Chimney Flashing is a vital part of your roof. Oftentimes we get emergency leak calls during a winter rainstorm which can be costly for the property owner or Property Management Company. More often than not, we find that the leak is coming from around chimneys and the culprit is the flashing, which is the metal that keeps the intersection between the chimney and roof watertight.
Proper flashing around a chimney includes two layers. The first is called step flashing: L-shaped aluminum are woven into the shingle courses and lapped up the side of the chimney. Next comes the counterflashing: The second layer of metal usually consisting of either lead or copper. It is embedded in the chimney mortar joints and folded down to cover the top of the step flashing.
The corners are especially vulnerable and are usually cut and bent around the corner. Even with a good quality installation, this leaves one small spot that should be sealed with high-quality caulking.
The type of metal used for flashing depends on where you live. Aluminum and galvanized steel are sometimes used. Copper is the longest-lived, but because it’s so expensive, we see it only on higher-end jobs. Another advantage to copper is that the corners can be soldered for a watertight connection.
Crickets-When a chimney is located at the bottom of a roof slope, a cricket (a small diversion roof that prevents water from pooling and ponding behind the chimney and eventually leading to seeping through the roof into the roofing system of your house) should always be installed.
Because chimneys are such a potential trouble spot, inspect them once or twice a year for loose or missing flashing and cracks in the masonry.
Call or email Sully-Jones 800-611-4110 / 619-444-0150 / email@example.com to schedule with one of our professionals for a free roof inspection to provide the roof condition and any needed maintenance recommendations.