Has anyone ever seen or heard of using lightweight concrete instead of gypcrete over floor trusses, to facilitate pex? Possible? My concrete guy says they can mix the crete with plasticisers and structural fibers to beef it up. Im thinking 2 inchs topped with either tile or Marmoleum. Before i order trusses this week it would be great to get some feedback. Thanks, Michael

We used two inches of concrete on a plywood deck for our radiant. We did not use light weight concrete.

We just beefed up the joists and put them on 1 foot spacing. It worked great and makes for a wonderfull floor.

PS Structural fibers show in the floor unless polished.

Michael;

 

Dietrich has a great residential (trimable) joist sytem with metal pan / for concrete topping able to clear span over 30 ft.
They have done free engineering for me in the past

What is usually the most cost effective system for radiant, finished concrete floors? I just want a gray smooth concrete finish w/ radiant installed. metal pan systems? speedfloor? litedeck? others?

That will all depend on how much you need to span.

Jmagill, Chris, thanks for the reply. I just wanted to make sure i wasnt making a mistake. Pump truck will be 300 and concrete will be 500 +- but i think it will be worth it in the long run. Thanks again.