This is an old thread - but what jumps out to me is that you can't use a metal roof for shade because it will collect and radiate the heat. In Central Texas a corrugated steel roof will get hot enough to burn you. I make roofs out of plywood with shingles - but even then it is best to keep the hutch in the shade. If you have no shade then make the roof over a foot larger each way than the cage - and have 3 feet of air space between the floor and the roof. Cement stepping stones stay cool in the shade, and make good resting platforms when it's hot.
