Latest Discussions : Flooring & Stairs


10:39AM | 07/12/07
Member Since: 07/11/07
1 lifetime posts
We bought 6 boxes of this from Lowes and plan to install in the master bath.

Nailed to the joists I have 3/4" OSB and I will install 1/2" hardybacker board. We also want to install Suntouch electric radiant heat mats.

My question is: what thinset should we use for the marble tile and still be able to install radiant heat? Lowes salesperson says we should use adhesive mastic -but then we could not install the radiant...

Any help would be much appreciated. Thanks.


05:23PM | 07/12/07
Member Since: 07/03/05
283 lifetime posts
The salesperson is an idiot.

You need to use a modified thinset, white in color so it does not bleed through the stone tile and stain it. Mastic is not recommended for setting stone or any tile bigger than 8x8, and I would never use it under a floor tile.

I usually use a 1/4" cement board under the heating mats and 1/2" around the perimeter of the room to act as a dam. I then pour self leveling cement over the mats to encapsulate them. It also gives me a nice flat surface, important when you are setting tile with a narrow grout joint as any imperfections in the floor will cause the tile to rise up and rock on the high spot.

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