You’ll notice every home on the block has flashing on its roof. This is because flashing is an integral part of the roofing system. Flashing helps protect roofs from moisture or water damage, especially sloped roofing systems.
Without roof flashing, you may be subject to roof leaks, moisture, mold, and algae growth over time. It’s best to have a professional install and maintain your home’s flashing for the best results.
How Roof Flashing Works
Flashing is meant to protect against water intrusion. With a sloped roofing system, the flashing is installed at the valleys, dormers, and anywhere an exhaust pipe is present.
In these areas, routine caulking would be ineffective. The water and weather would eat right through the material. Therefore, we add flashing.
Typically, flashing is galvanized steel, aluminum, or copper. It’s also not uncommon to find nonmetal flashing, such as rubber or plastic.
Types of Flashing
- Valley Flashing – Valley flashing is the most common type. We insert it between the outer layer and underlayment, where the two planes join together. Furthermore, valley flashing has an inverted T-shaped profile to ensure rainwater flows downwards.
- Continuous and Step Flashing – Often used on dormers and walls that connect to the roof. Continuous flashing is horizontal and installed on a side facing the gutter system. Step flashing is installed on the sloped side in “steps.”
- Drip Edge – Drip edge is a common type of flashing used on the roof edge. Its inverted L shape helps to prevent rainwater from entering the roof deck.
- Vent Pipe Flashing – Vent flashing is a type of “rubber boot” or cone-shaped flashing installed around the base of an exhaust vent.