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....use the 4-mil plastic behind the cement backer? I’m used to doing it with the plastic behind the backer, but I’m wondering if using the RedGuard would be better. I know you have to use a certain thin set with it, but I’m trying to understand how the tile actually bonds reliably to the RedGuard and is it really that much better than the “old” way.
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(07-30-2020, 03:16 AM)EightFingers Wrote: ....use the 4-mil plastic behind the cement backer? I’m used to doing it with the plastic behind the backer, but I’m wondering if using the RedGuard would be better. I know you have to use a certain thin set with it, but I’m trying to understand how the tile actually bonds reliably to the RedGuard and is it really that much better than the “old” way.
I used RedGard after watching some YouTube videos. The cardboard box water test sold me. Redgard puts the barrier in
front of the backer, and I can't see a downside to that.
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I used 6 mill behind the backer, but I have not yet applied the tile. I will use redgard over the cement board.
I think 6 mill is easier to handle and cost less than $20.00 for more than I needed.
I kind of which I had used the light weight Schluter board. The cement board was a bear to carry and a chore to cut.
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I skipped the plastic backer and I am glad I did. My reasoning: backer board is water resistant, but not water proof. That means that any water that gets through the tile grout will soak into the backerboard and eventually find its way through the backerboard. With 6 mil poly you have created the perfect terrarium. Better approach: stop the water from penetrating the backerboard in the first place. Enter: redguard. I used some stuff sold at my local tile shop that was a nice light green color. No issues with the tile adhering and not water leakage issues.My advice: skip the poly and use some sort of redguard type waterproof coating. Follow the directions in terms of how many coats, etc. It goes on very easy.
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Read the warranty on redguard. There's a long dry time required. Other products don't require the long dry time. I use Redguard but also use (Mapei) Aqua Defense which doesn't have the long required dry time.
The plastic behind the rock is really to prevent condensation inside the walls wetting the framing, not so much for waterproofing.
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Here's a thread I did when I built our shower. I didn't use plastic in this one but there might be some helpful info in it.
Shower build
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I like the Redgard type products. They work great and are an affordable way to do a shower. It's been around a really long time and is now starting to fall out of favor with the Schluter Kerdi being the most preferred but that's being pushed by marketing. It's pretty easy to install but pricey for basically a sheet of plastic with fuzz on both sides.
Redgard is what gets used in all the fast food restaraunts we do. The entire bathroom and then the lower part of the walls so mop water doesn't wick up into the walls. Yes tile mud sticks to it just fine. I don't know how but it does.
I will add that when doing a walk in shower I still prefer a typical mud base with a shower pan liner. Now with Kerdi or redgard it isn't needed but I personally like having that little extra protection just in case something leaks.
If you are doing a linear drain in a shower there are only 2 options for using a Kerdi or redgard system when it comes to the drain itself and they are expensive. If you do a linear drain you can save a ton of cash by going with a traditional pan install as the drains are a fraction of the price but you can still do a hybrid and use Kerdi or redgard over the mud base. It won't be perfect around the drain but it would keep the mud base from being a constantly soaked brick all the time.
(basically you can do what Snipe hunter did in his install but you can coat it all in redgard including the mud pan or you can cover it all with Ditra)
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(07-30-2020, 08:42 AM)Robert Adams Wrote: I like the Redgard type products. They work great and are an affordable way to do a shower. It's been around a really long time and is now starting to fall out of favor with the Schluter Kerdi being the most preferred but that's being pushed by marketing. It's pretty easy to install but pricey for basically a sheet of plastic with fuzz on both sides.
Redgard is what gets used in all the fast food restaraunts we do. The entire bathroom and then the lower part of the walls so mop water doesn't wick up into the walls. Yes tile mud sticks to it just fine. I don't know how but it does.
I will add that when doing a walk in shower I still prefer a typical mud base with a shower pan liner. So do I but it may be because I've done a few and it's a lot cheaper. A lot of shower installers are using "tile ready fiberglass pans" now as opposed to the foam products. Not cheap but pretty much foolproof. They can be ordered in custom sizes and stock sizes. More than one has told me that they've had to rip out Kerdi and Schluter bases. They come with the drain installed too. Now with Kerdi or redgard it isn't needed but I personally like having that little extra protection just in case something leaks.
If you are doing a linear drain in a shower there are only 2 options for using a Kerdi or redgard system when it comes to the drain itself and they are expensive. If you do a linear drain you can save a ton of cash by going with a traditional pan install as the drains are a fraction of the price but you can still do a hybrid and use Kerdi or redgard over the mud base. It won't be perfect around the drain but it would keep the mud base from being a constantly soaked brick all the time.
(basically you can do what Snipe hunter did in his install but you can coat it all in redgard including the mud pan or you can cover it all with Ditra).
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I read you should never use both Red Guard and the plastic sheeting, and I won’t.
So it looks like it has some sort of “fuzz” the mortar can lock on to?
My plan is to use it with porcelain tile.
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I put red guard on both of my bathroom remodels, two coats and a third coat the corners and I ran it all the way to the ceiling along with the tile. I also put red guard on first 2 ft of the floor out from the tub and caulked the seam where tub meets the cement board.
In both demos I had to replace subflooring at each end of the tub so I figured it would help. No issues at all with adhesion.