Flashing As Siding

Galvanized z flashing so called because of its z shaped profile keeps water from getting through horizontal joints between sheets of plywood siding.

Flashing as siding.

Otherwise dripping water will leave its mark along the siding. The large leg of the metal goes against the wall leaving the seat and face covering the top edge of the siding. Even if the roof has been properly flashed against the sidewall this one hasn t water can still run down the side of the house and behind the siding causing rot. The water then runs off the flashing because it can t go up the flashing as it extends up behind the siding.

The caulk has failed and water can find its way behind the siding. Failed caulk joint with no flashing behind. It requires no nails. But many builders fail to protect the most vulnerable areas of siding.

The solution to rotting sidewalls is a small piece of bent metal called a kickout flashing at roofing suppliers which simply directs all that water away from the wall. Building siding flashing finish details for building corners use overlapping 1x4s or 1x6s at outside corners or use 5 4 stock for a heavier look. Flashing between brick and siding is a relatively similar process on all types of brick to siding transitions although there may be slight variations based on manufacturer recommendations. You set flashing upon top edge of each piece of plywood over a fat bead of caulk and hold it in place with just heads of roofing nails driven into sheathing.

The best solution is a preformed or custom bent kick out flashing to divert the water away from the siding. Depending on the reveal of your siding the flashing length will be inch less than the reveal. Use a felt paper spline wrapped around the corner and extending 6 inches beyond the corner board to protect the joints where the siding meets the corner boards see figure 1 5 at left. Galvanized steel z flashing is made from 28 gauge galvanized steel.

The water runs down the siding and at the bottom of the first row of vinyl siding it drips off and contacts the metal flashing as it runs across the top of the fascia board. Position the flashing lengths as defined in step 2 overlapping the ends a minimum of 2 inches onto the previous flashing piece and securing the flashing with 8d nails at each wall stud. Siding is the first line of defense against water intrusion and the multitude of problems it causes including the dreaded mold. Where the step flashing terminates along a sidewall is a common trouble spot for moisture problems.

Continue installing the z flashing at the top edge of the siding panels across the full length of wall. It is used to protect the horizontal joints between sheets of siding from water infiltration.