Customer wants to tile the concrete floor throughout their entire basement. No problem, I said, but I'm wondering if I need a membrane such as ditra between the tile and the concrete, as the little voice in my head's telling me that slapping tile on thinset over concrete is unwise. What do you guys think?
EZ Mode
Over time, expansion and contraction may cause tiles to crack. Depending on how big the area is, you may need an expansion joint.
But troweling down some thinset and Ditra would be a good idea.
The reason why tile lasted so long in places like the ancient Egyptian pyramids is because they poured a layer of sand between the substrate and mortar bed. Much for the same reason as your thinking.
Good idea.
But troweling down some thinset and Ditra would be a good idea.
The reason why tile lasted so long in places like the ancient Egyptian pyramids is because they poured a layer of sand between the substrate and mortar bed. Much for the same reason as your thinking.
Good idea.
I'm planning on using ditra in my bathroom. only because research & advice of some trusted pros on this board....
I'm used to laying over pored slabs & pools. something about the ditra seems "hoakie" to me. though its mechanical properties make a lot of sense. so ditra it will be.
anyone ever pull up ditra?
ty
ray
I'm used to laying over pored slabs & pools. something about the ditra seems "hoakie" to me. though its mechanical properties make a lot of sense. so ditra it will be.
anyone ever pull up ditra?
ty
ray
Let me put it this way-- it never hurts to Ditra the floor. However, if that concrete's been there for years, and there's no real cracks in it, I'd go right on the concrete and not have a problem guaranteeing it. If there ARE any cracks, I'd check them to see if there are any with one side higher than the other. If that's the case, I wouldn't tile it at all, because NO membrane, not even the "legndary" Ditra, will protect the tile from vertical movement.
Ray-- I thought the same thing before I used it the first time. Schluter's rep had come to the local Dal warehouse and shown it to us, and my attitude was "Yeah, right. You got a bridge in your back pocket?" The first time I ever used it, it was due to a recommendation from Dave Taylor at tile-experts.com. There was someone who'd contacted him thru John Bridge's site from Rowley, Mass., who'd had a kitchen floor installed, and the guy came in and stapled 1/4" plywood over vinyl and luan. It took that floor 6 months to fail. So I went in tore out the old floor put down the Ditra and set glazed porcelain with unmodified thinset. There was so much I was doing on this job that went against everything I'd learned about tile to that point, that I had to get it in writing from Dave as well as the Northeast Schluter rep, Bryant Bouchard (the guy in the Kerdi video), that if this floor failed due to anything other than workmanship, they'd back me on it. That was almost 4 years ago, and that customer has already given me several other customers in her area, and I'm about to do a family room for another of her friends this april, so I know for sure that floor has held up fine. One other thing-- a week after that kitchen got tiled, a 450 pound Wolfe gas stove got wheeled across the floor.
The stove:
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Ray-- I thought the same thing before I used it the first time. Schluter's rep had come to the local Dal warehouse and shown it to us, and my attitude was "Yeah, right. You got a bridge in your back pocket?" The first time I ever used it, it was due to a recommendation from Dave Taylor at tile-experts.com. There was someone who'd contacted him thru John Bridge's site from Rowley, Mass., who'd had a kitchen floor installed, and the guy came in and stapled 1/4" plywood over vinyl and luan. It took that floor 6 months to fail. So I went in tore out the old floor put down the Ditra and set glazed porcelain with unmodified thinset. There was so much I was doing on this job that went against everything I'd learned about tile to that point, that I had to get it in writing from Dave as well as the Northeast Schluter rep, Bryant Bouchard (the guy in the Kerdi video), that if this floor failed due to anything other than workmanship, they'd back me on it. That was almost 4 years ago, and that customer has already given me several other customers in her area, and I'm about to do a family room for another of her friends this april, so I know for sure that floor has held up fine. One other thing-- a week after that kitchen got tiled, a 450 pound Wolfe gas stove got wheeled across the floor.
The stove:
You don't have to be. You've never heard of a sand cushioned floor? I've never done it with tile, but I've installed several sand cushioned terrazzo floors. The sand basically goes down just like drypack. The only difference is the cement is missing. It gets wet down just as much, packed, and screaded off the same way.
I've never done it with tile, but I've installed several sand cushioned terrazzo floors. The sand basically goes down just like drypack. The only difference is the cement is missing. It gets wet down just as much, packed, and screaded off the same way.Ditra is fine, but why go through that hassle. ECB membrane for the floor is more than sufficient and installs in much much less time and hassle. Depending on the thickness, not only is it crack suppression membrane, but also can be water proof and sound proof. Great replacement for old cork installations in condo's that have cement floors.
I happen to disagree with bill vincent on the existing cracks or no existing cracks. Thermal expansion area's should be membraned or have expansion joints placed in the floor. Either premade metal with silicone or pure silicone expansion joints. If its a basement and they just don't care or do not have the extra money for membrane..then you can squeak by...but if its not a financial concern, membrane it. Worst case, if there are existing old cracks, then get some wicking paper or even small amount of membrane and cover those. Anything to prevent damage to the new installation for now and later.
I happen to disagree with bill vincent on the existing cracks or no existing cracks. Thermal expansion area's should be membraned or have expansion joints placed in the floor. Either premade metal with silicone or pure silicone expansion joints. If its a basement and they just don't care or do not have the extra money for membrane..then you can squeak by...but if its not a financial concern, membrane it. Worst case, if there are existing old cracks, then get some wicking paper or even small amount of membrane and cover those. Anything to prevent damage to the new installation for now and later.
Ditra is ok . a few things i dont like about it
1 is the additional height added to floor
2 in wet areas where does the water go after gets through the grout and the thinset. answer is no where it sits in ditra channels and starts that horrible process we know as molding.
3 on large applications even an experienced installer can rarely smear thinset and then roll out ditra before overglazing. Not good for bond.
I do however always install a anti-fracture membrane over concrete in basements or smooth troweled concrete most thinsets even the best will shear from a smooth troweled or sealed concrete floor.
Have any of you used ardex yes ardex products for tile install or anti-fracture/waterproofing. there products are awesome maybe better than any i have used. for anti-fracture use ardex 8+9 is two part system you mix and roll or trowel on price is good also.
1 is the additional height added to floor
2 in wet areas where does the water go after gets through the grout and the thinset. answer is no where it sits in ditra channels and starts that horrible process we know as molding.
3 on large applications even an experienced installer can rarely smear thinset and then roll out ditra before overglazing. Not good for bond.
I do however always install a anti-fracture membrane over concrete in basements or smooth troweled concrete most thinsets even the best will shear from a smooth troweled or sealed concrete floor.
Have any of you used ardex yes ardex products for tile install or anti-fracture/waterproofing. there products are awesome maybe better than any i have used. for anti-fracture use ardex 8+9 is two part system you mix and roll or trowel on price is good also.
1) I find an eighth of an inch isn't excessive in most applications.
2) The depressions in the Ditra are quite shallow and "hold" very little water. Anything above this tiny amount will simply not penetrate. The water has nowhere to go. It will evaporate and dry out.
3) With one helper, mixing DitraSet to the proper consistancy and not attempting to spread more than a reasonable area, I have never seen this as a problem.
2) The depressions in the Ditra are quite shallow and "hold" very little water. Anything above this tiny amount will simply not penetrate. The water has nowhere to go. It will evaporate and dry out.
3) With one helper, mixing DitraSet to the proper consistancy and not attempting to spread more than a reasonable area, I have never seen this as a problem.
No, moisture and bacteria caused the mold.
Ditra claims to be waterproof when coupled with its Kerdi Tape.
The "pockets" in the Ditra then act as dishes to store water that seeps through grout lines.
The good thing about durock, and other CBU products is they soak up water, like a spong, not hold it, like a plate.
Ditra claims to be waterproof when coupled with its Kerdi Tape.
The "pockets" in the Ditra then act as dishes to store water that seeps through grout lines.
The good thing about durock, and other CBU products is they soak up water, like a spong, not hold it, like a plate.
You can actuall install tile on a concrete subfloor with a waterproof membrane.
This is especially helpful for slabs with cracks, or lack thereof of expansion gaps running north and east.
Grab you a TCNA 2006 Handbook and read away at all the colorful verbage.
Now I got to set my guinness on top of that very stinkin handbook so I can play GUN on XBox 360 LIVE!
This is especially helpful for slabs with cracks, or lack thereof of expansion gaps running north and east.
Grab you a TCNA 2006 Handbook and read away at all the colorful verbage.
Now I got to set my guinness on top of that very stinkin handbook so I can play GUN on XBox 360 LIVE!
Why argue?
Forums are an awesome source of information. I usually don't go more than three pages into a thread because it's usually two or three guys taking shots at each other. My two cents are to use the membrane. Ditra isn't necessary on a concrete basement floor if you do. I haven't had any call backs when I've used red guard or merkrete. I've never heard of mold problems with ditra, I love the stuff, it just isn't needed in this case. Just read the specs /directions and follow them.
Forums are an awesome source of information. I usually don't go more than three pages into a thread because it's usually two or three guys taking shots at each other. My two cents are to use the membrane. Ditra isn't necessary on a concrete basement floor if you do. I haven't had any call backs when I've used red guard or merkrete. I've never heard of mold problems with ditra, I love the stuff, it just isn't needed in this case. Just read the specs /directions and follow them.
I have a feeling this is more a problem of GEOLOGICAL location. From what I've read in all the forums over the last 5 years or so, it seems like I may have been blessed with living in an area with a relatively stable ground, where installing directly over concrete really isn't a big deal in most cases, and the times that it IS a big deal, the slab usually reveals itself by the time it's cured. But I've talked to people like John Bridge, whose soil down there in Houston is loaded with clay, and anyone setting over raw concrete should have their head examined, or those contractors out there in California, where the ground gets restless every once in a while.
I guess my point is it depends on where you are, and what the soil is like where the project is, as to whether you can trust the slab or not. In the last few years, I've only run across 2 slabs that I felt it necessary to membrane the entire slab. Normally, I'll use Laticrete's 9235 with 24" strips of fabric as a crack suppression membrane, just over the cracks, and that keeps the floor intact. I DO understand, however, that there are areas in this country where the slab would chew that up and spit it out.
I guess my point is it depends on where you are, and what the soil is like where the project is, as to whether you can trust the slab or not. In the last few years, I've only run across 2 slabs that I felt it necessary to membrane the entire slab. Normally, I'll use Laticrete's 9235 with 24" strips of fabric as a crack suppression membrane, just over the cracks, and that keeps the floor intact. I DO understand, however, that there are areas in this country where the slab would chew that up and spit it out.
merkrete
We have switched to the merkrete roll on crack iso on every job that we do. I just got done doing 500 feet today. For us in ohio its the best stuff out there, roll it on with a paint roller and go home. Its ready to set in the morning. I takes half the time and i wouldn't be setting tile anyways today if i used anything else because it would take me all day. So for us Its about time and energy. We can roll it one and move on to the next thing. I have heard no problems around here but i would be interested in hearing form others.
We have switched to the merkrete roll on crack iso on every job that we do. I just got done doing 500 feet today. For us in ohio its the best stuff out there, roll it on with a paint roller and go home. Its ready to set in the morning. I takes half the time and i wouldn't be setting tile anyways today if i used anything else because it would take me all day. So for us Its about time and energy. We can roll it one and move on to the next thing. I have heard no problems around here but i would be interested in hearing form others.
Besides Ditra, what are some anti-crack membrane choices?
Besides Ditra, what are some anti-crack membrane choices?
I have heard of cheap alternative such as using liquid roll-ons, tar-paper, and landscape fabric.
What really works for less than Ditra for existing hairline cracks?
:confused1:
Besides Ditra, what are some anti-crack membrane choices?
I have heard of cheap alternative such as using liquid roll-ons, tar-paper, and landscape fabric.
What really works for less than Ditra for existing hairline cracks?
:confused1:
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