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jacko93
11-27-2005, 02:00 PM
Everything I have read so far about Redgard tells me that it is a great product when used on shower or sauna floors, I have not read anything that indicates that it can (or cannot) be used on walls for as a water barrire before tiling walls. My question is - can I/should I put Regard on top of Hardibacker before I tile my tub/shower walls?

Thanks
Neil.

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Davestone
11-27-2005, 03:02 PM
You can, and some do, when doing saunas. Just use a modified thinset.

geniescience
11-27-2005, 06:10 PM
Six months ago I asked the same question, about any old liquid membrane that you can either roller on, paint on or trowel on. And nobody answered. ;) But later I read here in many posts about people doing it that way. Redgard, Mapei HPG, whatever. There are differences, and I don't know enough to describe them. I do 'know' from reading here that Redgard is prolly the best because people use it for steam shower wallls, and the Redgard manufacturer warrants it for (residential) steam shower walls too. Steam applications are the toughest in terms of vapor pressure. Hope this helps.

jacko93
11-27-2005, 06:11 PM
I will definitely use a modified thinset, however I get the impression from your reply that using the Redgard is an overkill and not necessary for the walls of a normal tub/shower combo.

Just to be real sure - I do not have a vapor barrier behind the Hardibacker board so thats why I thought I should play it safe and put the Redgard on the Hardibacker and then the tiles on top of the Redgard using the modified thinset.

I suppose my main concern is - Will the tiles stay attached to the Redgard (hardibacker, Redgard, modfied thinset and then tiles) even with a modified thinset?

If this is really an overkill or there is some doubt if the tiles will hold, I will return the Redgard and save the $.

Thanks for you help
Neil.

geniescience
11-27-2005, 06:14 PM
Matt,
The average expert here will tell it is not overkill. I'll stop posting now so's they can come in and confirm.

Theoderik
11-27-2005, 06:21 PM
Neil - look at my thread (do a search on "shawn's" and you'll come up with it.) I used RedGuard in my bath. I did the shower walls, the ceiling and the edge of the flooring. You can see pictures of it.

As a note - I DID have it on my CEILING and I tiled that as well. The tiles stuck with no problem at all. I think you'll be fine. And although the stuff is pricey - I do NOT think it is overkill. Money well spent for peace of mind.

Water leaking through walls is NOT a problem I want to deal with. Not in any shape or form!

sw (shawn)

oogabooga
11-28-2005, 04:01 AM
Neil,

Paint on acrylic waterproofing is pretty much the standard here in NZ and Australia. As long as you follow the manufacturers directions you shouldn't have a worry. The most common problem is that some tilers start putting tile up before the membrane is fully cured, or the membrane is put on far too thin (and therefore cannot accomodate movement). As others have said, use a modified thinset and you're good to go. BTW nothing wrong with overkill in a wet area.

Rob.

Davestone
11-28-2005, 04:12 AM
Like everyone says..that's fine,especially since you don't have the vapor barrier.We tend to answer things differently,for different questions...a lot of things to consider...some people have already spent a lot on materials,and such and i tend to not force them to spend more,and also when we're answering a lot, we tend to hurry and not give lengthy answers,and we have to take into consideration the perceived skill levels of some..not meaning you...but some diy will tend not to do a step right which will cause a failure, and we gear answers accordingly sometimes....then sometimes we miss you all together. :D

gof
11-28-2005, 02:57 PM
As a note - I DID have it on my CEILING and I tiled that as well. The tiles stuck with no problem at all.

Shawn, I'd say the picture in your thread might refute your "no problem at all" remark :stick:

:D

Theoderik
11-28-2005, 04:46 PM
Ouch, jerry - that hurt. :)

Actually, THAT was from a wall tile. ( I think my mortar was skimming over a bit. I should have back buttered the buggers).

Talk about a lesson HARD learned.

I'm hoping that wasn't an indication of the future and they are gonna start falling off the wall now. Only time (and headaches) will tell.

sw (shawn)

jacko93
11-30-2005, 07:26 PM
Appreciate everyone's input on this, I applied the Redgard today and will begin tiling very soon!

Thanks
Neil :wave: .

jacko93
12-04-2005, 02:25 PM
:scratch: A week ago I got a lot of useful tips (from this site) about using Redgard on top of Hardibacker. Now it's come time to tile and while l was laying out the reference lines etc I pulled off a piece of Blue tape attached to the bath and a splash of Redgard. I ended up easily pulling up a small peice of the Redgard attatched to the Hardibacker, I pulled a little more and now have a 9" tear in the Redgard!!!!

Now I am really worried if I can easily pull the Redgard away from the Hardibacker by hand I am sure my tiles will just fall off the wall (Modified thinset or not) .

Is this Redgard stuff any use at all, I want rip it all off an apply the tiles directly to the hardibacker any thoughts - HELP????

Thank
Neil.

pitterpat
12-04-2005, 02:31 PM
:scratch: Is this Redgard stuff any use at all, I want rip it all off an apply the tiles directly to the hardibacker any thoughts - HELP????

Thank
Neil.
Yeah it's useful but I've never put it over Hardiback...don't know how that effects it.

jacko93
12-04-2005, 02:38 PM
Here is a picture of the tear, I feel that I can easily continue this up the wall, any ideas??

Thanks
Neil.

chukar8
12-04-2005, 02:55 PM
did you wet the hardi before installing the redguard, or was the surface dusty????

one thing for sure i would by no means install anything till its corrected.

jacko93
12-04-2005, 02:59 PM
I did wet the walls as mentioned in the instructions, however the walls do feel a little dusty, now that I have removed the Redgard?!?

Neil.

Dog paws
12-04-2005, 03:00 PM
Hi Neil, don't go pulling it off just yet. I'd cut out the tear with a razor knife just slightly bigger than what it already is. Reapply RedGard in the void and overlap the existing about an inch.
And quit pulling on your membrane will ya :D
The pros will be along soon with more help. One of the moderators might ping our local Custom's rep.

chukar8
12-04-2005, 03:05 PM
before you go masking youre tear figure out whats wrong, so it can be corrected, youre tile will only be as good as its weakest link.

Viper
12-04-2005, 03:16 PM
That pic reminds me of the primer I used on my new drywall. Everyone told me to use Gripper by glidden(it's the best they said) and it peeled off exactly like your Redgard is doing.
Hope you can get a reply from a pro or even better the redgard rep. Good Luck

jacko93
12-04-2005, 04:23 PM
Well after all the sage advice the Redgard is a serious waste of time and money!!!

Hardibacker is naturally dusty and even if you wet it before applying (as per the instructions) the pesky stuff just peels off in huge sheets days later!!!! :crap:

I was unsure at the begining (hence the initial ?) and happened to peel a small piece accidentally while laying out the reference lines, ended up peeling off the lot.

My Advice DON'T use Redigrad on Hardibacker EVER!!!!! unless you like peeling things and wasting $40 and a couple of hours.

Neil.

gof
12-04-2005, 04:26 PM
I concur with Viper. I'd contact the manufacturer. This is a case where a blow up of that picture faxed (or emailed if you can find a contact email) to the manufacturer rep will give you the appropriate guidance as only they know how the material is supposed to behave. I'd worry about the membrane slowly pulling away and all your tile slowly heaving inward. Or worse, leaking!

But, be sure to CC us with their reply!!

jacko93
12-04-2005, 04:34 PM
Well I ended up peeling off the lot and it all came away way too easily, huge sheets of Redgard!!

My opinion - Hardibacker is naturally dusty and even if you do wet it (which I did), the Redgard will never stick to it strong enough to hold on to the tiles!!!

Big waste of time any money - If the Redgard rep does read this I want my $40 back!!!

Annoyed!!
Neil.

Rather-Be-Boating
12-04-2005, 04:34 PM
Given the number of messages I have read about RedGard, surely there have been others who have successfully used it over Hardibacker....:???? Is this an isolated instance, or have others experienced the same thing with Hardi?

I will be at this point in my own project soon, and had planned to use Hardi and RedGard, so would love to hear some input.

Theoderik
12-04-2005, 05:19 PM
I RedGuarded my bath (see pic below) and had no problems. My biggest worry was scraping "grooves" into the redguard with my trowel. But, I think all went well. Either way - it's been a week and the shower is still standing. (grin)

sw (shawn)

vanwassup
12-04-2005, 05:41 PM
I am using Hardibacker in my shower and was contemplating using RedGuard. Wondering if I should do this now that you've had this problem? Maybe I'll stick to Kerdi...

pitterpat
12-04-2005, 05:55 PM
I am using Hardibacker in my shower and was contemplating using RedGuard. Wondering if I should do this now that you've had this problem? Maybe I'll stick to Kerdi...

I think that you can do this waterproffing cleaner by using Kerdi by Schluter. If you have John's Kerdi book you can read up on that method.

I have used Redgard and have no problem with it. But I have never used it over Hardibacker. If Hardibacker has a dusty surface to it then that is probably affecting your adhesion.
I RedGuarded my bath (see pic below) and had no problems. My biggest worry was scraping "grooves" into the redguard with my trowel. But, I think all went well. Either way - it's been a week and the shower is still standing. (grin)

Did you use Hardibacker in your bath too?

chukar8
12-04-2005, 05:56 PM
I RedGuarded my bath (see pic below) and had no problems.

you used durock not hardibacker.:)

jacko93
12-04-2005, 06:07 PM
From the photo's posted I see :shades: that Theoderik used DUROCK and not Hardibacker, maybe that why his tiles are still on the wall.

I have e-mailed the Redgard people, lets see what they have to say for themselves, until then my advice is Redgard and Hardibacker do not mix :bang: !!!

Neil.

muskymike
12-04-2005, 06:10 PM
Hi Neil, I never use hardi so I'm not sure. It shouda stuck to it though if it was washed down good.

jacko93
12-04-2005, 06:14 PM
PitterPat,

It's a tub shower combo,so I just used the Hardibacker on the 3 walls around the bath and was looking for some extra water protection. I decided on Redgard (after HD recommeded it + this site), however I believe that all have used it on Durock and not Hardibacker.

At this point I am thinking that tiles directly on the Hardibacker are the way to go! Anyone is this such a bad thing???

Thanks
Neil.

muskymike
12-04-2005, 06:18 PM
If you have a vapor barrier behind the hardi then you can, if you don't you'll have problems in the future.

Theoderik
12-04-2005, 06:31 PM
guess i wasn't any help. sorry. (grin).

all I know as a dumb DIY'er is I used "cement board". It was heavy, bulky, fairly price, a pain in the *** but, the job got done! WOOT!

sw (shawn)

chukar8
12-04-2005, 07:24 PM
all I know as a dumb DIY'er is I used "cement board". It was heavy, bulky, fairly price, a pain in the *** but, the job got done! WOOT!

hey, thats all i use on walls is durock or wonderboard, though im thinking of trying wedi. :tup2:

Rather-Be-Boating
12-04-2005, 08:31 PM
I am certainly no expert, but looking at both Hardi & the others, such as Wonder, Durock, etc, I don't see anything on the surface that should make a difference. However, since I have not yet installed my CBU, and was planning to use Hardibacker, I'm really watching this closely.

I think the specs for RG call for either a damp surface, or a recently sponged surface, don't they? Still - a slight deviation from that spec should not, IMHO, have such a dramatic impact as shown in this photo.

Hope JB, or others with "connections" will get us some intelligent input from Custom regarding RG & Hardibacker.

Rob Z
12-04-2005, 08:40 PM
Jacko

I don't think your "upsettedness" (invented a word :suspect: ) should be directed towards Custom's Red Gard. It sticks really well to cementitious surfaces, especially when they are free of dust. Hardi on the other hand could be the cause of the problem. It is extremely thirsty and it sucks the moisture out of everything.

I think if you skim some thinset over the Hardi, let it dry, and then reapplied Custom RG... you would see different results.

Scooter
12-04-2005, 08:56 PM
This isn't much help, but I'll toss my two cents in. I don't use RedGuard, which I consider to be very light duty. Instead I recommend Laticrete 9235. It sticks like glue.

e3
12-04-2005, 09:08 PM
did Custom say to wet the board?? i think it needs to go on a DRY surface...
after you wiped the dust off did you try to roll the redguard on to the board while it was still wet??? hmmmm

MD TILE INSTALLATIONS
12-04-2005, 09:15 PM
REPAIR THE MISSSING AREA AND INSTALL YOUR TILE WITH CONFIDENCE! I know it seems scary but it is also an anti-fracture membrane and is designed to move. make sure youve covered all areas to create a waterproof surface and allow repairs to dry before setting tiles. In order to remove dust wipe the area with moistened sponge. you may dilute first coat of redgard to act as primer coat then apply additional coats at full strength until youve reached your desired thickness, allowing for proper drying between coats.

Andrew21
12-04-2005, 09:30 PM
wow, thats really scary. Although I'm going to use Durarock, I'm gonna follow this thread closely also. I didn't know you had to slightly dampen the CBU before applying the RedGuard. Then again, I didn't read the directions on the bucket yet. :)

Viper
12-04-2005, 10:33 PM
I used Redgard on my shower with no problems, but I also applied it over Durock not Hardi

chukar8
12-04-2005, 10:51 PM
REPAIR THE MISSSING AREA AND INSTALL YOUR TILE WITH CONFIDENCE!

Im sorry but that is not good advice! if its peeling like you say it is that is too weak of a bond for a vertical installation!

Blackberry
12-04-2005, 10:57 PM
I may be wrong but I don't think it's the contact on a small area that matters but the whole or total coverage in addition to thinset and tile that makes it strong enough. You can peal Kerdi like that if you want. For that matter you can peal the paper off drywall too.

chukar8
12-04-2005, 11:01 PM
Ive never used it over hardi, but it bonded great to wonderboard, and durock.

im curious what the reps will say???

Kx250
12-05-2005, 01:52 AM
Good to know, We use red-Guard a lot, but never have used it with Hardi.
But we have a customer coming up the is requesting hardi for his shower.
I hate when someone gives them preconceived idea's about other backer boards but oh well, guess we will have watch how we do the shower with Hardi. I think this will be the first walls we have done with hardi, any other info on shower walls and hardi?

Steven Hauser
12-05-2005, 02:56 AM
Hi Neil and all,

The use of surface applied water and vaporproof membranes can be a good thing. :cool:

Like with anything else, the application process is quite important. :yeah:

All dust from the backerboard installation would need to be removed before the installtion of anything else. :nod:

In a sense you used your redguard to do that, it adhered to the dust. :twitch:

The other thing to remember is this, to get the Redguard to be a water and vapor membrane it must be around 45-46 mil thick dry.

This would require two applications each around 50 mil wet. If you apply the first layer up in an up and down motion, apply he second in a left to right motion.

Finally, it must be well adhered, if not you need to start over.

Hope this helped. :goodluck:

muskymike
12-05-2005, 08:13 AM
Hi Neil, I merged your threads together. We like to keep all the questions for the same project on one.

Rather-Be-Boating
12-05-2005, 09:59 AM
did Custom say to wet the board?? i think it needs to go on a DRY surface...
after you wiped the dust off did you try to roll the redguard on to the board while it was still wet??? hmmmm

From the RedGard Data Sheet (http://www.custombuildingproducts.com/docs/data_sheets/RedGard%20DS%203-05.pdf?user=diy&lang=en) :

"Dampen all porous surfaces. Use a 3/4" (19 mm) rough textured synthetic roller, or a 3/16" x 1/4" (5 x 6 mm) V-notch trowel. Heavily pre-coat corners and where floors and walls meet extending it 6" (15 cm) on either side. For exterior change of plane embed 6" (15 cm) wide fiberglass mesh into the membrane in corners and where floors and walls meet."

I'm curious about the mesh tape.... presumably, you would have used mesh tape and thinset at the corners (such as the inside, and outside corners of a nitch), correct? Is this layer of mesh sufficient, or should you add another layer of mesh when using the RedGard? Or, do you skip the tape and thinset and embed the mesh when applying the RedGard??

Viper
12-05-2005, 10:28 AM
Good question. I don't know the answer but when I did mine....I taped and mudded(with thinset) the seams in the Durock first, then a couple days later applied the Redgard.

nonstopaz
12-05-2005, 11:06 AM
I just removed a piece of hardibacker on my new tub surround I had not yet tiled to install fixtures. I redguarded it a week ago. The redguard peeled off in one piece. I swept the surface, cleaned it with a sponge, and waited for it to dry, then brushed it again before applying the redguard. I'm not worried about the tile falling off. I'm glad to see the redguard peel off in a sheet- tells me it'll do what I need it to do, waterproof.

cej22
12-05-2005, 12:01 PM
I just wanted to note that I used Redgard over Harbibacker making sure to dampen with a sponge before I rolled on two coats. I had no issues whatsoever.

jacko93
12-05-2005, 12:26 PM
Ok I know I was dissapointed (to say the least) with my peeling Redgard experience yesterday. :crap: Having read all of these entries I am willing to give it one more try.

As I believe this to be essentially a lack of adhesion due to dust I now have the cleanest and most dustfree Hardibacker on the planet. To achive this simply apply and easily remove a $30 Redgard face mask to my wall, removing the worst of the dust, wash it several times with clean water, followed by a final cleaning with a dry towel. :tup2:

I will damp down the Hardibacker and reapply the Redgard as per the instructions!

Thanks to all
Neil.

Viper
12-05-2005, 01:24 PM
No way after seeing those pics and others responses, would I use Redgard over Hardi. Why not use Laticrete 9235 and not worry about it this time.

Bruce K
12-05-2005, 04:53 PM
I did wet the walls as mentioned in the instructions, however the walls do feel a little dusty, now that I have removed the Redgard?!?

Neil.


Manufacturer surface prep states: "All surfaces must be structurally sound, clean, dry and free from contaminants that would prevent a good bond."

Were you reading RedGard instructions? I have just rolled 2 coats of RedGard, and all this "wet surface" prep has me scared. I just swept the cbu and floor dry, and rolled RG on, and it appears to be holding just fine...

tileguynky
12-05-2005, 05:10 PM
First off, I use Red Gard to waterproof all showers that I do. Second, I do not use Hardi. I use one of the following Durock, Wonderboard and Dalbacker (made by Permabase for Daltile).

Bruce K, click on the link of RedGard Data sheet. It is a PDF download.

Rather-B-Boating, this is a strange spot on their data sheet. They make this request but do not manufacture nor sell this product (Custom Building Products). However, TEC sells a 6" wide fiberglass mesh tape for their waterproof system. I use this tape at all joints. It is a much finer mesh than the tape that is being used when tape wonderboard with thinset. It cost about $6 a roll. I buy this stuff by the case.

As far as RedGard sticking, if applied correctly it does. I had to replace a tile that broke when the glass door guy tried to drill through it. As I started to chip the tile out it pulled wonderboard off the wall. Meaning the tile was well bonded to the RedGard by the thinset and the RedGard was bonded to the Wonderboard well enough that I had to patch the CBU, rewaterproof before installing the new tile.

Rather-Be-Boating
12-05-2005, 10:25 PM
Rather-B-Boating, this is a strange spot on their data sheet. They make this request but do not manufacture nor sell this product (Custom Building Products). However, TEC sells a 6" wide fiberglass mesh tape for their waterproof system. I use this tape at all joints. It is a much finer mesh than the tape that is being used when tape wonderboard with thinset. It cost about $6 a roll. I buy this stuff by the case.
Hmmm... so they are not talking about the same tape used for the seams? OK, I'm confused..... :confused:

So, there is supposed to be yet a different mesh tape in there? Again, is this in lieu of the tape & thinset, or in addition to it?

This whole RedGard/Hardibacker thing is a mess. I was hoping JB or one of the moderators with a toe in the door at Custom would provide some kind of clarification to this whole issue.

My shower project will limit any need for a membrane to just a nitche. Buying a $130, 2 gallon, bucket of Laticrete is not appealing to my budget!

jacko93
12-06-2005, 11:54 AM
Below is the answer (Hopefully :tup1: ) to the issue from the Custom BP support, looks like some of the suggestions in this thread were close, but here is the official solution.

Will post an update in a couple of days after trying this!
Neil.

Subject: RE: Feedback: Installation information - nwyates@yahoo.com
Date: Tue, 6 Dec 2005 10:20:31 -0800
From: "Technical Contact (Corp)" <technicalcontact@cbpmail.net> Add to Address Book Add Mobile Alert
To: nwyates@yahoo.com

Neil, Hardi-Backer (HB) is very absorptive board.

To get a good bond to HB with RedGard (RG) you need to make a primer coat of RG.

Primer is: 4 parts water, 1 part RG. Wipe down the HB with a wet sponge to get all the dust off the HB. Then apply the primer coat.

Let that dry for 3 hours then apply an undiluted coat of RG.



You might want to try this whole process in a small area to assure that is going to bond well before proceeding with this whole installation.

Rather-Be-Boating
12-06-2005, 01:16 PM
Looks like "MD Tile Installations" wins the award! Providing the proper proportions for the primer is a nice addition.

I would still appreciate some clarification on the mesh tape if anyone has an answer....

Viper
12-06-2005, 01:57 PM
Neil, Hardi-Backer (HB) is very absorptive board.

To get a good bond to HB with RedGard (RG) you need to make a primer coat of RG.

Primer is: 4 parts water, 1 part RG. Wipe down the HB with a wet sponge to get all the dust off the HB. Then apply the primer coat.

Let that dry for 3 hours then apply an undiluted coat of RG.



You might want to try this whole process in a small area to assure that is going to bond well before proceeding with this whole installation.

By the manufacturer telling you to try this on a small area first and see if it bonds, that tells me they are not totally confident it will. I wouldn't even risk it if I already had Hardi on the walls. I would use a different product. JMO Good Luck

gof
12-06-2005, 02:03 PM
By the manufacturer telling you to try this on a small area first and see if it bonds, that tells me they are not totally confident it will. I wouldn't even risk it if I already had Hardi on the walls. I would use a different product. JMO Good Luck
Nah, just means that there are enough lawyers and unreasonable people in the world that everything comes with a disclaimer these days :complain:

jacko93
12-06-2005, 02:07 PM
I must admit I am impressed with the responsivness from Custom BP + they have offered me a full refund on the can of Redgard that peeled away from my Hardibacker - can't beat that :nod: !!!

Neil.

Rather-Be-Boating
12-06-2005, 02:21 PM
.... especially if you have enough remaining to complete the job! :tup2:

tileguynky
12-06-2005, 03:50 PM
So, there is supposed to be yet a different mesh tape in there? Again, is this in lieu of the tape & thinset, or in addition to it?


Hmm, that is a good question. I use the mesh and redgard in lieu of the thinset and tape. I would not see much need for this mesh tape if the joints have already been filled in by regular tape and thinset.

Here is a pic of the mesh that I am using from TEC.
http://homepage.mac.com/ghiens/mesh.jpg

hth

Rather-Be-Boating
12-06-2005, 05:49 PM
Looks like a sizeable roll of that stuff. The only place I might use that is in a 16 x 24" nitch. Anybody sell that stuff in small quantities? I would only need about 15-16 Lin Ft. of it. Probably best for me to just proceed with the tape & thinset followed by RedGard.

tileguynky
12-06-2005, 06:23 PM
One roll is 50 lineal feet. YOu would be suprised how many of those rolls a person could go through in a simple 4x4 shower with a seat and niche.

pitterpat
12-06-2005, 07:04 PM
One roll is 50 lineal feet. YOu would be suprised how many of those rolls a person could go through in a simple 4x4 shower with a seat and niche.

Greg, so this stuff works like Kerdi-Band? And it seems like you use it instead of the regular "mesh"? It looks like it is thinner so you don't have that little bump, well not as much of a bump. And your broad knife goes over it real easy.

How much does it cost? Where is it sold?
Tks,

T_Hulse
12-08-2005, 01:32 AM
Sorry guys I didn't see this thread earlier. I use quite a bit of Redgard on many different kinds of substrates, including Hardi. I think the real problem here is that we think we have a problem at all. The Redgard in the picture above is not "peeling", it is "being peeled". That's a condition that cannot be duplicated under any circumstances after the tile is installed.
Redgard is not made as runny, watery paint type product that's made to absorb into the board like Latticrete 9235. It's completely different. It's made to dry just like a sheet membrane, sitting up on top. Compare it to Kerdi or Nobleseal. Any sheet membrane, if you start peeling with your fingernail under a corner, is going to pull away from the wall. Redgard is no different. Quit picking at it. ;)
It is not just waterproofing, but mainly a crack isolation membrane. It separates your tile away from possible cracks in the substrate. It needs to be able to stretch & move independently of the board & the crack, so that crack doesn't transfer through to your tile.
When dealing with isolation membranes, a stronger bond is not better. A stronger bond only does a better job of transferring unwanted cracks through to the tile. Instead, the best option is an adequate bond with a highly flexible membrane layer. Redgard has these.

tileguynky
12-08-2005, 05:52 AM
And your broad knife goes over it real easy.,

Not quite sure what you mean by board knife. (Sure it is a term I just have not associated with something.)

I buy the rolls from a TEC dealer here in town. My cost is right at $5 a roll. The actual store is Louisville Tile. My application is to use a paint brush, coat the seem and use my finger (wearing rubber gloves) to line the mesh up and push each end into the Redgard. Then using my brush, I start in the middle and work towards each end removing air bubbles, and embedding the mesh into the readgard. Usually by the time I am finishedapplying the mesh, the first part is dry enough to start applying the first coat of redgard on the entire wall.

T_Hulse, do you have either a Custom part number or a Daltile part number for the mesh. The local Daltile was unable to locate anything. Would much rather use the product designed to be used with it instead of a substitution.

Viper
12-08-2005, 06:27 AM
Sorry guys I didn't see this thread earlier. I use quite a bit of Redgard on many different kinds of substrates, including Hardi. I think the real problem here is that we think we have a problem at all. The Redgard in the picture above is not "peeling", it is "being peeled". That's a condition that cannot be duplicated under any circumstances after the tile is installed.
Redgard is not made as runny, watery paint type product that's made to absorb into the board like Latticrete 9235. It's completely different. It's made to dry just like a sheet membrane, sitting up on top. Compare it to Kerdi or Nobleseal. Any sheet membrane, if you start peeling with your fingernail under a corner, is going to pull away from the wall. Redgard is no different. Quit picking at it. ;)
It is not just waterproofing, but mainly a crack isolation membrane. It separates your tile away from possible cracks in the substrate. It needs to be able to stretch & move independently of the board & the crack, so that crack doesn't transfer through to your tile.
When dealing with isolation membranes, a stronger bond is not better. A stronger bond only does a better job of transferring unwanted cracks through to the tile. Instead, the best option is an adequate bond with a highly flexible membrane layer. Redgard has these.

Everything you say makes sense, but why did the manufacturer give instructions on diluting it and appling a primer coat first? Looks like they want it to stick better?


To get a good bond to HB with RedGard (RG) you need to make a primer coat of RG.

Primer is: 4 parts water, 1 part RG. Wipe down the HB with a wet sponge to get all the dust off the HB. Then apply the primer coat.

Let that dry for 3 hours then apply an undiluted coat of RG.



You might want to try this whole process in a small area to assure that is going to bond well before proceeding with this whole installation.

MikeS
12-08-2005, 06:56 AM
I had installed Hardi with the intention of covering it with Redgard when I saw this thread. I put some Redgard on a scrap piece of Hardi and the next day it peeled off pretty easily. I then followed the manufacturer's suggestion and primed another test piece with a primer made with 4 parts water & 1 part Redgard. The regular coat of Redgard stuck to this great so I feel confident using it now. Hope this helps any fence sitters.

Mike S

gof
12-08-2005, 10:05 AM
Mike,

Did you take any pictures of the peelable vs. non-peelable? How would you qualify the sticking better part?

MikeS
12-08-2005, 12:28 PM
Jerry

Sorry, I didn't take any pictures since I used a scrap piece of Hardi. However, there was a big difference between the unprimed adhesion and the primed. While the unprimed looked ok and seemed tight to the Hardi, once I scraped under it with a putty knife it came off in big pieces with no residue on the Hardi. With the primed, I tried to scrape it off with a screwdriver and only little pieces would come off but there is a residue of Redgard on the Hardi. I intend to go ahead and use the Redgard. When I get home from work, I'll see if I can post a picture of the primed piece.

Mike

gof
12-08-2005, 01:18 PM
Actually I think your written description hits it dead on. First attempt it peeled off indicating poor adheasion. Second attempt with the dilluted "primer" resulted in something that doesn't peel off. It seems like it may abrade off (i.e., scratch it and the scratches come off, but the material between remains), but even thinset might be considered to fall into that category :)

Boston Guy
12-08-2005, 03:29 PM
I'm about a week from redguarding over durock. So this thread first worried me then I guess there is no problem after all, and I'm not even using hardiboard. But where the planes change should I caulk that and then put redguard over it? And if it is caulked will redguard adhere to it? Or does the use of redguard mean that caulking in the corners (plane change) isn't needed.

I know that I'm probably worrying too much but when you only do a shower every 15 years or so, you want it done right. :tup1:

Thanks,

Don

T_Hulse
12-08-2005, 07:50 PM
Don the caulk won't help you under the Redgard, it's only for on top the tile. For inside corner plane changes we use 4" fiberglass mesh tape (alkali resistant), coated thinly with thinset, then Redgard on top. Occasionally we use the polyester fabric like in the picture below.

Greg H, sorry I don't have a part number for that mesh. I'm not sure they make it themselves. I think they're just referring to a generic brand.

Viper & Mike S, can either of you help me find the link to that recommendation regarding the diluted primer? I was aware they allowed it for gypcrete on floors but I didn't know they required it for Hardi on walls.

Viper
12-08-2005, 09:23 PM
Viper & Mike S, can either of you help me find the link to that recommendation regarding the diluted primer? I was aware they allowed it for gypcrete on floors but I didn't know they required it for Hardi on walls.

Earlier in this thread that was posted by the person having this problem. A direct quote from the redgard rep to him via e-mail.

Here it is:
Subject: RE: Feedback: Installation information - nwyates@yahoo.com
Date: Tue, 6 Dec 2005 10:20:31 -0800
From: "Technical Contact (Corp)" <technicalcontact@cbpmail.net> Add to Address Book Add Mobile Alert
To: nwyates@yahoo.com

Neil, Hardi-Backer (HB) is very absorptive board.

To get a good bond to HB with RedGard (RG) you need to make a primer coat of RG.

Primer is: 4 parts water, 1 part RG. Wipe down the HB with a wet sponge to get all the dust off the HB. Then apply the primer coat.

Let that dry for 3 hours then apply an undiluted coat of RG.



You might want to try this whole process in a small area to assure that is going to bond well before proceeding with this whole installation.

mark11755
12-08-2005, 09:53 PM
CBP does distribute their own mesh tape Try here:
http://custombuildingproducts.com/ProductCatalog/SurfacePrep/WaterproofingAntiFractureMembranes/Mesh.aspx?user=pro&lang=en

Ask your local distributor to procure.

Dinahpinah
12-11-2005, 05:35 PM
Well, there seems to be a conflict here. Tom Hulse says the following (see above in this thread):

"It is not just waterproofing, but mainly a crack isolation membrane. It separates your tile away from possible cracks in the substrate. It needs to be able to stretch & move independently of the board & the crack, so that crack doesn't transfer through to your tile.
When dealing with isolation membranes, a stronger bond is not better."

That makes sense to me, but it seems like some people are still aiming for a very tight bond between Hardi and Redgard. I could use a consensus since I'm planning to waterproof the bottom 10-12" of the Hardi going on my shower walls to prevent wicking.

cx
12-11-2005, 06:16 PM
The flexing of the membranes for purpose of crack isolation doesn't (shouldn't) involve the bond between the membrane and the substrate. The membrane is s'posta provide the flexibility between it's two surfaces.

We ain't talking movement like when you har a moving company here, we're talking bout thousandths of an inch most of the time. You want the membrane well attached to the wall; the primer makes a lot of sense.

My opinion; worth price charged.

T_Hulse
12-11-2005, 08:03 PM
I really don't think it matters either way. If the primer was a requirement from Custom, they would put it in print. It is however a convenient way for tech reps to address unfounded concerns over it's adhesion. It only needs to get about 50 psi of sheer strength to work effectively, and that's very low. With the primer it will far exceed that but still work great just in the body of the finished liner (if you get it thick enough; not many people do). It's unique in that it really does form a real "sheet" liner when applied properly. You can take a tiny piece & stretch it 1/2" or more with your hands... works great. :nod:

One other note, when you're waterproofing on the surface, you want to get up above the shower head all the way around. With only the bottom 10-12" done, water coming down behind the tile (the grout's not waterproof, you'll plenty of water directly through the wall tile grout) will get the board wet from above & down behind your waterproofing, trapping moisture behind it. Not a good situation.

Hickory
12-11-2005, 10:07 PM
Someone who seemed knowledgeable told me that my plan for my shower walls (to put up 6 mil plastic, covered by Hardibacker, covered by Kerdi) was double overkill that could backfire. He told me that the Hardibacker by itself was waterproof, and that you want one side of the waterproof membrane to be able to "breathe," to avoid trapping moisture between layers of waterproofing. (He advised me to use Kraft paper instead of the 6 mil plastic, over the studs. He also thought Kerdi was over-priced and over-rated.)

I'm detecting a distinct anti-Hardibacker group here. And I also have read here of projects using multiple layers of waterproofing.

Is my "expert" right about avoiding too muchwaterproofing (plastic/Hardi/Kerdi or Redguard)? And, straight out: what do you regard as the best underlayment for shower walls (most waterproof, best able to co-exist with RG/Kerdi/whatever), the most fool-proof, track-tested, and worry-free?

As for my expert's skepticism about Schlüter: One of the attractions of Schlüter for me is that for a novice, it presents a complete "package" for the drain, shower pan, and shower walls. And of course, John B's e-book is very helpful. Is there any similarly useful reference available for other products such as Noble's Chloraloy?

-- Hickory

alygal
12-11-2005, 10:20 PM
Adding my late 2c worth here.

We used Hardibacker with RedGuard for tub/shower surround and experienced no problems at all. We did not use any blue tape for layout lines (which seems to have initiated the situation for Jacko). We drew on layout lines to begin with and then just went from there.

cx
12-11-2005, 10:22 PM
Is my "expert" right about avoiding plastic/Hardi/Kerdi (or Redguard)? Your expert is correct that you do not want a moisture barrier behind the CBU and another on the front. Any moisture barriers, and any CBU. We lovingly refer to that as a moisture sandwich, and they are a bad thing.He told me that the Hardibacker by itself was waterproof,He is most incorrect about that. Hardiboard is not waterproof. It is impervious to water damage, but not waterproof. When used as a CBU in shower construction, it requires either a moisture barrier behind it, or a waterproofing membrane on the tiling surface, just like all other CBUs. I'm detecting a distinct anti-Hardibacker group here. And I also have read here of projects using multiple layers of waterproofing.
Don't know of any anti-Hardi groups hereabouts, Hick, just got people with various preferences for various kinds of CBU. Hardi has advantages and disadvantage, just like the rest. We do have a very small but vocal group who are against multiple waterproofing layers for the most part, though. :)

My opinion; worth price charged.

T_Hulse
12-12-2005, 09:13 AM
I agree with everything CX said. A moisture sandwich is bad & Hardi is good if used properly. Some quick pros/cons of Hardi for you: Hardi cuts easier & more cleanly than cement boards (you can use shears), easier to nail near the edges without blowouts, and transfers less water through it's core than cement boards. On the cons, it is a little harder to bond to, both waterproofing like up above & thinset. As long as you're installing things properly the bonding is fully adequate though. what do you regard as the best underlayment for shower wallsKerdi over anything (including sheetrock). :)

Hickory
12-12-2005, 08:10 PM
Given your recommendation, I think I'll use "green" wallboard for the shower area, covered by Kerdi. (Anything wrong with the "green" wallboard?) I'll use my stack of Hardi boards for floors and other walls.

Hardi is good if used properly. ... On the cons, it is a little harder to bond to, both waterproofing like up above & thinset.

Please check to see if I have this right from reading the thread: To make Hardi bond better (to thinset), clean it thoroughly with a wet rag... then do you let the Hardi dry out thoroughly or apply the thinset to a slightly dampened Hardi?

-- Hick

jadnashua
12-12-2005, 08:26 PM
Regular drywall is stronger and is all that is required. Plus, that is what Schluter specifies. Note (and I didn't know this myself until recently), drywall is stronger in one direction vs the other...ideally, you install it across the studs (horizontally), not vertically. Installed properly, Kerdi is waterproof - it makes no difference what is behind it.

Rather-Be-Boating
12-12-2005, 09:11 PM
Note (and I didn't know this myself until recently), drywall is stronger in one direction vs the other...ideally, you install it across the studs (horizontally), not vertically.

Where did you learn this? Never heard it before. I can think of various advantages to laying it horizontally, but none of them have to do with "strength".

T_Hulse
12-13-2005, 10:24 AM
Hick, apply the thinset while the Hardi is still damp.

Don, I learned it here on JB myself. Here is a link (http://www.tileyourworld.com/articles/USG-SheetrockPDF.pdf) from USG explaining it.

Rather-Be-Boating
12-13-2005, 11:56 AM
Interesting. Thanks for the link.

RandyW
07-14-2013, 10:13 AM
I came back to re-read this thread just before starting to Redgard my new shower. I am a diy so I wanted to be sure I did not f anything up, and I intend this installation to last for the life of the house.
The interior of the shower is Durock CBU but I also used some Hardi board around the door because it was easier to cut into thin strips. (used a wet saw, per advice learned elsewhere on this forum. Works great!)

I diluted some Redgard per instructions in this thread: 4 parts water, 1 part RG. It was basically cloudy looking water at that ratio. I rolled some on the HB and it soaked in immediately and dried within 15 minutes. But the coverage was barely noticeable. Most spots looked like original naked HB. So then I mixed another bucket, 1 part water, 1 part RG. This mixture was thinner viscosity than cheap latex paint, but it did cover better. As it rolled on, the pink was thick enough to cover the ink printing (I primed the Durock too, just as a precaution.) It soaked in well. I could tell that the HB was getting wet, even with the 4:1 diluted primer already on it. It all dried fairly quick (about 30 minutes) to the blood red color. The ink printing was still very visible. photo attached. There was no build-up of film thickness that could be peeled or scraped off.

I do understand that professional tilers don't want to spend time putting on multiple coats and waiting for it to completely dry between coats. So their method is to apply just one coat thick enough to meet the spec. Time=$, I respect that. But my diy time is virtually free.

Another "tip" I would like to include here: The CBU and HB collected a lot of dust from the drywall compound sanding done for the rest of the bathroom. Before priming, I vacuumed it off with the brush attachment, then wiped it with a wet rag. I rinsed out the rag frequently in a bucket of water, but soon that water was so dirty that I figured I was only just smearing the dust around instead of getting it off. So I brought in the garden hose and set the nozzle for a broad soft spray. All the gunk washed down the drain, and then I gave a good hard blast of full volume water pointed down the drain to flush out the trap.