I built a custom cage kinda like yours and used thin vinyl to cover the bottom for cleaning purposes and also to cover up the heat pad... I used flexwatt which supposidly never gets higher than 95 degrees so that isnt hot enough to burn the vinyl or the wood... On the other hand if your using like a zoomed heat pad or others you find in pet stores those get like 115+ degrees so thats a possibility... Either way all heating elements should be hooked up to a thermostat to ensure nothing serious happens... a snake burn or even worse your house burning down. Check out my gallery and youll see some pics of my cages...

Good work on making that cage! Looks real sweet and I like what you did with the doors being rounded and what not. Looks like a light bulb in the back?? Might wanna consider getting that outta there cause lil snakies love to climb on stuff and thats a burn waiting to happen... Lemmie know if you got any other questions and Ill try to help ya out... I think im one of the only ones whose built a special cage for thier BPs but I could be wrong.

Can the rock hide idea and get 2 zilla hides... Pending size you can prolly get 2 for the price of 1 rock hide.