Drip edge flashing is installed at the roof’s edge to protect the roof sheathing and ensure rainwater enters the gutter. Drip edges are metal sheets, usually “L” shaped. This flashing’s function is to direct rainwater away from the fascia and into the gutter.
Without drip edge flashing, water may intrude beneath the shingles and will cause damage, include rot, to the roof sheathing.
Your home may not have been constructed with drip edge flashing, but today, most building codes across the United States require this flashing to protect the home from damage.
Purpose of Roof Drip Edge Flashing
Drip edges have two main purposes. The first, is to direct water rainwater into the gutters. If your home is built in an area where gutters are not needed. This drip edge flashing helps direct rainwater away from the fascia. Controlling rainwater is a very important factor in protecting homes in all climates.
The second purpose of drip edge flashing is to protect from wind-driven rain. With heavy wind and rain, the wind pushes water around on a roof. Shingles are there to protect the roof’s deck (sheathing). The edges of the roof are where the wind can up-lift shingles. The drip edge needs to hang significantly off the edge of the roof and have two to four inches of lower flange to combat this. Obviously, without drip end flashing, heavy rain and wind will compromise the roof.
Materials for Drip Edge Flashing
Drip edge flashing is sold of various plastics and metals. With plastic flashings, it is recommended to reserve this material for over windows and doors. Use corrosion-resistant or galvanized metal for roofs.
Common drip edge flashing materials:
Aluminum – sold in colors to match the home and won’t corrode.
Galvanized Steel – Drip edges are designed to be in contact with water. They need to be galvanized to prevent rust. Thicker the better to withstand strong winds.
Copper – Copper is for a more unique look.
Drip Edge Flashing Shapes
Type C – Most common edge flashing is the “L” shape. The drip edge is formed at a 90-degree angle with a lower “kick out” flange and the bottom.
Type D – This type forms a “T” shape, with a lower “kick out” flange. Sometimes it is called, “T-style” or “D metal”. This type is preferred by most asphalt manufacturers.
If your Site Tech Home Inspector recommended drip edge flashing for your roof, you should have it installed before your roof is damaged.