Do You Cover Flashing on a Roof?

Flashing Types

• There are two basic styles of roof flashing. One is used to cover joints, where a roof meets a wall or connects with another roof line or to cover the peak of a roof. The other is installed at roof edges and is called drip edge or edge cap. All flashing is installed after the roof decking is put on and at the same time roofing felt, paper or other waterproofing membrane is applied.

Basic Flashing

• Basic flashing is thin metal, typically 6 to 8 inches wide, which is bent to seal a joint. Where a roof meets a wall or another roof line, flashing is bent so one side goes down the roof and the other goes under the wall siding or the other roof. On a peak, flashing is bent to go down both sides from the top. In both uses, flashing typically is nailed into place before roof paper or membrane is applied. That goes on top of the flashing, but under the shingles.

Edge Flashing

• Edge flashing comes in various styles. Basic drip edge is metal bent at 90 degrees so one edge goes on the roof, the other down a facing board. Drip edge is installed on the eaves, the bottom of a slope, under the underlayment; roofing paper goes on top of it. On the rake or angled edge of a roof, the drip edge goes over the underlayment.

Covering

• All flashing is covered by shingles or final roof covering. It typically is nailed in place, often with a bead of roofing cement underneath as added protection against water. Shingles typically cover the flashing up to where it connects with a wall. On a peak, shingles go on the peak to cover both flashing and roofing paper bent over the top. On edges, shingles go to the edge of the roof and drip edge extends slightly beyond to direct water away.