Thermal Mass for Radiant Heating

Unknown

is a great place for vermits. sifts through cracks too.

Hey, if you use sand, do yourself a favor, install a 3ft x 3ft piece of 1/2 acrylic instead of plywood. It'll be like a big antfarm!!! Better then TV.

OK, in all seriousness, I know of not one major manufacture who would recommend sand on a build up system.

Sand is only recomended for use in snowmelt or under slabs. In both of these it would be compacted sand (can't do that on a plywood floor). In snowmelt systems iit is used for drainage and would get wet hence increasing conductivity. Under slab it would be used when running high temps.

FYI

wheels

Mark Prince

Thermal Mass for Radiant Heating

Have spoken to a vendor who recommends SAND (leveled over and around pex) as a better and less expensive thermal mass than plates or WIRSBO panels. This is for a system which will be installed over joists & subfloor (which are over an existing slab) on new construction and covered with hardwood floor. Anyone have any experience with SAND?!

John Felciano

Sand

is for the beach not the house!Ever walk on a sandy beach in the middle of summer,Hot? but not as hot as the asphalt.It also cools down alot faster than the asphalt.

Sand is full of little tiny air pockets that make it a bad conductor of heat.Try this,fill a pail with sand than add water.You can get quite a bit in there.Than fill a bucket with cement and do the same.....

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Chris Burt

I have heard about sand also. I would agree it is better than the metal plates or the panels. It is not as good as concrete but that was not an option. You didn't say anything about putting insulation under the floor. Another option could be putting down the sleepers then putting gypcrete I have done that before. Also with the option you are using put extra pipe down and put the tubing closer to 6" or 9" on center. I have mine a 12" and can tell you where the tubes are located when I walk over the floor. The system heats the room fine I would like it if it heated evenly.

Alec

Sand does have a great use, "ant farms" I have seen this installation and it does attract bugs.
Sand is also a great insulator and could crystalise over time dependant on the temps.
Have you seen Wirsbo's Joist track and Quik track awsome stuff.
From below Joist track is the way to go from above Quik track is the way to go why give all that money to a concrete guy.

leo g_24

mark

use to work with a contractor that always buried the underslab tubing in sand. it seems to have made for a more even heat. but this was usually covered by 4-6" of sand. have never heard of it being used as you describe.

from what i read of your description, why not treat it like a normal job? insulate under the joists, run your tubing on the subfloor and pour your 1 1/1" skim?


leo g

Troy_3

sand inside your house

Bad idea. sand breaks down with time and becomes less conductive I have been told. Also as stated it will continue to sift into your house forever. The sand needs to be solidified with some kind of concrete product.