Flashing is the metal or plastic covering that goes around the chimney to prevent water from seeping through where the chimney meets the roof. Over time, due to general wear and tear and weather exposure, the flashing can become damaged or loose, allowing water to enter your home, opening the door to water damage and mold and mildew growth, a serious health concern. Thankfully, repairing damaged chimney flashing is a fairly simple process that does not require a significant investment of time or money with the right tools and know how.
What You'll Need
You'll need a chisel, roofing cement, a hammer, masonry nails (or masonry screws and an impact drill), and a putty knife, all of which are available at most hardware stores. You will also need a ladder to get up onto the roof, and someone to spot you while you climb to ensure that the ladder does not slide.
Avoid repairing the chimney flashing on a rainy day, as rain can make roof work dangerous and can inhibit the roofing cement from setting properly.
Repairing Chimney Flashing
Climb up onto the roof and find where the flashing has separated from the chimney.
Remove any leaves and other organic detritus that has built up within the gap between the chimney and the flashing.
Use the chisel and hammer to remove the hardened roofing cement that is still attached to the chimney. Throw away the broken chunks of cement.
Use the putty knife to apply roofing cement liberally on the chimney behind the flashing.
Then, use the hammer and masonry nails (or the masonry screws with the impact drill) to reattach the flashing tightly to the chimney. After you install the nails or screws, cover their exposed heads with roofing cement to prevent them from corroding over time due to weather exposure.
Apply roofing cement to the edge of the flashing, where it meets the brick. Smooth the roofing cement out using the putty knife to ensure a watertight seal that will prevent the flashing from separating further.
Let the roofing cement sit for a few hours to dry, and then re-examine your work. Check for any gaps in the roofing cement that may allow water to seep between the flashing and chimney, and fill any gaps or holes with roofing cement. Ensure that no screw or nail heads can show through as well, and cover up any that do.
To learn more, contact a company like Skerlec Contracting.