Flashing As Siding

It is used to protect the horizontal joints between sheets of siding from water infiltration.

Flashing as 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 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. 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. Siding is the first line of defense against water intrusion and the multitude of problems it causes including the dreaded mold.

With the flashing in place let s see what happens. 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. Depending on the reveal of your siding the flashing length will be inch less than the reveal. Otherwise dripping water will leave its mark along the siding.

The water then runs off the flashing because it can t go up the flashing as it extends up behind the siding. 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. The following series of pictures will detail how to make a simple flashing that can be slid up behind the joint. Galvanized z flashing so called because of its z shaped profile keeps water from getting through horizontal joints between sheets of plywood siding.

But many builders fail to protect the most vulnerable areas of siding. Galvanized steel z flashing is made from 28 gauge galvanized steel. The large leg of the metal goes against the wall leaving the seat and face covering the top edge of the siding. Continue installing the z flashing at the top edge of the siding panels across the full length of wall.

Failed caulk joint with no flashing behind. Where the step flashing terminates along a sidewall is a common trouble spot for moisture problems. The seat dimension 3 8 in corresponds to the siding thickness. 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.

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. The caulk has failed and water can find its way behind the siding.