Transition Roof Tin Over Porch

The roof plane goes from one pitch to a lower pitch.

Transition roof tin over porch.

A roof pitch transition is a line in the roof plane that changes pitch. See the illustration below. After that to make it flush with the roof of the existing house cut the two outer rafters. You have to do it thoroughly so that the rafters sit flush on it.

This allows water to flow off the upper panels out over the trim onto the lower panels and exits the roof at the eaves. Make a cutting on one of the sides of the horizontal roof beam on an angle. Use the metal break tool to bend the flashing lengthwise in the middle according to the angle of the roof joint. 4 inches should go up the house wall and 4 inches should go on top of the porch roof shingles.

This is a fairly common roof detail. We see this quite frequently in log home roofs with porches for example. 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. Attach the horizontal beam by using a nail gun.

Step 6 make a 10 degree bend on the shingle edge of the flashing approximately 1 2 inch from the edge. Most flashing is 8 inches wide. Pitch transitions are a common roof detail.