How To Repair Your Roof Valleys & Flashings

How To Repair Your Roof Valleys And Flashing

Roof valleys are areas where two sections of a sloped roof meet. Traditionally, valleys were comprised of galvanized iron or steel to prevent rusting. However, small cracks inevitably appear on the protective layer over time, triggering rust to crop up as soon as rainwater gets in the valley.

In some designs, shingles are overlapped to form a valley, and water from heavy rains can find a way beneath the shingles. In modern roof systems, valleys are typically gutter-like metal troughs made of lead, fiberglass, or concrete. Aluminum is also growing in popularity and provides a lightweight and rust-resistant alternative to traditional iron/steel valleys. 

Valleys Can Degrade Over Time

Naturally, roof valleys undergo wear over time since they’re designated areas that allow rainwater and debris to flow and not build-up on your roof. Just like gutters, valleys can wear, leak, or get blocked up with debris. 

How to Repair Roof Valleys

Roof valley repair is a common situation where you will need the help of a local professional roofing contractor to help with the problem. Valleys in older roofs are often weak spots prone to damage and leaks. Repairing a damaged or degraded valley takes a clean, orderly process to make the results long-lasting. 

Your roofer will begin by inspecting the valley for holes all along the joint. Next, the valley is carefully cleaned using a wire brush to remove any debris. Small holes can be patched with the same type of sheet metal the original valley is made of; using a different metal to patch it will cause corrosion.

In most cases, valleys can be repaired without touching other parts of your roof. However, if the damage extends beneath your shingles, a few shingles can be removed to create room for repair work before being installed back. To replace a roof valley on most roofs, the ridge capping at the top will need to be removed and later reinstated after the valley has been changed. 

Roof Flashing

Roof flashing is a thin sheet of galvanized steel installed to channel rainwater away from important areas of the roof. They are installed in sections where the roof surface meets a vertical plane, such as a dormer or a wall. Flashing is often installed to surround critical roof features, such as skylights, vents, and chimneys. Water should seamlessly run down the side of the flashing and down to the shingles instead of infiltrating the roof deck. Without flashing against vertical walls, water can get into the crevice between the roof and the wall, and potentially into your home.

Flashing Can Degrade

Damaged or poorly installed flashing is among the most common causes of roof leaks. However, flashing can also get damaged or degrade over time, causing leaks in your home. Some of the causes of flashing damage include normal wear, UV light, storm damage, corrosion, and more.

How to Repair Roof Flashing

Corroded spots and small holes in roof flashing can be easily repaired. Your roofer may simply cork pinholes using roofing cement and effectively patch holes using a patch cut out from the same material the flashing is made of.

First, your roofer will roughen the area around the hole using a wire brush or sandpaper and carefully clean it. The patch is then cut to a size larger than the hole and affixed with roofing cement. To effectively seal the hole and prevent future leaks, the patch should be covered with more roofing cement.

Flashing that is severely corroded will, however, need to be replaced. Your roofer will have to remove a few rows of shingles plus the old flashing to do this. Finally, the flashing seals will be renewed by chipping out old mortar and caulking along the edges of your flashing. Special masonry caulk is recommended for sealing the joints between the flashing and the wall, chimney, skylight, or vent. However, silicon caulking compound or urethane roofing cement works well for sealing the seam between stem flashing and roof cap.

A Local, Reputable Roofing Contractor Can Help!

Roof valleys and flashing are simple yet critical components of any roof. Make sure to hire a local, reputable roofing contractor to inspect and repair your valley, flashing, and any other part of your roof. Poorly installed flashing and/or valleys is one of the most common causes of roof leaks, so it’s important to hire a professional with the experience and expertise to do it right the first time. Contact S&S Roofing in Arlington, WA, for all your valley and flashing needs.