Shower room questions

[cab]

I am planning a 8' x 11' shower room in my new home and have a question about the floor. The bathroom is on a first floor, with a 3/4" plywood subfloor over 3"x8"x 10' joists 1 foot on center. I plan to pour a 3" concrete slab on top of the subfloor with radiant heat tubing using a schluter product that insulates and holds the tubing in place. I plan to line the room with the kerdi waterproof membrane. I would like to use this slab as my finished shower room floor. Is this feasible? Should I apply the kerdi to the plywood subfloor and then pour the concrete over it, or would a simply poly sheet under the slab work?

Thanks for any info....

Chris

[frenchie]

It's feasible, but if you want to avoid creating a mold colony, you need to pre-slope under the membrane - not have the membrane flat on the wood & pour over.

[jadnashua]

Kerdi is a tileable waterproofing membrane designed to go on TOP of the sloped floor, then be tiled. If you don't do it this way, you are in for big problems down the line..you may not rot out the woodwork, but you will not be satisfied with the results.

Have you viewed the videos on www.schluter.com (http://www.schluter.com) on the construction of a Kerdi shower?

I'd embed the radiant tubing in a drypack mud floor in the shower area.

Check out www.johnbridge.com (http://www.johnbridge.com) for some tiling help and some more opinions.

I also suggest you call up Schluter and talk to them about the best way to do what you want...I thing it is doable, but you've got some ideas that