the bricks then tile directly tile over it? Or should backer board be installed regardless?
Hi Mark,
Yes you can.
Hey – love your site. Have a few questions.
Customer wants clear glass tile (1″x3″) on the shower walls – this poses some questions and concerns.
1) I see that most glass tile needs modified thinset (I am still waiting for a reply from this specific tile mfgr for installation specs, but I am assuming they will recommend modified). This rules out my favorite – Kerdi (right?). Can you suggest a topical membrane that I can use in conjunction with glass/modified thinset?
2) Since the glass is clear, is using a white thinset enough to ensure that the color membrane won’t show through? Do they make a white topical membrane?
3) Do you have a manual about cutting this stuff. The last glass tile I used was on a back-splash and the typical wet-saw I used cracked the tile, made lovely skin cutting glass shards, and the cut edges were rigid.
Any help is appreciated.
Thanks,
Kane
Hi Kane,
1. You can use any of the liquid membranes. Correct, you should not use kerdi.
2. They do not make a white membrane. I will normally skim-coat the membrane first, let that cure, then install the glass.
3. I do not. I use my Sigma to cut most glass tile, not a wet saw. If you use a wet saw you should get a glass-specific blade for it.
As an aside: Clear glass in a shower is not really a good choice. Since water WILL get behind your tile you will be able to see it. ALL thinsets change shades when wet. The wetter parts of the wall will show through and there will be a ‘line’ of water similar to looking at water trapped between two panes of glass. It will dry out, it’s normal, but it will be seen. I would absolutely ensure your client knows that before moving forward, it will also cover your ass when she calls and says ‘my shower wall is turning different colors (shades)’.
Dude, your awesome. Very educated/experienced.
I showed the customer your reply about the clear glass tile, and considering the area we are in, where the water is less than clean, it makes sense to avoid a glass tile where the thinset will be visible and thus eventually stained – they are appreciative (as am I) of the information and are reconsidering the tile selection. I am checking to see if the original choice is actually clear or if there is a backing of sorts to prevent this issue.
Some more questions if you don’t mind….
1) Hydro Ban vs. Hydro Barrier vs Redguard?
2) Durock vs. Hardibacker. I prefer Hardibacker due to it’s moisture resistance, but I ran across a website suggesting that it was inferior and didn’t work well with liquid membrane?
3) Where the liquid membrane meets the tub surround – will the membrane stick to the fiberglass? I would think that there should be a 1/8″ to 1/4″ overlap between the backerboard and the fiberglass flange.
4) Transitions to the sheetrock. Is it Ok to have the membrane extend past where the tile will go? Will spackle/paint stick to the membrane – or should we stop just shy of the tile edge?
5) I have browsed your library and have found lots of publications I would like to purchase, however it seems that they are very specific. Do you have just one big book or bundle that covers just about everything? If so, please direct me to it/them.
Thanks again
Kane
Just a couple of notes from the peanut gallery – – I did my first glass tile work about a month ago. The key was buying a blade specifically made for glass, and cutting slowly. I found that cutting in 2 passes was best to avoid chipping: the first pass is shallow and slow to score the visible surface, and then turn it over to complete the cut through from the back side. I then used a file to graze the cut edges to ‘soften’ the sharpness.
As far as seeing through the glass to the mortar, membrane, etc – – [note: I have only done this once, and did not research far and wide, so my experience is very limited] All the glass tile I found actually had an opaque film on the back side, which gave it its color – – in fact, although the glass looks colored (like stained glass), it is actually just clear glass with the colored film on the back side. “Clear” looking glass tile just has a white film on the back side. If your client is actually looking at glass tile that you can see through like a window, perhaps you could steer them to the kind with the film on the back. I see no useful benefit to see-through tile … they will only see the setting materials … (why?!)
Hi Kane,
1. They all work well. I prefer them in the order you listed them.
2. The also both work just fine. Hardi is better and cleaner in my opinion. You’ll always find someone on the internet who hates a product, tile products are no different.
3. Yes, it will bond to the acrylic or fiberglass.
4. Yes, and drywall mud or spackle will bond to it, but paint won’t (unless it’s first covered with the aforementioned spackle or mud). I would stop shy of the tiled edge.
5. Each manual does cover one specific method so no one gets overwhelmed when trying to tile their own bathrooms. If you want the entire collection email me at Roger@FloorElf.com and I’ll send you a link where you can purchase them all at once at a lower price than individually.
Hi Roger, when using Redguard on backer board, regarding the joints (both within a plane and at the corners, do you start with a gap between boards, then tape it with standard drywall fiberglass mesh tape (not the alkali-resistant kind), then apply the Redguard? That is, you don’t first have to tape and bed the joints with thinset, right?
Hi Joe F, I’ve been reading Roger’s blogs and E-Books for about 2 years now and I think Roger will back me up on this correction to your proposed materials and methods you are asking advice on above, so here goes.
Hopefully you haven’t taped and mudded yet as you really do need to use the alkali-resistant mesh joint tape, NOT the standard fiberglass mesh tape, as the regular stuff doesn’t hold up very long when the modified-thinset reacts on it (too acidic I think).
I have just been taping over the 1/8 gapped durock or Hardibacker substrate boards flat joints and then mudding over that with Modified Thinset, while just pressing hard as I mud and that will push the thinset through the mesh to fill the 1/8′ gap, without having to first pre-mud the joints before applying the mesh.
Also, you don’t want any thinset in the change of plane (corner) joints. Fill those flush with 100% silicone (this will keep the thinset out), then let that set up a bit, and then use the alkali-resistant tape folded in these corners with modified thinset feathered out over the mesh tape. Then let all that set for 12 hrs or so and go on with your liquid waterproofing. You may?? also need to use a wider (5″) reinforcing mesh in your corners along with the liquid waterproofing application depending on what the manufacturer wants. It will take 2-3 coats of the liquid waterproofing to achieve the proper consistent thickness, I think Roger says the thickness is about the thickness of a credit card or a bit more, and will achieve that in 2-3 layers using the manufactures recommended drying time between coats.
What do you say Roger, did I state it correctly (but probably using 5 times the space you could write it in, huh?)
Hi Bob,
You’re hired!
Well stated, thank you. You can, however, also use unmodified thinset, not that you would when using redgard, but I thought I’d throw that out there because SOMEONE is going to ask.
Hi Joe,
You do have to tape and bed the tape first, let that cure, then paint your redgard over them. You still need to tie the boards to one another, taping and mudding them first is how that’s accomplished.
Hi Roger, when figuring estimated total thickness of a finished wall, what is the nominal thickness of the thinset? (context: 6″x24″ wall tile, 3/8″ thick on Kerdi board) Thanks again, Jim Spurr
Hi Jim,
It will be half the size of your trowel notch. If you are using a 3/8″ trowel your thinset bed will be 3/16″.
Great site, Thanks.
I am replacing an old tub with a shower. I have concrete floor, one concrete wall, and 2 wood walls. All walls have paint on them. I am planning on gluing vinyl sheets on the walls. I would like to color my concrete and seal it for the floor.
Can I use redguard on the existing concrete floor and a few inches above the floor to sufficiently water guard it?
Will the reguard go over the paint on the walls?
Will the glue I use for the vinyl walls stick to the redguard?
I plan on using bath calking to seal around the floor between the concrete and vinyl. Think it will work?
Hi Lisa,
You can use the redgard, but it won’t sufficiently safeguard it without the proper slope, drain, etc. I know nothing about stained or colored concrete for a shower floor. The paint on the walls needs to be removed for successful redgard installation. I have no idea what type of glue you’re using for that, so I don’t know if it will bond to redgard or not. The caulk will work for a (short) while.
I am a professional tile contractor – none of your questions deal with tile. Sorry I couldn’t be of more help.