A. Craig Savage responds: Because of its fire resistance, tile is the predominant roofing here in Southern California. On these roofs we’ve done all our skylights using one of two basic methods, both of which have performed well (no callbacks yet).
Membrane and metal. These days most local building codes call for a continuous membrane over the entire roof, with the tile over the top. We commonly use either 90-pound felt or a hot-mop, three-ply built-up roofing for this water barrier.
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