Roof Flashing 101: What You Need to Know

Roof Flashing Materials

Most flashing is made of galvanized steel, but in some areas, materials such as copper are used to match the shingles’ appearance better while still being strong, durable and able to withstand the outside elements.

Another option for roof flashing is aluminum. This is lightweight and flexible, but it must be coated to prevent corrosion if it’s going to be used next to concrete.

Roof Flashing Sealant Types

The primary use of flashing is to prevent water from getting into gaps and causing leaks. For this to be achieved, it must be properly installed with a good seal between the exterior walls and the roof.

Some common sealants used when installing flashing include butyl and polyurethane. These can create a waterproof seal that’s flexible enough to hold the flashing in place even if it expands and contracts with the changing weather.

Roof Flashing Types

There are a few main flashing types, each serving a different purpose. 

Step Flashing

Step flashing is a piece of rectangular flashing with a 90-degree bend. This is often installed against a wall. This type of flashing is usually installed in layers to ensure the water flows away from the wall. The layers direct water away from the more vulnerable wall materials.

Counter Flashing and Base Flashing

Counter flashing and base flashing are installed together, usually around areas such as a chimney. The counter flashing is placed above or opposite the counter flashing. The purpose of the base flashing is to catch rainwater and direct it downward and away from the brick or edges where the chimney meets the roof.

Two pieces of flashing are used in this scenario so that the flashing will work year-round. Roofing materials tend to expand and contract with the changing seasons, and flexibility in the flashing helps prevent leaks and damage to the sheet metal and roof surface.

Continuous Flashing

This style of flashing is also known as apron flashing. This long piece of metal directs water away to the shingle below. As with counter flashing, long pieces of sheet metal may be unable to flex and expand to cope with changing temperatures. For this reason, this type of flashing usually has expansion joints or is broken into segments as part of the installation process.

Drip Edge Flashing

The term drip edge refers to thin metal flashing fitted around the property to help water run off the roof without causing dampness or damage.

Valley Flashing

Valley flashing is used on open roof valleys to stop water leaks. This part of the roof can easily leak if it’s not sealed correctly, and installing flashing is an effective way of preventing damage.

Skylight Flashing

Another area of roofing that’s vulnerable to water damage and leaks is skylights. While flashing is often supplied with skylights, some people prefer to replace the supplied flashing products with something installed by a professional roofer so they can be confident it’s been properly installed.

Kickout Flashing

Kickout flashing bridges the gap between the roof and the gutters, ensuring water reaches the gutters so it can flow through them and be directed away from the property. Properly functioning gutters are essential for protecting your siding and walls. If your gutters are broken or coming away, consider investing in gutter replacement along with new kickout flashing.

Common Reasons Roof Flashing Failure Occurs

One of the most common reasons roof flashing failure occurs is wear and tear. The flashing faces the risk of corrosion from exposure to the elements and material stress from settling foundations or seasonal weather changes. Even small gaps in the sealant, whether caused by poor installation or normal wear and tear, may be enough to allow damaging water penetration. Still, the sealant itself may also crack or break.

The good news is that damaged flashings don’t necessarily mean you need a new roof. If the damage is caught quickly, it’s usually possible to repair damaged flashing segments or replace flashing around the affected area.

Signs of Failing Roof Flashings

Some common signs it’s time to consider replacing your flashing include visible rust and corrosion on the flashing, as well as holes in the shingles or sealant. Other signs include cracked or damaged metal and damp patches suggesting a small leak in the roof.

Those damp patches may not be limited to the attic. If you have a skylight or fireplace in your living room, look at the wall or ceiling for any telltale signs of water penetration. If you notice any signs of damage or leaks, call a professional for roof repair as soon as possible.

Get a Professional Roofer Today

If you’re looking for a roofing professional to install or repair roof flashing on your Maryland home, call us now at (240) 222-1453, or use our contact form to request a call back from one of our roofing experts.