Roof Underlayment Flashing Detail

Synthetic underlayment and ice barrier membrane readily fold at this wall to roof joint.

Roof underlayment flashing detail. Details roofing wrb flashing. Protect the eave from ice dams and sideways rain step one in steep slope roofing is the edge flashing. Valley flashing for roofs. Usually you won t see much of drip edge as it s under the roof shingles under the underlayment and behind the roof gutter.

We describe how to construct three common styles of roof valley. This article discusses details and specifications for roof valley flashing for best construction roof leak resistance. In every case the top edge of the flashing passes underneath the underlayment the upper pieces of flashing pass over the lower pieces and the lower edge of the flashing always passes over the top of the roofing material. Install your underlayment completely and your shingles up to where the wall begins so that the first piece of flashing or the corner flashing will rest on a shingle.

A roofer has cut the housewrap at the joint between the roof and the wall folding it back so that he can lap it down over the underlayment and step flashing as the author recommends. Open valley closed cut valley and woven roof valley and we include roof valley underlayment and nailing specifications. Our photo above shows what we ask of roof edges. But where no gutters are installed you might get a peek.

One common method is to lay the edge metal under the eaves membrane and over the rake.