radiant with thermafloor question

Gasper

Getting conflicting direction on how to install....put down sleepers first? tubing first? Is a 1/8" to 1/4" gap between gypcrete and floor ok? Is a 3/8" plywood and a 3/8" quartersawn 5" cheery floor on top of the sleepers ok and stable (no sags, transmit heat, etc) ok? Lot's of questions....sorry.

Gasper

Someone............anyone?

troy_8

Gyp between sleepers

Patrick- This is what we found works best. 2"x2" sleepers nailed and glued on 16"centers. Tube between the sleepers on 8" centers. When pouring the gypsum concrete you screed it with a rubber floor squeegee. This keeps the sleepers clean and keeps the gyp close to the top of the sleepers. Do not push down to hard. You don't want an air gap below the finished floor. Depending on the floor being nailed down and the installer you will find that nailing on 16" centers will send most wood installers running off the job. That forces them to glue between the wood sleepers and nail into the sleepers. This is why it is so important that the gyp height is even with the wood sleepers.We have been forced to over fill and then sand down the entire floor to achieve a flat surface for the wood installers. It isn't fun but better if it is figured out in advance with all parties present. I've personally done over 50 of these and some as large as 5000 sq. feet.

jp_2

is gypcrete

really needed?

troy_8

Gypcrete

The gypcrete acts as a thermal mass. The other option is a version of aluminum transmitter. Tube alone in my climate would not work well. The advantage of the gyp is- It is quiet. All dry systems have some noise associated with them. I know everyone denies it and no one has ever heard their systems make even a tiny expansion. Well- sorry- I still say that Gyp is by far the quietest system. And no I don't any longer pour Gyp. I mostly install dry systems now. For a nail down wood floor system we recommend Raupanel. That is if the gyp option is too labor intensive for you.

Gasper

gyp

Thanks for your help. Seems only to be 2 companies in my area that do gypcrete. One guy that seems fair priced, knows his stuff, etc. doesn't think they can match exactly the top of the sleepers. He says the minor gap is minor on performance. he did say they could do a second skim pour (obviously jumping up the price. What do you think about 8" centers of 2" x 2"s? Thanks
PS Anyone in the southeast Michigan area?