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Question for Bill or other expert about Redguard waterproofing

Posted by lenitsa (My Page) on
Thu, Aug 31, 06 at 22:22

Bill,

Hope you recall I posted the whirlpool / shower question. My GC has purchased Redguard or some version of it that you recommended. But the tile store that supplied it is telling him he should apply the Redguard then a physical membrane, then thinset and tile. I thought the dried Redguard was the membrane. I'm so very confused. He has installed cement board all around the whirlpool tub. He will give me the final word on it, but insists that cementboard plus some epoxy he adds to the grout will be waterproofing enough. And as I stated earlier, the tub is in. So, I am trying to make the best of this situation. Please .. please advise. Thank you


Follow-Up Postings:

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RE: Question for Bill or other expert about Redguard waterproofin

The Redgard IS the membrane. I'm not sure what he's talking about, unless he's talking about a fabric that can be imbedded in the Redgard. As for his statement about putting "some" epoxy in the grout, now, I'm skeptical. Either he's using epoxy grout, or he's not, and if he's not, he can't put "some" epoxy in the grout. He must be talking about a latex additive, in which case, he's COMPLETELY off base. Even if he uses epoxy grout, there's no guarantee that the installation will be waterproof, and he's taking a huge risk with your bathroom making that claim.


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RE: Question for Bill or other expert about Redguard waterproofin

Bill,

Thanks so much for your reply. You are AWESOME! Now I have it straight in my mind.

-Leni


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RE: Question for Bill or other expert about Redguard waterproofin

We were advised to place Redguard waterproofing on backerboard before laying slate tiles on our outdoor entry landing and a small balcony. We did that, and 2 days later it rained. To our dismay, the stuff turned to mush!! It seemed dry before the rains. Is it supposed to cure longer?? We'd appreciate any further advise...
Thanks!!


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RE: Question for Bill or other expert about Redguard waterproofin

You might want to check the bag of REdgard-- I don't believe it's approved for exterior use, but that still shouldn't have "turned to mush". What exactly turned to mush-- the redgard itself?


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RE: Question for Bill or other expert about Redguard waterproofin

The RedGuard Tub does state that it is meant also for use on "exterior decks" The substance itself re-melted, if you will, into a liquid with the rains. I re-coated a week later - It seems to require a longer curing time overall?? Hope that'll do it, but only another rain will tell...
I've worked with other elastomeric membrane roofing compounds which seem to go on thicker and not require so many coats, which says to me that RedGuard may not be the best way to go if you're really looking for waterproofing? Have you used other elastomeric membranes??


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RE: Question for Bill or other expert about Redguard waterproofin

I've used several membranes of different types. From the old formula of hydroment's Ultraset (I wouldn't use the new formula outdoors-- I don't trust it as much as the old stuff) to reinforced bituthane membranes like Protectowrap and ECB. The best one I've seen though, is a sheet membrane that's made specifically for exterior installations from Noble called Nobledeck. It's a bit heavier than other sheet membranes and will take alot more abuse. One other good thing about the sheet membranes-- you can install them over everything and then thinset the tile directly over the membrane, thereby making sure the entire subdeck stays nice and dry.


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RE: Question for Bill or other expert about Redguard waterproofin

I am in the process of building a balcony. The floor of the balcony is made of 3/4"OSB nailed into TJIs and has a 1/4" per foot drop away from the house. A diamond saw cut was made into the stucco just above the floorboards (where the floor meets the stucco wall on the back of the house) to admit a Z-section flashing resting over the plyboard. The flashing was sealed with roofing compound 700 towards the stucco. Then a layer of bituthane was placed over the plyboard. This was covered with a layer of 7/16" OSB nailed 6" on center into the floorboards. The OSB was primed with Sherwin Williams primebond. A layer of thinset was added on top of all this which seemed to hold; however, over 6 months of weathering and recent rains the layer of thinset is cracking and peeling off. A consultant at Custom Products (makers of Versabond) suggested covering the floorboards with backer board over thinset and apply Redguard over the backer board for waterproofing before attempting to lay tile with Versabond thinset mortar containing latex on top of all this. After reading commentary at your website, I am skeptical of the redguard. I'd like to use a polyethylene membrane (like Schluter's "DITRA" or "KERDI"however I have not found anyone who sells this stuff). What should I do? What would you recommend?

Also, will the layer of OSB sandwiched between the backer board and bituthane turn to mush or get moldy over time if I cover the top with a waterproofing layer (which I must)???

I'd appreciate a reply ASAP. Thank you!


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RE: Question for Bill or other expert about Redguard waterproofin

First, I'd be leary of the bituthane layer as bituthane can compress. I also would NOT trust Redgard in an exterior installation. If it were me (and I'm assuming this will be tiled?), I'd have two layers of plywood instead of OSB, screwed, NOT glued together. Then do your flashing, and then I'd be using a membrane from Noble made specifically for exterior installations called Nobledeck. Over the Nobledeck, you can directly set your tile-- the thinset will bond to it.

(look down around the bottom of the page in the link below)

Here is a link that might be useful: Noble Sheet membranes


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RE: Question for Bill or other expert about Redguard waterproofin

Hi, I was told to use the redgaurd to seal the seams in the backerboard for my tile shower stall, and also to seal the floor slab with the same product. I was also advised to use only a polymer re-inforced thin set to lay the tiles, does this sound right?


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RE: Question for Bill or other expert about Redguard waterproofin

Sealing seams doesn't really do anything for you, being thst the rest of the backerboard isn't waterproof. As for sealing the slab, Didn't they put down any kind of membrane UNDER the mud floor? Or is this the same concrete slab as throughout the rest of the bathroom?

One way or another, something doesn't sound kosher here. About the only thing I see that I agree with is the recommendation for thinset.


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RE: Question for Bill or other expert about Redguard waterproofin

Yes, there is a layer of the redgaurd under the mud that was set in today. I mixed the mud myself using a 4 or 5 to 1 ratio of sand and cement. The slab is the same for the whole house. What I did was seal the perimiter of the shower floor including the curb with 3 coats of the redgaurd. The I layed in the mud and am now waiting for that to dure so i can lay the floor tiles. What did you mean by the backerboard is not waterproof? As far as I can see I have sealed everywhere that water might seep through. And once the tiles are layed they will be sealed properly as well. The last thing being that where I am(Las Vegas) is a very very dry climate and mold is not a huge problem here. But either way, I think I have taken as many steps that I can to be sure water does not reach the wall studs. If you think I missed something, please let me know. I am a novice but an trying to do my best to get it right. Thanks!


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RE: Question for Bill or other expert about Redguard waterproofin

There's atleast three MANDATORY steps that I can see off hand that weren't taken. The first is that there needs to be a vapor barrier behind the cement board. THAT'S what keeps moisture out of the wall cavity. Although the tile and grout will shed water, they're not waterproof, especially the grout-- even if you seal it. Most sealers are "breatheable", meaning they allow vapor transmission back and forth, so as to allow subsurfaces to dry out.. The vapor barrier (usually either 6 mil polyethlene or 15 pound tar paper) is what keeps the moisture from getting into the wall cavity, and giving mold a chance to get its start. Which brings me to my next problem-- by using redgard as your pan membrane, there's no way to tuck the bottom of a vapor barrier inside the pan membrane, so that any moisture it catches will roll down into the shower pan, and down the drain.
NOW-- there IS a remedy to this, and it's a relatively easy one, and that's to coat the entire walls of the shower with Redgard, right up to the showerhead. Then you have a completely waterproof envelope. I personally don't trust Redgard as a waterproofing for the pan membrane, but this isn't my shower, either.

Now comes the one thing that CAN'T be rectified without backtracking and doing a little ripping and tearing, and that's something called "preslope". it's just as important that the pan membrane gets sloped as it is that the tile itself gets sloped. Otherwise, the water that gets into the mud in the shower pan will sit there, rather than going to the weepholes at the bottom of the drain. If the membrane is sloped, all water will drain, and the pan dries out. Lack of preslope can cause a real problem with bacteria and mold INSIDE the mortar under the tile.


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RE: Question for Bill or other expert about Redguard waterproofin

Bill,
If my contractor has never used Kerdi or Ditra should I ask him to use it? Is it hard to learn?
Donna


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RE: Question for Bill or other expert about Redguard waterproofin

Donna, either one is about as simple as it gets. I'm going to post a link to Kerdi's web page. On it is a streaming installation video. Believe me when I tell you, it's as easy as he makes it look in the video (might take a bit more time, but just as easy!) Kerdi and Ditra are about as goof proof as you can get. Matter of fact, the first time I used Ditra, I'd never even seen the stuff-- only ehard about it. I sat down for about 15 minutes, read the directions, and the rest is history. It's really that simple.

Here is a link that might be useful: Schluter Kerdi


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RE: Question for Bill or other expert about Redguard waterproofin

Saw some red guard at Home depot today, from what I gathered it is a one part product, I would guess it is considered a non mixing epoxy, sort of like trying to have a premixed wet mastic instead of water activated powdered thinset,.... this is not as good.
I think there is a good alternative, and that is to use epoxy instead of red Guard. A quality epoxy will actually get hot as it is activated, and turn into a solid like plastic. It will not shrink at all if it is 100 percent solids epoxy, so basically you are left with a slightly rubbery plastic. (slow set is rubbery and stronger, fast setting is more brittle little weaker but any "heat activated" epoxy I would think is going to be fantastic for a moisture barrier. So why does'nt anyone use it? expense? I have'nt heard anyone at the John Bridges forum using it......my guess is expense.
Long story longer I have 3 gallons of the stuff (quality genuine epoxy)coming in the mail for other reasons while I am re doing a bathroom, and I want to know if I can use it on top of the cement wonder board - you know, just skim some thinset on the board to fill in the little epoxy eating voids, and finally skim a thin skin layer of that expensive epoxy over that to stop the moisture before it gets to that wonderboard which is basically a big sponge otherwise.
Incidently, I bought this epoxy for 69 dollars for one and one half gallon, it is a non blushing epoxy which means it does not form a waxy layer on it's surface as it dries (which would be undesirable) so if you want to try some type Bio Vee sealer in google and go to the website "epoxy products" or somethingother. I use the stuff for everything, works great with fiberglass for stubborn dry wall cracks.
Last question is in the inside or outside corners using cement board such as wonderboard, must the corners be expansion type with specific gap or are they to be taped and thinset with plenty of thinset jammed into the inside corners for something rigid/glued? ..or seen differently since I will be using laticrete flexible caulk instead of grout on all inside and outside corners for the TILE, should I then also use flexible caulk down thier at the CEMENT board layer in the corners??
I think because I am using a quality non blushing epoxy the versabond will adhere to it....maybe I will just have to do a little test piece of cement board versus cured epoxy and see if a tile with versa bond will still stic......

....actually what I really want to do in the shower inside corners is use strong 8 ounce fiberglass and epoxy


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RE: Question for Bill or other expert about Redguard waterproofin

All I'm going to say here is don't try and reinvent the wheel. What you're trying to do may or may not work. Redgard isn't, and was never even insinuated, to be an epoxy, or anything like it.

One other thing-- if you think expense has anything to do with why we do or don't use certain products, then obviously, you haven't spent very much time over at John's site. Every one of us only use the best products available to get the job done correctly.


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RE: Question for Bill or other expert about Redguard waterproofin

I am in the process of building a combination shower / steam room in my basement. The room is framed and rough plumbing installed. I was planning on lining the (level) concrete floor with a CPE or PVC liner then covering with 1-1/2" to 2" of concrete sloped at 1/8" per foot toward the drain. My intention is to cover the walls and ceiling in concrete backer board then coat the backer board with red guard to create a vapor barrier before tiling & grouting.

Now for the questions: Will red guard provide the vapor barrier needed to keep the steam on the inside of the steam room?

If I put 6mil plastic on the studs then add backer board and treat with red guard, wouldn't that be a trap for water (between the 6 mil and the red guard)? This assumes that moisture would get passed the red guard. If moisture won't go through than there no issue and no need for the 6 mil plastic.

I thought the floor was OK but after reading your post about a flat shower pan creating a breeding ground for moisture between the pan and underside of the tile I am concerned. How can I get the PVC material sloped to avoid the scenario you describe (it will be placed on a flat concrete floor)? Would I be better off without a barrier on the floor allowing any water that gets through the tile to pass through the concrete into the ground?

Any help would be greatly appreciated.

Thanks and sorry if this message is repeated - I was having trouble establishing an account.


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RE: Question for Bill or other expert about Redguard waterproofin

I just got through with my shower redo. I placed backerboard on the walls and ceiling. Then I placed a thick red rubber pan membrane on the shower pan floor and up the sides about 8 inches or so. The shower pan was already mudded previously with the slope to the drain. I placed fiberglass webbing over the seams of the backerboard. Then I took Redgard and painted it all over the backerboard and at all the seams and along the edges of the thick membrane - making sure to coat all the walls and seams real well and not skimping on the amount used. then I let it dry over the weekend. It is pink when you paint it on and it turns red when it drys - (or maybe visa versa) it does take a while for it to dry. And the instructions say to let it dry completely. then I painted on a second coat and let it dry for a week or so - it being winter and the rainy season I thought waiting would be better due to humidity in the air. My shower is 3x5 and it took almost two tubs to get it coated twice. When it drys it looks like a thick membrance of plastic and it sheds water - personally I think the stuff looked good and I feel it will work and I think it is much better than just putting the tile over the backerboad without it.


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RE: Question for Bill or other expert about Redguard waterproofin

I was planning on lining the (level) concrete floor with a CPE or PVC liner then covering with 1-1/2" to 2" of concrete sloped at 1/8" per foot toward the drain.

Needs to be 1/4" per foot.

Will red guard provide the vapor barrier needed to keep the steam on the inside of the steam room?

Although I'm not positive I believe that Redgard is a waterproofing, but NOT a vapor barrier. I've never used it, so I can't be sure, but this is definitely something to take into considedration. Before I started doing all steam showers in Kerdi, I was using Hydroment's Ultraset, which is BOTH a waterproofing as well as a vapor barrier.

Now, there's a slight flaw in your logic. You need to have a continuous membrane that envelopes the entire shower, floor, walls, and ceiling. In other words, either you're going to have to seal whatever membrane you use to the floor liner, or you'll have to also seal the floor with that membrane, as well. This is the biggest reason why it's so easy just to use the Kerdi system and be done with it. It's as goof proof as it gets.

How can I get the PVC material sloped to avoid the scenario you describe (it will be placed on a flat concrete floor)? Would I be better off without a barrier on the floor allowing any water that gets through the tile to pass through the concrete into the ground?

ABSOLUTELY NOT!!! You NEVER go without a membrane!! You need to float BENEATH the pan membrane as well as above, to CREATE that preslope. Below, use a wet mud, so as to be able to float from nothing at the drain to whatever height at the perimeter that will give you 1/4" per foot minimum. Again, the Kerdi system make this a whole lot easier because you only have to float a single time, being that the membrane goes on TOP of everything

springvillegardens-- you also may have issues with the way you constructed your shower. The liner should have gone BEHIND the cement board.


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RE: Question for Bill or other expert about Redguard waterproofin

Thanks for the quick reply and all the good information. I was unaware of the Kerdi system but just checked it out on-line and am very interested.

This is quite new to me but if I understand you correctly I need to float a concrete floor sloped at 1/4" per foot for drainage, placing the Kerdi material directly on top of the newly floated concrete, followed by thin set, tile and grout? No other steps?

Kerdi seems to create the exact barrier I'm looking for. Given that it is waterproof, couldn't I build the shower out of drywall and the apply Kerdi directly to the drywall (i.e., studs, drywall, Kerdi, thinset, tile, grout)? Would drywall be strong enough behind tile for support, or am I not understanding the function Kerdi serves?

Lastly, where is the best place to purchase Kerdi and any tips for its application?

Thanks again, I appreciate all the help.


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fixing a tile job nightmare

Bill, - all this came after a tile nightmare - see below - my thinking was to paint the redgard over the liner seams overlappying thickly so any water getting through the tile and grout would sheet to the liner and run to the drain. The previous shower didn't have any membrane at all - it was just mudded. And actually the "general contractor" I hired to do the job said he had done tons of tile jobs "travertine and marble etc. etc. in LA/San Diego area" (I should have called some of those references) - then halfway through the job he just didn't show up - when I finally reached him by using my cell phone that had a different area code (he never returned any of my or DH calls left on his cell and home phone) he said I could "hire someone else for the amount of money I owed him" - I told him I didn't own him any more money till the job was completed. (I had paid him half already and I bought all the materials) Supposedly he was getting a "6 figure job in Florida" and I was left with a real mess - even had to rip out some tiles around the caddy and window because he started his tile run at the edge of the shower and when the tile reached the window and caddy there would have been only a 3/4 inch of tile at the caddy and window - we have 12x12 tiles in there. We made the best of the situation by being creative and fixing a lot of his mistakes. I had actually gotten local references for other work he had done in this area - and he had done some stucco repair for us on another part of our house and had done fine. After he quit, I checked his contractor's license in the computer and his license was expired. As has been said by lots of folks here - now that I am looking back through other posts, just because someone is a general contractor - doesn't mean they can do tile in a correct or an esthetically pleasing way. I think our tile job will be ok - I feel the redgard and fibermesh overlapped at the seams will create an impervious membrane. But next time I will check the work every step of the way - DH had initially told me to "leave him alone - the job will turn out fine" - some of the things he was doing didn't seem quite right - he didn't know anything about the rubber liner ??? red flag - and wanted to use mastic - I told him not to and why - then he sneaked mastic in my house and used it on the floor tile - that didn't dry for 4 days. After he quit we pulled up all that tile (the mastic still hadn't dried) and cleaned it off and were able to reuse it. Now I know to trust my instincts and the valuable advice of you and others on this forum.


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RE: Question for Bill or other expert about Redguard waterproofin

This is quite new to me but if I understand you correctly I need to float a concrete floor sloped at 1/4" per foot for drainage, placing the Kerdi material directly on top of the newly floated concrete, followed by thin set, tile and grout? No other steps?

That's somwhat simplified, but nope-- that's it. :-) One thing you need to be aware of-- in order for this system to work, you NEED to use their drain. It has a halo around it that the membrane gets affixed to, thereby giving a complete seal to the drain.

springvalegardens-- I know this is all in retrospect, but this statement-- some of the things he was doing didn't seem quite right - he didn't know anything about the rubber liner ??? red flag wasn't a red flag. That by itself is enough to throw the guy off the job, lock stock and barrel, right then and there. Do not pass go, do not collect 200.00. That's enough to make it perfectly clear that he has absolutely no idea of what he's doing.


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RE: Question for Bill or other expert about Redguard waterproofin

Bill, you are correct - but I had already paid him half of the money up front - which he said was customary. He had asked for half of the money up front when doing the stucco job and he did complete that several months earlier to our satisfaction. After he started doing things in the shower I thought weren't quite right, I started checking on all of his work, looking in this forum, asking questions, etc. - to be sure he did it correctly. I knew that another tile contractor would not want to follow what he did - they would want to rip everything out and start from fresh because they wouldn't want their reputation based upon someone else's work - and we don't have an unlimited amount of money to pay twice - we are on a very tight budget. In fact I called several tile people and either they were too busy or they said they didn't want to finish a job that was already started. Looking back I see that he probably has done the same thing to a lot of people - gets some of the money up front and then only does a little work and then asks for more money, etc and then quits and the homeowner is left holding the bag. He actually asked me for $100 more and I said no I would not pay him any more money until the job was done - and that was when he didn't show up the next day or the next day, etc and we called and called. I think this is what is called a "con" - then they leave town and no one can find them. I will be making a complaint to the contractor's board and hopefully they can catch up with the guy - so other trusting and unsuspecting homeowners do not have the same "con" pulled on them.

I have heard that other supposed contractor's who have done this have been put in jail - and they should be. I live in a small town and I am telling everyone I know about this person - so if he ever comes back - people will know what he does.


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RE: Question for Bill or other expert about Redguard waterproofin

I am building a steam shower upstairs in my house. Right now this is the plan.
6mil sheat over 3/4 floor and up the walls about 6 inches. 1 1/2 to 2 inch sloped TYype S masin mix floor. Then 40 mil shower pan linerglues down and around the drain. Next another type S mix 1 to 1 1/2 inches over shower pan with wire mesh installed in it. Lastly tile set on thinset.
Does that sound good enough?

Second part for the walls I was using the 6mil sheet up and over lapping on teh walls followed by a Hardie board. Should I redguard the Hardie board (corners and walls)before I sert teh tile on teh walls?

Last part what about the bench area. Can I install shower pan liner then hardie baord and tile right over this or should I use Redguard on the seat as well?

Thanks for the time.


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RE: Question for Bill or other expert about Redguard waterproofin

Help!

I have a leak under our wood floors AGAIN! ...and have now replaced the wood floors twice. We're about to go for a third time!!! A leak detection company came in the first two times and said that the water is coming from outside the house so we installed a french drain the first time and remortared the chimney (the second time), which were the proposed solutions. I have had pressure tests each time and they come up clean, so now the thinking is that I have a ground water leak that is coming up through the slab. The latest recommendation is to raize the floor again, and use Red Guard as the membrane and then either put wood or tile down. Any suggestions?


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RE: Question for Bill or other expert about Redguard waterproofin

If you've got ground water coming through the slab, then you need some other solution than waterproofing the slab!! Believe me when I tell you-- water will not be stopped. You'll build up what's called hydrostatic pressure until the waterproofing membrane gives way, and then you'll be right back to square one. You need to get an engineer in there to figure out a way to redirect the flow of groundwater, if that's what it really is. if that IS the problem, I'd be curious as to what redirected the flow in the first place to start coming through your slab.


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RE: Question for Bill or other expert about Redguard waterproofin

OK _ here my situation _ I have gotten as many asnwswers as there are people. I have an 800 sg ft interior space joist 2 x 12 16 and 12 " oc. 3/4 advantec with radiant tubing on top./ I am going to pout a 3000 psi concrete and then finsih . OK so now onto isolaation membrae or crack isolation. WIll redguard serve as an appropriate crack isolation system? I know there is Ditra but at $2.75 a sq ft I might as well just put down a wood floor. OK let me drive ya nuts. Local tile guys here are telling me put down vinyl at 0.10 sq ft glue it to the concrete and you will have a very sturdy and very cheap crack isolation membrane

Mike


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RE: Question for Bill or other expert about Redguard waterproofin

If you shortcut now, you'll pay for it later. As for Ditra at 2.75 a foot, that's robbery. Go to tile-experts.com . I think you'll be very pleasantly surprised..... even AFTER shipping.


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RE: Question for Bill or other expert about Redguard waterproofin

We had a spillage from our bathroom on to our carpet, we took the carpet and underlay up and now just have bare concrete that kind of smells a little musty/moldy, if that is the right word. We have tried to make sure it is completely dry and now we have purchased Red guard sealer. Will this work to get rid and seal off future musty/moldy smells? What would you advise when using this product? We plan to put in a new wood floor once we have figured this out.


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RE: Question for Bill or other expert about Redguard waterproofin

coco-- you may want to wash that concrete down with bleach, first. The only thing that you'll accomplish with the Redgard is that moisture will not transmit thru it. If there's nold or mildew growing in or on the concrete, you want to kill it before covering it up.


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RE: Question for Bill or other expert about Redguard waterproofin

I was told by a licensed contractor (in CA) that redguard is the choice for waterproofing a fountain before applying tile. Would you agree? If not, what is the ideal choice to waterproof (and handle any small cracks that may occur in the concrete) a fountain??
Thanks! :)


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RE: Question for Bill or other expert about Redguard waterproofin

I would NOT agree. My choice would be one of two-- Either Laticrete's 9235 or Hydroment's Ultraset. This is contingient on the water fountain being in an area where freeze/ thaw issues aren't a problem. :-)


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RE: Question for Bill or other expert about Redguard waterproofin

Hello Bill or other expert,

I live up in rainy British Columbia in a rather unusual house build of stone masonry and concrete. There is a rooftop deck - which is made of a concrete slab, and about 4 years ago slate tile was installed on to this deck over top of redguard which had been trowel-ed on, supposedly according to the instructions (I was not present during any of this) Lost story short...the majority of the tiles have a hollow sound to them, and I've been able to lift a number of them by hand with very little effort...and it was wet under the tiles...At this point I'm looking for a permanent solution. I intend to remove all of the slate tile, and redo the whole deck - possibly using Ditra as the isolation/membrane this time around. But what I'm wondering about is - do I need to try to remove the redguard which is still (mostly) adhering to the slab? The original mortar didn't seem to bond to it at all.. Also, I'm hoping to increase the grade on the patio/roof in order to increase drainage...is there any way short of pouring another slab (which would need to be another 4 inches at the thinnest and therefore not an option) The deck/roof is basically 17' x 18'...would I be insane to try and make a mortar bed for that size?...would it be too prone to cracking or other problems?

Thanks for any insight you can give!


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RE: Question for Bill or other expert about Redguard waterproofin

One way or the other, the deck needs to be sloped a minimum of 1/4" per foot. It sounds like one of your problems is that water sat under the tile, but on top of the Redgard, froze, and popped the tiles loose. Although some will agree with using Ditra outside, I'm not a big advocate of it. Schluter even says it's okay-- so long as you use the Kerdi-band on the seams. My preference would be for another product put out by the Noble Company called Nobledeck. it's made SPECIFICALLY for exterior applications. it's a tough membrane that goes on basically the same way as Kerdi, and like Kerdi, tile can be set directly over it. Also like Kerdi, it only adds about 1/16" to the subfloor height.

Here is a link that might be useful: Nobledeck (3rd item down the page)


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RE: Question for Bill or other expert about Redguard waterproofin

Thank you Bill, In my web browsing I was starting to wonder if Noble was the better product for my situation. So, would the best way to go about this be: to remove the old redguard (in some areas it's removing itself anyway) and then use deckmud or concrete to get the slope, then use Noble deck under the tiles and thinset? Or would it be to strip the redguard, put a whole new layer of redguard down, then add the slope and put the noble deck etc down? Also, what is generally the best way to add a slope to an existing concrete slab over an occupied area that will result in the least additional height being added? ie how thin can either deck mud or concrete for this purpose be?

Thanks again, it's great to have access to some real experts online.


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RE: Question for Bill or other expert about Redguard waterproofin

remove the old redguard (in some areas it's removing itself anyway) and then use deckmud or concrete to get the slope, then use Noble deck under the tiles and thinset

hatsa the one. :-)


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RE: Question for Bill or other expert about Redguard waterproofin

I am currently taking quotes to tile my entire basement floor which is a concrete walkout basement. Approximately 650 sq. feet. This home was built in 1980 and although the floor does have minor cracks throughout it's area, these cracks are nothing major and have not appeared to change over time. I am finding that opinions vary by contractor. One says he recommends covering the whole floor with a thin rubberized membrane, while another claims that to be overkill and only recommends using Redguard on the more prevalent cracks only. As you can imagine, there's a substantial cost difference as well. My objective is to get it done right and to guarantee a longterm, crack free tile installation. Please advise me as I'm reading mixed reviews regarding Redguard and find it being used more for moisture barriers more so than for crack isolation. Any suggestions?


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RE: Question for Bill or other expert about Redguard waterproofin

Okay, let me put it this way. BOTH contractors are right.... SO LONG as none of the cracks have one side higher than the other. The Redgard should be enough, but no matter what product you discuss, the sheet membranes will outperform roll on or trowel on products every time.


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RE: Question for Bill or other expert about Redguard waterproofin

Good afternoon, I am not sure if you answered this previously as I tried to read through all of the posts. I am redoing my shower and just have a few questions. Currently done, I have a pre-sloping concrete slab with rubber membrane(up about 12 inches on the wall and over the curb) towards the clamping drain. I have the backerboard about 1.5 inches above the rubber membrane currently. I am soon about to poor the second cement layer which will also be slightly sloped and where the tile will be layed. 2 questions. First, I do not have a vapor barrier behind the CBU, I plan on using Redgard or blue seal, this should be applied to the entire cbu and especially in the corners and use fiberglass mesh, correct? Also, which is the main question, if I use either of these, I can use laticrete mega bond with latex adative (from lowes) to adhere the tiles to the wall (directly to the redgard or blue seal), correct? Thank you.


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RE: Question for Bill or other expert about Redguard waterproofin

First, I do not have a vapor barrier behind the CBU, I plan on using Redgard or blue seal, this should be applied to the entire cbu and especially in the corners and use fiberglass mesh, correct?

Correct. In the corners, also use thinset to fill any gaps before applying the membrane.

if I use either of these, I can use laticrete mega bond with latex adative (from lowes) to adhere the tiles to the wall (directly to the redgard or blue seal), correct?

Correct.

I LOVE it when posters can answer their own questions!! :-)


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RE: Question for Bill or other expert about Redguard waterproofin

Bill, thanks for the quick reply. In the shower, currently there is no vapor barrier as stated before, if I did have a vapor barrier, would I need the redgard? (I read a few places that both is bad as it could lock the moister between the two layers.) Also, if I just used the vapor barrier, is 15 lb roof paper sufficient? Thanks again.


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RE: Question for Bill or other expert about Redguard waterproofin

No, and yes. :-)

(no you wouldn't need the Redgard, and yes the 15 pound tar paper would be sufficient. Matter of fact, it's recommended.)


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Redguard waterproofing, Ditra or something else?

Hello, I am hoping for some help with a moisture problem in our home.

We live Central California, in a 20 yr old home with a slab foundation We have noticed dampness and now dark/mold spots on top of our carpet in some areas. We have checked the walls and pipes and there are no cracks or leaks.

We have been told that it is moisture coming up from the gound through the slab and that we need to pull up the carpet/lino and put in a moisture barrier THEN we can put in new carpet and tile/lino and won't have to worry about it any more. I was also told we could just put a barrier over the lino (without pulling it up)and that it would be ok to tile/lino over it.

I have searched online and found out about DITRA, and today I was told about Redguard by a Home Depot employee.

I am somewhat confused about which product would solve our problem. I read that membrane type barriers will
out-perform the trowel/roll on types, but was told that they really won't "solve the problem" and that they will just trap the moisture between the slab and membrane leading to mold/mildew problems. Is this right?

I really want to do this right so that we can do it once and be done with it.

Any insight would be MUCH appreciated!

Shary


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RE: Question for Bill or other expert about Redguard waterproofin

Moisture will not be trapped. It'll follow the path of least resistance, just like electricity, in this case, that being out to the edge of the slab. I understand the whole trapping issue-- it stands to reason that moisture would be a constant directly under the Ditra. However, if you trowel apply a membrane on, like Redgard or 9235, then the same argument could be used about moisture IN the slab. Mold could also start there, as well. But just like directly below the Ditra, it won't.


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RE: Question for Bill or other expert about Redguard waterproofin

I removed an old fiberglass tub and one piece surround and have installed a new tub. I hung green board above the new tub and want to install a tile surround. I was told by a friend to put tar paper over the green board and mud over that. After the mud dries I can put thinset and install my tile. However when I went to Home Depot to buy the stuff they recommended to install the tar paper on top of the green board, then 1/2" hardiboard, then thinset and tape hardiboard seems, then apply redgard over all of the hardiboard, then thinset, then tile. If I go the hardiboard route do I need the tar paper behind it or can I just use redgard on top? Or can I just put tar paper behind the Haridiboard, thinset and tape the seems, and then put the tile? What is best method (i really don't want to float all the walls with mud).


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RE: Question for Bill or other expert about Redguard waterproofin

Okay. This is the very first time I've ever heard of it being recommended to someone to DIY their own mudset walls! 90% of the tile PROS I know can't do that!! LMAO

A couple of comments concerning the Hardi. First, there's no need for the greenboard. Take that right down. ALl you need is 1/2" Hardiboard, and you're good to go. Secondly, either or, between the tar paper or the Redgard, BUT NOT BOTH. You can either staple tar paper up to the studs behind the Hardi, or you can put the Hardi up and paint it with Redgard. Either one will work just as well to meet requirements for a wet area. But doing both will create what's called a "moisture sandwich" where moisture can get trapped and cause a terrific breeding ground for mold and mildew to grow.


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RE: Question for Bill or other expert about Redguard waterproofin

My bathroom walls, including the shower area, are covered with Georgia-Pacific DensArmor Plus. I have a Kohler shower pan in place and I am planning on puting tile or travertine on the walls in the shower area. Which would be a good way to go; Redgard-thinset-tile, Zinsser Gardz-thinset-tile or Kerdi-thinset-tile? Or none of the above.


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RE: Question for Bill or other expert about Redguard waterproofin

The only one of the above I'd recommend would be Kerdi over the DAP, but I'd call Schluter tech or check out the Schluter website to see if it's a recommended substrate. I'd think it would be since Kerdi can go over regular drywall.

With DAP not being an approved tile backer in wet areas, I wouldn't recommend RedGuard over DAP.

I haven't used Kilz's product so I won't comment on that.

Mongo


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RE: Question for Bill or other expert about Redguard waterproofin

I'm finishing my basement and would like to tile the floor, walls & ceiling of the bathroom. The shower stall would have the same tile on the walls, but an acrylic base (pan) w/glass doors. Currently the room is bare studs on 16" centers, cement floor & roughed-in plumbing w/no floor drain. Since the room will be used by tenants, I'm trying to make it as bullet-proof as possible. How does this sound: Fire/Acoustic insulation in wall/ceiling, 6 mill poly on studs/joists, 1/4" hardi-board on walls (some kind of 1/2" board on ceiling), .... Then I'm not sure. Maybe a layer of RedGuard & then the Kerdi for walls & ceiling & Ditra for the floor?


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RE: Question for Bill or other expert about Redguard waterproofin

I guess you ARE trying to make it bulletproof! Problem is that the over kill will actually cause the shower to fail. In addition to the vapor barrier, you're also talking about using two different waterproofing systems, one over the other. One of the three (my choice would be Kerdi), and forget about the other two. Also, you CAN NOT use 1/4" cement board on walls. It must be 1/2".


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RE: Question for Bill or other expert about Redguard waterproofin

OK. So No Vapor barrier. 1/2" cement board on walls/ceiling (RedGuard seams/screws?) and then Kerdi on walls & Ditra on floor?
-Owen
p.s. thanks for that quick response! =)


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RE: Question for Bill or other expert about Redguard waterproofin

No Redgard AT ALL, if you're going to use the Kerdi.


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RE: Question for Bill or other expert about Redguard waterproofin

Thank you for the good advice. I will be tiling above a tub, and will be applying Redguard to the CBU. My only concern is closing the gap between the first row of tile and the tub. If the Redguard creates a membrane that is intended drain moisture, I assume I should not caulk the gap between the tub and first row of tile to allow water out? Or is this okay to caulk the gap because it acts like a masonry cavity wall system where any trapped moisture will be able to breath its way out of the tile and grout?


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RE: Question for Bill or other expert about Redguard waterproofin

Can Red Guard be used with radiant floor heating? Tubing inbeded in the concrete.


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RE: Question for Bill or other expert about Redguard waterproofin

Bill,
I started a foyer retile job on a house built in 1953. During demo I found the floor has about 1-1.25" mortar bed on top of 1X3s and 1X6s with gaps between some of those boards. The tiles are 1/2" thick and they chipped off but left a rough surface since they had lugs and the wide grout left little ridges. I'm left with an avg of 1/2" of elevation to get flush with the surrounding hardwood floor.
There are a few hairline cracks in the old mortar bed and I'm wondering if I can leave it and add something to minimize the cracking potential. The Tile shop guys said to put Redguard over the cracks and then a thick layer of thinset to raise the tiles flush with the surrounding wood floors. I thought Redguard was more for water proofing than for crack isolation.
I was thinking that I need to level the uneven surface of the mortar bed with either leveling compound or thinset and while I'm doing that, imbed a layer of Ditra (or similar) on it before it dries. Then thinset the new tiles on top to get them flush with the hardwood flooring. Doesn't the Ditra isolate the movement to greatly reduce the chance of cracking? Help!


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RE: Question for Bill or other expert about Redguard waterproofin

Hi Bill! Can I use Red Guard sealer on cement floor if I will install electrical heating under tile? Thank you, Nikoai


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RE: Question for Bill or other expert about Redguard waterproofin

Bill - need your .02 on my project.

I am building a patio kitchen and need some advice. The structure is constructed out of 3/4 plywood and 2x4s. I had planned on using Redgard around around the base and tar paper the rest of the before putting down the backerboard.

We will be tiling the bar & worksurface with a natural stone for the back and front.

I guess my real concern is the redgard. I would like to protect the base as much as possible.


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RE: Question for Bill or other expert about Redguard waterproofin

Ive put tar paper up on the studs and then cement board. Do I need to use redguard over top of the cement board and if I do can I use a premixed motar for tiles. I have caulked the tar paper to the shower surround and I have caulked under the cement board. When I install the tile should I grout or caulk under the tile.


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RE: Question for Bill or other expert about Redguard waterproofin

remodeling bathroom,if a tar paper was installed behind hardibacker is redguard needed before marble tile also using a premix high performance thin set(omni grip)I think my tile will bond better & omni grip has a mold type of control am i on the right track.signed mr inexperienced


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RE: Question for Bill or other expert about Redguard waterproofin

I'm attempting to tile my tub surround, and I've already got my cement board screwed in, mud and taped. I did not use a vapor barrier, but I purchased the Redguard. I also purchased a big tub of the premixed ceramic tile adhesive. Will the adhesive create a problem for me when I try to put that on top of the Redguard?


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RE: Question for Bill or other expert about Redguard waterproofin

I'm attempting to tile my tub surround, and I've already got my cement board screwed in, mud and taped. I did not use a vapor barrier, but I purchased the Redguard. I also purchased a big tub of the premixed ceramic tile adhesive. Will the adhesive create a problem for me when I try to put that on top of the Redguard?


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RE: Question for Bill or other expert about Redguard waterproofin

I am planning on using ditra on a floor tile project and I am doing hardibacker and redguard on the shower walls. Rather than buy another product (kerdi band) I was wondering if I could use the redgard to seal the ditra seems or if I have to buy the kerdi band?


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RE: Question for Bill or other expert about Redguard waterproofin

Bill.. I really need to know if Redgard will bond to linoleum flooring as I need to put a liner down and then pour a pan for a 10x12 area but can't use a sheet of lining because the liner has to go 2 ft. up a wall that is made out of big rock and morter. My question is can redgard bond to linoleum flooring and the rock wall? I want to put the redgard down and then pour a pan with quicklevel morter because there has to be a drain installed. then level the wall out with mortar and finally install ceramic tile over all of it. Is that going to work?


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RE: Question for Bill or other expert about Redguard waterproofin

I need some assistance! All the help I could get actually. My boss used redgard on the gybcrete cement and it's peeling off. Is this normal? He put a primer of water and redgard on the floors first (mopped before applying). Once the primer was dried we put the redgard on and left it for the weekend. Came back to the job site and the redgard was peeling up. We pulled it and it came off in sheets. Is this normal? Please help!!


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RE: Question for Bill or other expert about Redguard waterproofin

RedGard can only go over Gypcrete 2000.

Other than that, it sounds like things were done correctly. The primer should have been a 4:1 ratio of water:RedGard, each gallons of primer will cover about 250sqft of gypcrete.

Porous gypcrete may need two coats of primer.

Primer dries in about 45 min to an hour. The topcoat with RedGard.

If the Gypcrete was GC2000 and there was no flaw in your application methods, it'd make sense to call Custom or Maxxon tech support. I recommend taking some photos and having them handy to email the tech guy when you get on the phone with him.


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