Flashing A Roof Dormer

Roof dormer flashing details mistakes snafus.

Flashing a roof dormer.

Add a hole and improper flashing from a recent roof installation to the mix and the water had an open invitation to run into the house. In this article veteran remodeler mike guertin shows how to flash a dormer with bombproof details. Drip edge metal valley flashing dormer chimney and kickout flashing are types of roof flashing that shed water away from the connections between roofs walls chimneys and other building assemblies. Anywhere surfaces intersect on a roof is a prime spot for water seepage.

Proper installation of flashing and counter flashing at the intersection of a vertical wall with a roof surface is required to avoid roof leaks. Flashing is installed to surround roof features such as vents chimneys and skylights. Roof flashing is a thin material usually galvanized steel that professional roofers use to direct water away from critical areas of the roof wherever the roof plane meets a vertical surface like a wall or a dormer. The extra kick at the bottom of the face directs run off away from the structure.

Flashing provides the extra protection these spots need. Lay a bead of roofing cement along the shingles just below the dormer and bed the metal base flashing into it. Tim healey to protect this vulnerable juncture from water intrusion and rot install solid blocking at the eaves to provide a substrate for peel and stick flashing then install the flashing shingle fashion to protect against water ice and snow. While the gold standard for roof flashing is soldered copper the fact is that for economic reasons the vast majority of roof flashing is done with aluminum.

Just as the source of a water leak can be difficult to detect the solution to solve it is usually multi faceted. These problem areas include the edges of skylights and chimneys soil stacks vent fans and roof valleys as well as the intersection of the roof deck and dormer walls. In this case an uninsulated dormer made it easy for moisture to seep inside.