DuPont™ Tyvek® DrainWrap™ and Window Installation


Animation of installation over a wood framed, sheathed wall with proper flashing at window (using FlexWrap™ NF on sill, StraightFlash™, WrapCaps and 3″ Tyvek Tape), Penetration and attachment at base of wall. 1:35

Step 1: Cover the joint where the sheathing meets the foundation with Tyvek Flashing tape. Tape should be placed 2/3 on sheathing and 1/3 on foundation wall. (Concrete may require primer for maximum tape adhesion).

Step 2: Apply metal base flashing and seal w/ caulk or tape to initial flashing tape.

Step 3: Apply a bead of caulk along the top of the OSB.

Step 4: Always working from the bottom up, fasten the DrainWrap to the sheathing w/ weatherproof fasteners. Cover 2/3 of the drip edge flange and skip tape in place. Seams should have a minimum 6″ overlap and sealed with 3″ tape.

Step 5: Cut weather barrier in an “I-cut” pattern. A modified I-cut is also acceptable.

Step 6: Fold side and bottom weather barrier flaps into window opening and fasten.

Step 7: Cut a head flap at 45-degree angle in the weather barrier membrane at window head to expose 8 inches of sheathing.

Step 8: Cut DuPont™ FlexWrap™ at least 12″ longer than width of sill rough opening (S) and press into place. Do not stretch the FlexWrap.

Step 9: Apply continuous bead of DuPont™ Weatherization Sealant at the window head and jambs to wall or back side of window mounting flange. DO NOT APPLY SEALANT ACROSS BOTTOM SILL to allow for drainage.

Step 10: Install window according to manufacturer’s instructions.

Step 11: Cut two pieces of DuPont™ StraightFlash™ or DuPont™ FlexWrap™ for jamb flashing extending 1″ above window head flange and below bottom edge of sill flashing.

Step 12: Cut a piece of DuPont™ StraightFlash™ or DuPont™ FlexWrap™ for head flashing, which extends beyond outer edges of jamb flashings.

Step 13: Start flashing at bottom of penetration. Shingle upper tape over bottom tape.

Step 14: Using Tyvek Seam tape, secure DrainWrap in place.

Step 15: Secure window trim and wall cladding.