Base Flashings are the portion of a flashing attached to or resting on the deck to direct the flow of water onto the roof covering. A Base Flashing consist of piles of roof membrane material used to seal a roof at the vertical plane intersections, such as at a roof-wall and roof-curb junctures.

What is base flashing used for?

Base flashing is the solution for front walls. Base flashing is one length of flashing that is bent (along the length) to match the pitch of the roof. Base flashing is installed over underlayment, but under siding and shingles, so you may not be able to see it from the ground.

Is roof flashing necessary?

Roof flashing, usually made from metals like aluminum, copper, or steel, is flat and thin, and prevents water from getting under shingles. … All of these areas leave shingles and underlayment vulnerable to water, so the flashing is necessary to prevent leaks.