my 30 is sitting on tile over concrete slab, has the standard 8 in. legs i think. even though all the legs stand on tile/concrete, the front legs are about 4 inches from a wood threshold and the wood floors. if i put a standard 1.5 r value hearth pad in front of the legs and extend it out to the required 18inches, would i fulfill the spirit of the requirement? as i read it the ambient floor pad is not for radiant heat protection but loose embers and such. if you think it passes, should it be fastened somehow?