The Purpose And Application Of Roof Flashing

There are a lot of different components to a roofing system, and for those not working in this industry it can be a bit complicated to sit down and have a conversation with a roofing contractor.

One of the roofing components we typically recommend to change with new roofs and roof repairs is the flashing. Since most people aren’t aware of what flashing is, what it does, and how it is applied, we thought it might help to provide some basics.

What is Flashing?

Flashing is typically a metal, often aluminum or galvanized steel, but it can also be made from a flexible, rubberized material with an adhesive backing. Metal flashing can be covered or exposed, but the flexible flashings are always covered.

The purpose of flashing is to stop leaks in areas where there are joints in the roof or in walls . It is used to deflect the water away from the joint to prevent leaks. The most common locations for flashing on a roof are in the valleys, around any pipes or vents that are on the roof, next to chimneys, or around skylights and dormer windows if your home has these additional design elements.

Over time flashing can come loose or become damaged, allowing water to leak into the roof deck and into the home. It can also wear in weather and result in the same leaking problems.


During new construction roofing jobs the appropriate type of flashing is used to provide that extra protection around structures on the roof as well as in the roof valleys. Most roofers will custom cut flashing to match the specific vent, area, or valley, and there are different techniques used for different types of applications.

The edges of the flashing will be sealed using a waterproof sealant and the galvanized or aluminum flashing will be secured in place with nails and then shingles applied over the top. With current flashing repairs, it is possible to nail and reseal existing flashing or remove the required shingles and replace the flashing when repair isn’t possible.

At StormForce of Jacksonville, we are always happy to explain in the necessary details to our customers just what we are recommending and why. If you have any additional questions about flashing, how it is installed, or how it protects your home or commercial building, get in touch with us, and we would be happy to provide you with the answers you need.