On Sun, 07 Jun 2009 19:23:59 GMT, Franz Fripplfrappl
wrote:


Will Durock or other cement board atop subflooring provide sufficient
thermal mass for radiant floor heat?

I initially had planned to staple up the tubing with heat transfer
plates beneath the floor and between joists. Now I'm thinking of
putting the tubing on top of the subfloor and build up the spaces w/
durock with a layer of durock on top for tiles.

Usually the decision is based on accessibility.

I would think that under the sub floor would result in the
most even heating and long term comfort. However the above sub floor
installation would likely deliver heat to the room faster. I am
considering an installation in my master bath and I would want the
quicker heat because I would not have it on full time.