Chimney Cricket

A chimney cricket is a framed and flashed structure that creates a small ridge behind a chimney. Instead of allowing water to flow directly into the back of the chimney, the cricket splits the flow and directs it around both sides before it continues down the roof.

Without a cricket, rainwater, melting snow, leaves, and other debris can collect behind the chimney. Over time, this buildup increases the risk of leaks, ice dams, and premature wear of the roofing materials.

Although homeowners may never notice it from the ground, a chimney cricket is an important part of many roofing systems.

When Is a Chimney Cricket Needed?

The International Residential Code generally requires a chimney cricket on chimneys that measure 30 inches or more wide, as measured perpendicular to the roof slope.

Even when a chimney is smaller than 30 inches, a cricket may still be recommended depending on:

• Roof pitch

• Roof design

• Amount of water flowing toward the chimney

• Surrounding roof features

• Manufacturer recommendations

A professional roof inspection can determine whether a chimney cricket is required or beneficial.

How Does It Work?

A chimney cricket works much like the bow of a boat cutting through water.

As rain or melting snow flows down the roof, the cricket divides the water and directs it around both sides of the chimney. This helps prevent water, snow, leaves, and debris from collecting behind the chimney where leaks are more likely to develop.

The cricket is then covered with roofing materials and flashing so it becomes part of the complete roofing system.

Typical Cost

A chimney cricket is typically included as part of a roof replacement when required by building code or recommended based on the roof design.

The cost depends on the size of the chimney, roof pitch, framing requirements, and roofing materials being installed.

Although it adds to the scope of the project, it provides valuable long-term protection against water intrusion.

Benefits

• Directs water around the chimney

• Reduces the risk of roof leaks

• Helps prevent debris buildup

• Reduces snow and ice accumulation

• Improves roof drainage

• Helps protect chimney flashing

• Supports long-term roof performance

Why It Matters in Michigan

Michigan's heavy snowfall, spring rains, and freeze-thaw cycles can cause significant amounts of water and snow to collect behind chimneys.

A properly installed chimney cricket helps keep water moving around the chimney instead of allowing it to pool behind it. This helps reduce the risk of leaks, ice dams, and moisture damage while improving the performance of the entire chimney flashing system.

Our Recommendation

At VanderLaans, we inspect every chimney during a roof replacement to determine whether a chimney cricket is required by code or recommended based on the roof design.

When needed, we build and flash the cricket as part of the complete roofing system so it works together with the shingles, step flashing, and counter flashing to provide long-term protection.

Did You Know?

Many chimney leaks don't begin at the front of the chimney, they begin behind it, where water and debris collect. A properly designed chimney cricket helps keep water moving, reducing stress on the flashing system and helping protect one of the most leak-prone areas of your roof.