Your chimney plays an important role in ventilating your home and removing harmful gases and smoke. That's why proper chimney maintenance is vital to keep it working effectively. Chimney crickets can help by offering much-needed protection.
What Are Chimney Crickets?
A chimney cricket, also known as a chimney diverter or saddle, is a raised roofing structure built to direct water away from the chimney. When this essential feature is missing, pooling water and animal infestations can build up around the chimney. So, you should install a chimney cricket to keep your roof (and chimney) in good working order.
Benefits of Chimney Crickets
Chimney crickets offer several advantages, all of which help support healthy roofing systems.
Prevents Pooling Water
The main purpose is to divert water away from the chimney so it doesn't pool in this area. Since it's often installed on the high side of the chimney, its positioning and design divert any water to the sides that would otherwise flow onto the masonry. Per ICC 1503.5, crickets must be installed on any chimney or penetration wider than 30 inches (762 mm) perpendicular to the slope.
Extends the Life of Roofing Systems
The intersection where the roof meets the chimney is often vulnerable. Your home could experience leaks and water damage if moisture infiltrates the roof structure below. Pooling water can also deteriorate roofing materials like shingles, flashing, and masonry. Chimney crickets can help prevent these issues and keep your roof and chimney well protected, supporting their longevity.
Keeps Critters Out
Animal deterrence is another strong benefit of installing a cricket. Since pools of water can attract small animals like squirrels, birds, insects, and raccoons to the area, chimney crickets can help deter them. Covering the intersection between the chimney and roof reduces the likelihood of smaller animals entering through any gaps.
Avoids Debris Buildup
Since this roofing structure also diverts debris, it helps keep your chimney and roof clean, improving overall ventilation. A cleaner chimney means better airflow circulation and ensures dangerous smoke and gases leave through it without issues.
Chimney Cricket Construction
Chimney crickets can be composed of different materials and built at different sizes based on the roof slope and chimney width.
Materials
A chimney cricket typically includes a wood frame as its structure and metal—aluminum, galvanized steel, or copper—for its body.
Aluminum and galvanized steel are the most affordable materials. Aluminum doesn't rust, but it doesn't offer the same robust construction as steel or copper, and heavy impacts can damage it more easily. Meanwhile, galvanized steel provides excellent weatherproofing and impact resistance, but it's prone to rusting.
Copper is a premium material that can resist rust and offer a long lifespan, but it's also the most expensive cricket material.
Alternatively, the surface of the saddle can be covered with roof shingles so it blends in seamlessly and maintains the same finished look. Flashing is then installed around the cricket to further weatherproof the areas where it meets the roof and chimney.
Design
Each chimney cricket should feature specific design characteristics. For starters, they need to measure at least 6 inches up to the back of a chimney. The ridge needs to be at least 12 inches, and the flange should be at least 18 inches up the roof deck.
According to the International Residential Code, a chimney should use a chimney cricket if it's width is longer than 30 inches along the ridgeline side. These are the guidelines you should follow based on your roof slope:
Roof Slope — Height of Chimney Cricket
12:12 — 1/2 of Width
8:12 — 1/3 of Width
6:12 — 1/4 of Width
4:12 — 1/6 of Width
3:12 — 1/8 of Width
For example, if you're installing a cricket on a chimney that's 5 feet wide and the roof slope is 8:12, the cricket height should be 1.6 feet.
Common Chimney Cricket Issues
Chimney crickets should work effectively once installed. But like all roofing materials, wear and tear can add up after many years of use.
Leaks
If you spot water leaks or stains around the walls near your chimney, it can indicate problems with the cricket. Sharp winds can lift a poorly installed cricket, flying debris from storms can damage the area, and the flashing between the chimney and cricket can crack over time. Depending on the chimney saddle material, corrosion and rust can also weaken the structure. All of these issues allow water to reach the vulnerable points of a chimney and roof.
For masonry chimneys, it's important to note that the effectiveness of the flashing is only as good as the condition of the masonry above it. Cracks or loose mortar in the masonry can allow moisture to penetrate behind the flashing, potentially deteriorating the chimney cricket.
Pest Intrusions
Animals can also cause damage by attempting to chew through the material or clawing at it. Small critters like mice can try to burrow around the roofing materials, which can loosen it from its place. Over time, this can reduce its effectiveness.
Keeping Chimney Crickets in Good Health
If you notice any of these issues, it's often best to hire a professional to fix them. They might need to climb on the roof to assess the full extent of the problem or reinstall or replace your chimney cricket or flashing. Regular roof inspections can also help spot these issues as they start to show up.
And if you don't already have a chimney cricket, consider investing in one. Compared to the small effort of installing and maintaining one, a cricket can have huge benefits for your roof. It can prevent costly repairs and ensure a safe and efficient chimney system.
Interested in learning more? Reach out to a trusted GAF-certified contractor* to discuss your situation and explore the quality materials that can keep your roof functioning effectively for years to come.
*Contractors enrolled in GAF certification programs are not employees or agents of GAF, and GAF does not control or otherwise supervise these independent businesses. Contractors may receive benefits, such as loyalty rewards points and discounts on marketing tools from GAF for participating in the program and offering GAF enhanced warranties, which require the use of a minimum amount of GAF products. Your dealings with a Contractor, and any services they provide to you, are subject to the GAF Contractor Terms of Use.
