Roof Vent Flashing Over Or Under Felt

Drip edges on the eaves any valley liners and all flashing should be installed before the tar paper is laid.

Roof vent flashing over or under felt.

According to most building codes and manufacturer recommendations the drip edge should be installed beneath the underlayment along the eaves of the roof. Step flashing fits to each course of shingles and appears to step up the wall of the chimney. They re applied under roofing felt along eaves and over roofing felt along rakes. Depending on the width of the pipe you may need to tear away a segment or two of the rubber boot.

Use roofing nails to install the l shaped flashing flush with the roof and wall then cover it with roofing cement and reattach the roofer s felt. After this lines should be snapped every 34 as you move up the roof. Once you have installed shingles just past a plumbing vent install the flashing piece so it will lie on top of roofing at its bottom but be covered with roofing at its top. At the end of the vertical sidewall the step flashing shall be turned out in a manner that directs water away from the wall and onto the roof and or gutter while this is a nice diagram of how these flashings work don t forget our 5 th design rule.

If the felt butts into a wall that has flashing on it and the wall is running perpindicular to the felt the felt is typically placed under the flashing. Step flashing protects the joints between the roof deck and chimneys or dormers. Chalk lines should be snapped 33 5 8 above the eave line. This material is available with a v or w shaped profile and is placed over the top of the building felt before the roof s finishing material is installed.

The flashing shall be a minimum of 4 inches 102 mm high and 4 inches 102 mm wide. Flashing is installed to surround roof features such as vents chimneys and skylights. Continuous flashing protects the joint between a vertical wall and a sloped roof. Then the felt would be under the flashing.

Cap flashing mortared or caulked into the chimney laps over the top edges of the other flashings to prevent water from running behind them. Drip edges prevent water from seeping under roofing along the edges of rakes and eaves. But over the underlayment along the rake edges of the roof. 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.

Lay it over metal flashing edges around vents and pipes. Before laying roof felt all rotten decking must be replaced. Fit felt around vent pipes or other protrusions by cutting it with a utility knife and fastening around the bottom of the vent. Begin by removing the shingles at the affected area and removing old flashing if present.