Garage Slab

[Riverjet502]

Hey guys I have a 20x24 garage on a piece of property I bought. Of course the garage is just way to tiny! So I was thinking of selling the garage for a buck. (save me the cost of tearing it down and hauling it to the land fill). I want to build a 24x40 to replace it. I was thinking of putting approximately 8 inches of sand over the existing slab with a electric grid, and 4 in thick foam boards along the footings, then pouring my new slab over the old. Just wondering if the old slab would try and pull the heat downward? Acting as a heat sink??? instead of radiating upwards through the new slab??? Thoughts??

 

[bimmer1980]

yes, some of the heat will radiate downward...

The old adage, "heat rises" only applies to fluids that can move--air, water, etc.

As a rule, heat will radiate to a colder area, therefore the heat will radiate in all direction from the heating tube. I'm assuming that you are planning to use heat tube in the floor?

You could put a layer of foam board over the old slab and then pour a full depth slab. 4" or thicker.

Rebar would be better than steel mesh.

Make sure that the sub base is well compacted.

best of luck!