A. If the framing won’t support the weight of concrete tile, my choice of roofing in a hot climate would be fiber-cement shingles. These are becoming more widely available and seem to provide a long-lasting roof without adding much weight. Fiber-cement shingles weigh just a little more than architectural-grade asphalt shingles (approximately 400 pounds per square when installed).
There are two ways to handle the insulation problem. The first method is to install a urethane foam insulation board and a new plywood deck over the existing sheathing (see illustration). In warm climates, a second possibility is to install a new roof deck on 2x2 sleepers over the existing sheathing, with a radiant barrier between the old and...
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