What is a chimney cricket?
A peaked roof structure installed behind a wide chimney to divert water runoff and debris away from the roof surface.
A chimney cricket is a small peaked roof built directly behind a chimney where it meets the main roof. Also called a chimney saddle, it has two sloped sides that meet at a ridge, creating a channel that sheds water and debris down either side of the chimney rather than allowing them to pool and dam up behind it.
Water pooling behind a chimney creates serious problems. It backs up under shingles, seeps into the roof structure, and accelerates rot in the framing and decking. Debris accumulates in the same spot, trapping moisture and compounding the damage. On wider chimneys (typically those over 30 inches wide), a cricket becomes especially important because the large profile creates a significant dam across the roof plane.
Ontario roofers typically recommend adding or replacing a cricket if you have a wide chimney with visible water staining, leaks inside near the chimney, or deteriorated flashing around the base. Building code requirements in Ontario often mandate crickets on chimneys wider than a certain threshold, and insurance claims related to water intrusion at chimneys may require one to be installed before a claim is approved.
A cricket is usually built from wood, covered with the same roofing material as the main roof, and flashed where it meets the chimney and roof. Proper installation and maintenance of the flashing seal is critical to its effectiveness.