A.Patty McDaniel, owner of Boardwalk Builders in Rehoboth Beach, Del., responds: We finish chimney chases with sheet-metal caps made for us at a local metal shop. We've used both galvanized and stainless steel, though we prefer stainless because galvanized will rust after several years in our coastal environment.
For stability against high winds, we typically frame the chases with full-length 2x4 studs that run back to the attic floor level. We sheathe the chimney on all four sides and the top with exterior-grade plywood. The chase gets insulated to the ceiling or roofline, with intermediate fire blocking and air-sealing at each floor level. The interior...
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