Roof Flashing: Where Most Roof Leaks Start

Roof flashing is the metal or rubber that seals the joints on your roof: where the roof meets a wall, where a pipe or chimney comes through, and where two roof slopes meet in a valley. Shingles shed water well across a flat run. The joints are where water finds a way in, and that is why most of the leaks we find start at flashing.

The kinds of flashing on your roof

• Pipe boots: the rubber collars around plumbing vent pipes. Sun breaks down the rubber, it cracks, and water runs down the pipe.
• Wall flashing: metal pieces where a roof runs into a wall, such as the side of a dormer or a second-story wall.
• Chimney flashing: metal around the base of the chimney, with counterflashing set into the brick or siding above it.
• Valley flashing: the lining in the valley where two slopes meet and the most water on the roof flows.
• Heat stacks and HVAC collars: flashing and rain collars around furnace and water heater flues.

Chimney flashing

Chimney flashing seals the joint where a chimney comes through the roof. It usually has two parts. Step flashing is tucked under the shingles along the sides. Counterflashing is set into the chimney and laps over the step flashing, so water cannot get behind it. Wide chimneys often have a cricket, a small peaked section on the uphill side that steers water around the chimney.

Signs of a flashing leak

• A water stain on the ceiling under a bathroom vent, a chimney or a wall that meets the roof.
• Cracked or split rubber around a vent pipe.
• Caulk standing in for flashing, or flashing that is pulled away from a wall.
• Rust or lifted metal around a chimney.

Arkansas heat and sun are hard on rubber pipe boots, and hail and wind loosen metal. A flashing leak can run along the deck before it shows up inside, so the stain on your ceiling is not always right under the problem.

What flashing repairs cost

We publish our repair prices. On a standard-pitch roof, one-story home:

• Replace 1 pipe flashing: $786
• Flash or counterflash up to 5 feet of wall: $786
• Reflash up to 8 linear feet of chimney: $1,038
• Repair up to 10 feet of valley: $1,038

Steeper roofs and two-story homes cost more, and each price is for one line item. See every line on our roof repair cost page.

Flashing on a new Patriot roof

Our Guardian and Defender packages include lifetime pipe flashing, and every package includes ice and water shield in the valleys and at penetrations. See the full package list on our roof prices page.

Frequently asked questions

Can I just caulk my flashing?

Caulk is a short-term patch. It dries out in Arkansas sun. A real fix replaces or reseats the flashing so it sheds water on its own.

Is a flashing repair guaranteed?

Once all recommended repairs are done, your roof is covered by the 365-Day Patriot Leak Free Guarantee.

Think you have a flashing leak?

Book a repair visit. The diagnostic visit is $79.99, and Patriot Care Club members pay no service fee. Our phones are answered live 24/7.