I just got a dumerial boa from a friend. She is about 5'8, so a good size adult. My friend is moving and they are taking the cage for their new fish (reptiles not allowed in new place). Anyway, I have a 48 gallon cage to get by for now. I do own 3 other snakes: ball python and two corns. I want to build my own cage for the boa to get proper size. I want to make it 4'x2'x18". What should I use for the flooring so I can use an under the tank heater?