Locobreath's comment on spark producing devices in a garage is valid.The National Electric Code says anything below 18 inches is a potential explosion hazard.Same goes for any type of furnace,get it up off the ground.If you have a fire,and make an insurance claim,the the insurance carrier may limit your claim if they find electric or heating devices in violation of the codes even if the device was not responsible for the fire.That goes for extension cords substituted for fixed building wire ,sloppy or incorrect wiring and no ground fault protection for hand power tools.
Heated concrete floors are not too popular here although the winters are severe.Beyond the extra installations costs,it seems broken underfloor tubing from shifting of the concrete is a factor.
