What is a roof cricket?
A roof cricket is a raised, sloped structure built behind a chimney or another roof obstruction. Its purpose is to divide and redirect water around the obstruction so rain and melting snow can drain away instead of collecting against it.
On a typical sloped roof, water naturally follows the roof plane toward the eaves. A chimney interrupts that flow. Without a cricket, water may gather on the uphill side of the chimney, especially during heavy rain or snowmelt. A properly designed cricket creates two drainage paths, sending water around both sides of the obstruction.
Roof crickets are usually framed with wood or another structural material and covered with the same type of underlayment and roofing system used on the surrounding roof. They may be visible as a small ridge rising behind the chimney or concealed beneath the finished roofing.
Why are roof crickets important?
A cricket reduces the amount of water that can remain trapped behind a chimney. That matters because repeated moisture exposure can damage flashing, roofing materials, sheathing, insulation, and interior finishes.
The main benefits include:
- Improved drainage: Sloped surfaces move water around the chimney rather than allowing it to pool.
- Reduced snow buildup: A cricket can help divide snow accumulation and reduce the pressure created by a large drift.
- Better flashing performance: Properly shaped flashing is more effective when water has a clear path away from the chimney.
- Lower risk of leaks: Less standing water means fewer opportunities for water to penetrate joints or deteriorated materials.
- Longer roof service life: Keeping the area dry helps protect nearby shingles, metal flashing, and roof decking.
A cricket does not make a chimney completely leak-proof. It is one part of a complete water-management system that also includes step flashing, counterflashing, underlayment, shingles, sealants, and sound chimney masonry.
Where is a cricket installed?
A cricket is normally installed on the uphill side of a chimney, where the roof slopes toward the chimney. It is not usually needed on the downhill side because water is already moving away from the obstruction.
The exact design depends on the chimney’s width, the roof pitch, the roof covering, and the amount of precipitation the structure receives. Wider chimneys generally create a greater drainage problem and may benefit more from a substantial cricket.
Crickets can also be used behind other large roof penetrations or raised structures. For example, a designer may consider one where a broad skylight curb, rooftop mechanical structure, or similar obstruction interrupts a significant drainage path. Small plumbing vents and narrow penetrations generally do not require this type of construction.
How does a roof cricket work during rain and snowmelt?
A cricket works like a small roof within the roof. Its peak is positioned behind the obstruction, and its sloped sides direct water toward the left and right sides of the chimney.
During rain, water reaches the cricket and separates around the chimney rather than flowing directly into its uphill corner. During thawing weather, meltwater follows the same channels. This is particularly useful in East Aurora, NY, where roofs may experience alternating periods of snow, freezing temperatures, rain, and rapid winter or early-spring thawing.
A cricket also affects how snow settles. It may prevent one large, uninterrupted snowdrift from forming directly against the chimney. However, it does not eliminate snow loads or ice dams. Roof valleys, eaves, and areas with limited sunlight can still accumulate substantial ice and snow.
Are roof crickets required on every chimney?
No. A cricket is not automatically necessary on every chimney. Its suitability depends on the chimney’s size, location, roof geometry, and local code requirements.
Building codes and accepted construction practices may call for a cricket on larger chimneys or in situations where the obstruction significantly interferes with drainage. Requirements can vary by the code edition adopted in the jurisdiction and by the specific building design.
For an existing home, the absence of a cricket does not automatically prove that the roof was built incorrectly. Many older homes were constructed with different detailing practices. However, a missing cricket can become a concern if the area behind the chimney repeatedly leaks, collects snow, or shows signs of deteriorating flashing.
What does a roof cricket look like?
From the ground, a cricket may appear as a small raised ridge behind the chimney. Its visible shape depends on the roof covering and the height of the surrounding chimney.
Some crickets are large enough to be obvious from an upper-story window. Others are low-profile and mostly hidden beneath shingles or metal roofing. The visible materials may match the rest of the roof, while the most important components—such as the framing, underlayment, and flashing—remain concealed.
A roof cricket should not be confused with a roof saddle used as a general term for a raised drainage structure. In everyday roofing language, “cricket” and “saddle” are sometimes used interchangeably, although terminology may differ among building professionals and code references.
What problems can occur when a cricket or its flashing fails?
The most common problem is leakage where the chimney meets the roof. Water may enter behind deteriorated metal flashing, through cracked masonry joints, beneath lifted roofing materials, or around improperly sealed transitions.
Warning signs can include:
- Brown or yellow ceiling stains near the chimney
- Damp attic insulation or roof sheathing
- Peeling paint near an upper-floor fireplace
- Soft or discolored wood around the chimney opening
- Rusted or separated flashing
- Loose shingles uphill from the chimney
- Repeated leaks after wind-driven rain or snowmelt
- Moss or unusually darkened roofing materials in the drainage area
A leak does not always appear directly below the chimney. Water can travel along rafters, roof decking, insulation, or framing before entering the living space. For that reason, the visible stain may be several feet away from the actual entry point.
Does a cricket prevent chimney leaks by itself?
No. A cricket improves drainage, but it cannot compensate for damaged masonry or poor flashing.
A chimney roof connection normally relies on several layers working together:
1. Step flashing is installed along the sides of the chimney.
2. Counterflashing is built into or secured to the chimney masonry and covers the upper edge of the step flashing.
3. Headwall flashing protects the uphill side.
4. Underlayment provides secondary protection below the finished roof covering.
5. Roofing materials shed most of the water.
6. The cricket redirects water around the chimney.
If any of these elements is missing, corroded, loose, or incorrectly integrated, water may still enter. Sealant alone is not a dependable substitute for properly layered flashing because sealants can shrink, crack, or separate over time.
What should homeowners check after a storm?
After heavy rain, strong wind, or a snowmelt event, a homeowner can safely inspect visible areas from the ground or from an upper-floor window. Look for displaced roofing materials, exposed metal, unusual water staining, or debris collecting behind the chimney.
Attic inspection can also reveal problems if the space is safely accessible. Look for damp wood, wet insulation, daylight through roof joints, or fresh water tracks. Avoid walking on roof surfaces, climbing onto a steep roof, or approaching icy areas.
Roof work around chimneys involves fall hazards and may require careful integration with masonry and structural components. If active leakage, soft roof decking, damaged flashing, or substantial snow and ice is present, evaluation by a qualified roofing or building professional is appropriate for safety and accurate diagnosis.
A well-designed cricket is easy to overlook, but it performs a practical job: moving water and snow away from one of the most vulnerable roof transitions. In older housing areas, regular observation of chimney flashing, attic conditions, and interior ceilings can help identify drainage problems before they spread into larger structural or moisture-related damage.
