I found these 4'x 8'x 1/4" or so wall panels at Lowes. It seems to be very condensed particle board with a sealant or something with a hard plastic coating on one side. They come in many different patterns from brick to plain white. I was thinking of using this plain white or granite for lining the interior of my custom enclosure stacks using aquarium safe silicon to attach to the inside wood or wood glue and beading the corners with the silicon for sure.
I still encounter heating problems or Im just over looking obvious solutions or just not sure of my thoughts 
. Im thinking ceramic heaters with custom bulb covers to prevent any incidents but in some of my shorter enclosures no type of bulb heating is possible only 1' high enclosures so animal would be to close to bulb cover for my taste. Only thing I can think is UTH heating but not sure if this would mess with my interior lining idea? Cut out over sized square in plywood and place the UTH on the bottom of the paneling. Do you see any problems from this? I guess thats it for now. Any advice is greatly appreciated.
Thanks,
Geoffrey A.
Note - I am not very good at sealing wood so I like the lining method .
