Thinset for porcelain tile over Ditra
bergsteiger1
| Posted in General Discussion on
I am using the Ditra uncoupling membrane for the first time for a small (100 square foot) tile job. The Schluter website says it is fine to use MODIFIED thinset to adhere the Ditra to the plywood subfloor, however they specify UNMODIFIED thinset to adhere the tiles to the Ditra. The trouble is, I can’t find a source for unmodified thinset – at least the my usual sources (HD, Lowes, and my local building supply). I did find it on Amazon but they want $50 per bag and it seems I would need 2-3 bags just for this small space. What I am wondering is whether unmodified thinset is very different than regular brick mortar, because I can easily find that locally. I’d appreciate any comments. Thanks.
Replies
You probably shouldn't use regular brick mortar. You can get CBP custom blend which is unmodified at home depot but it's more a base for blending your own, I wouldn't use it. There are many brands and types you can use. Bostik Ditra-Set is very good. Mapei has kerabond and kerabond T. Lowe's might be able to order that for you. Schluter makes modified and unmodified mortar that they approve for Ditra. Depends on who supplies what in your area. You need a tile supply place. $50 for that mortar is a rip-off.
I live in kind of a remote area, but I'll check with any tile supply folks I can find in the area. I may just have to travel a bit farther. Thanks for the help.
You need to looked for bagged powdered thinset from a specialized tile retailer.
The same bagged powder is used for both "modified" thinset and "unmodified" thinset. The only difference between unmodified and modified is the liquid additive--which the retailer will also have.
Water is added to the bagged powder to make UNmodified. A white liquid, which is latex based, is added to the powder to make it modified.
Simply purchase the bagged powdered thinset and a container of the white liquid additive. For the UNmodified, use water. For modified, use the white liquid. It's that simple.
I just found a Capco Tile Supply place that isn't too far away that says they have unmodified thinset so I guess I am all set. Many thanks to both of you for your input.
Here is the problem, Ditra is a waterproof membrane. Some modified thin sets will dry properly between Ditra and porcelain tile, but not all will. Some modified thin sets will require a greatly extended drying time. Schluter has tested their modified thin set to make sure it works properly and will dry within a reasonable amount of time. They have not, will not, test or make recommendations of modified thinset products which they do not produce. If you want the guarantee that they provide with the Ditra, follow the labeled directions. Call Schluder customer service, they are very good, they may be able to hook you up with a local distributor.
Thank you