There's plenty of material available about how to flash windows and patio doors, but most of it seems to cover flanged units. Nearly every house I build, though, includes at least one "flangeless" unit — typically a standard entrance door with an applied brick-mold casing. The tricky part about flashing cased units is sealing the area where the back of the casing meets the housewrap. And door units present an added challenge: Since there's no sill flange, wind-driven rain has a straight shot at penetrating the area immediately below the threshold.
In this article, I'll explain how I use self-healing membrane to fabricate flashing flanges for the jambs and heads of cased units, and a flexible membrane to form a one-piece sill pan.
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