Repairing Brick Chimney Flashing
Flashing helps to keep water from entering a house around a chimney. If water enters through cracks, seams or gaps and makes it way into a house, water can cause mold, mildew and wood rot. All three conditions threaten the structural integrity of the house because the wood becomes soft and loses its strength. Mold and mildew are dangerous for those in the home. Some molds are toxic, while others are irritants. Mold and mildew also leave the home smelling musty and old. Roofers use a variety of materials as flashing including aluminum, copper, heavyweight felt paper, many layers of tar paper or sheet metal. Keeping the flashing tightly sealed to the roof and chimney stops the water from entering the house.
Tie off on safety lines to keep yourself safe on the roof.
Brush the dirt, dust and debris away from the base of the chimney will a small whisk broom.
Examine the base of the chimney for cracks, splits, gaps or missing sections of flashing.
Pour asphalt roofing cement in a shallow, disposable pan or you can use a squeeze tube or tube of roofing cement that fits into a caulking gun.
Apply a thick layer of roofing cement over the sections that are damaged. Press the roofing cement into the existing flashing with a trowel. Let the roofing cement set for five minutes or so.
Apply a thick layer of roofing cement over the flashing and about 2 to 3 inches out onto the roof and up the chimney until you touch the first mortar joint with roofing cement. Spread and press the roofing cement into the roof and chimney. As you get to the edge of the roofing cement, press it down very firmly to create a watertight seal.
Always check the masonry structure for damage before repairing the flashing.
Check you’re the flashing around the chimney seasonally.
If the flashing is severely damaged, it will have to be replaced. No amount of roofing cement will keep a tight seal.