My Sulcata is 16 yo, around 60 lbs. We are in Ohio & his indoor pin is within our shed. The current pin has a combination of OSB, plywood, insulation, & floor has dirt on top. There's also a separate protected box inside with sheet metal sides where we have the heater. This year he has started to dig out his floor, going thru the layers. Need to change his flooring and looking for ideas. Thinking of putting down a horse stall mat so the moisture from his urine and spilled water doesnt soften the wood. How have others built their Sulcata floor & kept them warm?