Other than adding a finished look to your flat roof, flashing serves a critical role in keeping your roof watertight. Flashing also prevents wind and insect damage. Unfortunately, flashing is one of the most commonly ignored roofing components. Here is everything you need to know about flat roof flashing to help you appreciate its importance in keeping your roof waterproof.
Types of Flat Roof Flashing
Regardless of the pitch of your roof, flashing is installed around edges, along walls, in valleys, around chimneys, skylights, vent stacks, and other roof intrusions. Roof flashing can be made from a variety of materials, including:
- Galvanized Steel
- Zinc Alloy
- Stainless Steel
- Roofing Felt
Most types of flashing are non-staining and non-corrosive, but some types must be mixed with the right kinds of metal to prevent corrosion. When choosing your preferred flashing material, be sure it is completely compatible with your existing roofing material, including fasteners and other roofing components.
How Roof Flashing Works
Flashing protects against moisture and water seepage in a variety of ways. When correctly installed, flashing will control how far wind-driven rain can travel. It should stretch far enough underneath your roofing system and siding to ensure no water seeps into your underlayment.
Flat Roof Flashings
On flat roofs, edge flashing does more than just prevent leaks. After applying the roofing membrane, metal flashing is installed around the roof’s edges in such a way it covers both vertical and horizontal edges. This helps to prevent wind-driven rain from seeping underneath the roofing membrane. It also prevents damage to the edges of your flat roof during high winds.
Since rainwater can still make its way under the horizontal edge of the flashing, a second layer of flashing is often installed to cover the horizontal seam between the metal flashing and the roofing membrane. This extra layer is usually an adhesive rubber membrane which effectively seals both the flashing and the roofing membrane. The flexibility of the rubber membrane means it won’t tear or crack due to thermal expansion.
Are you planning to install a flat roofing system? Be sure to pay close attention to the type of flashing your roofer installs. At Imperial Roofing, we have years of experience installing flat roofs for Tampa, FL residents. Contact us today to learn more about our flashing systems or to get an estimate on any roofing service.