b'Proper Flashing -Divert. Drain. Dry.Regardless of whether a window is installed in a brand new opening or an existing opening, the installation must be inte-grated into the wall to allow water to be diverted from coming into the cavity and therefore into the interior. Water thatenters the cavity must be allowed to drain; and moisture trapped in the wall or cavity between the window and the fram-ing, must be allowed to dry to prevent mold, mildew and rot. Simple: Divert, Drain and Dry.This goal is accomplished through proper flashing which not only blocksthe infiltration of water, but also islapped in such a way that the waterAdditionaldrains down, and then to the outside. FlashingOverlapsAn integral part of a properly flashed Windowopening is the sill. Moisture can enter BuildingPaper Slipsthe cavity from outside and also from Underinside. FlashingWraps OverWhen the outside is colder than the Jambsinside, the inside air will carry a lotand Sillmore moisture, and since warm airmoves towards cold air, the warm, moist interior air will makes its way into the wall where it will condense outthe moisture.This moisture, in the wall, when theopening is properly flashed, will makesits way down the sides of the new win-dow towards the sill, where the sill con-figuration should allow this moisture toexit.For the moisture that may be left to be prevented from causing problems, the cavity must be allowed to dry. This is accomplished by not completelysealing the full perimeter of the new window/wall interface allowing the space and materials to properly dry.There are two basic methods of flashing:Method A where the Weather ResistiveBarrier is applied after the window ismounted, and Method B where it isapplied before window mounting.The bottom line is divert the environ-mental water, drain any that makes itsway inside, and dry whatever is left.Window Fitters Guide to Window Installation172020 AWDI, LLC Do not reproduce without permission'