Transition Roof Tin Over Porch

Screw the steel hex washer head screws into the tops of corrugated waves of tin roofing material to prevent leaking through screw holes at the bottoms of the waves when rain runs down the roof.

Transition roof tin over porch.

A roof pitch transition is a line in the roof plane that changes pitch. This is a fairly common roof detail. The roof plane goes from one pitch to a lower pitch. 4 inches should go up the house wall and 4 inches should go on top of the porch roof shingles.

Step 6 make a 10 degree bend on the shingle edge of the flashing approximately 1 2 inch from the edge. Attach 3 by 3 foot sheets of tin to each section of the frame using 1 inch steel hex washer head screws and a cordless drill. We see this quite frequently in log home roofs with porches for example. Use the metal break tool to bend the flashing lengthwise in the middle according to the angle of the roof joint.

After that to make it flush with the roof of the existing house cut the two outer rafters. We re going to install it over top of the panels that have already been installed on the lower slope. Attach the horizontal beam by using a nail gun. The piece that allows us to join the two different slopes is the pitch transition trim.

This allows water to flow off the upper panels out over the trim onto the lower panels and exits the roof at the eaves. See the illustration below. Most flashing is 8 inches wide.