I'm building cabinets for a Wolf 6 burner gas range. It is going to be installed in an island with cabinets next to and behind it. Someone told me I needed non-combustible material behind the range, is this true? The cabinets on the sides are wood and I know there is no issue with that. I previously had it up against a wall with drywall behind it. Since its now an island with a cabinet behind it too will that be an issue? It will have granite counter top all around, so I'm not concerned above the counter, just below. Is there any code issues I need to be aware of? I'm in San Diego, CA. thanks