What Are Roof Crickets and Why They Matter for Roof Drainage

Roof crickets are small, peaked structures installed behind chimneys, valleys, or other obstructions to divert water and debris. They are a critical yet often overlooked element of roofing systems that prevent pooling, leaks, and accelerated deterioration. This article explains roof crickets, how they work, common materials, signs they are needed, installation considerations, maintenance tips, and code implications to help homeowners and professionals make informed decisions.

Feature	Quick Detail
Definition	Small ridge or saddle that diverts water around obstructions
Primary Purpose	Prevent water pooling and direct runoff to gutters
Common Materials	Plywood substrate, metal flashing, roofing membrane
Typical Lifespan	Matches roof system if properly installed (15–50 years)

What Is A Roof Cricket?

A roof cricket, sometimes called a saddle, is a raised triangular or peaked structure built on the high side of a roof obstruction, such as a chimney or skylight. Its primary function is to split and redirect water flow away from the obstruction toward the roof’s drainage points, preventing ponding and seepage at vulnerable junctions.

How Roof Crickets Work

Crickets create a change in slope that shifts water flow. On a pitched roof, the cricket forms a small ridge that channels water from the high side around the obstruction to the low side where existing flashing and gutters can handle the runoff. Properly designed crickets reduce hydrostatic pressure and potential infiltration at seams and flashings.

Where Roof Crickets Are Used

Common locations for roof crickets include behind chimneys, at the back of parapet walls, behind skylights, around HVAC curb penetrations, and in valleys where two roof planes meet. Any roof obstruction that creates a water-shedding interruption may need a cricket to prevent chronic wetting of the roof assembly.

Types And Materials Of Roof Crickets

Crickets can be built with several materials and finishes depending on roof type and budget. Typical components include a framed substrate, a continuous waterproof membrane, and metal flashing.

• Framed Substrate: Plywood or roof sheathing shaped to form the ski-slope ridge of the cricket.
• Waterproofing Membrane: EPDM, TPO, PVC, modified bitumen, or built-up roofing systems used to ensure watertightness.
• Metal Flashing: Galvanized steel, stainless steel, or copper used to tie the cricket into adjacent roof flashings and prevent leaks.

On steep-slope roofs, crickets are often covered with the same shingle material or metal cap to match appearance and durability. Selecting compatible materials ensures the cricket’s lifespan aligns with the roof system.

Design Considerations And Dimensions

Cricket size and slope are proportional to the obstruction and roof pitch. Building professionals recommend a minimum slope of 33% (about 18.5 degrees) for effective drainage on low-slope roofs, but steeper crickets are used on high-pitched roofs. A cricket should extend far enough to prevent water from funneling back toward the obstruction—typically measured as a proportion of the obstruction width.

Signs A Roof Needs A Cricket

Visible indicators that a roof may need a cricket include chronic leaks near chimneys or curbs, signs of water staining on interior ceilings or walls, moss and algae growth near obstructions, and visible ponding or gutter overflow. Inspectors often recommend crickets when flashing details appear inadequate or when historical leaks have occurred.

Costs And Installation Factors

Cost varies by roof complexity, materials, and local labor rates. A simple shingled cricket behind a chimney on a steep roof may be relatively inexpensive, while a custom metal-flashed cricket on a commercial low-slope roof will cost more. Typical installation costs can range from a few hundred dollars for a small residential cricket to several thousand for large or commercial systems.

Key installation factors include substrate preparation, slope accuracy, membrane continuity, and integration with existing flashing. Poorly integrated crickets are a frequent source of leaks, so experienced roofers should handle the design and installation.

Maintenance And Repair

Regular maintenance extends cricket life and prevents failures. Recommended tasks include clearing debris, inspecting flashings for corrosion or separations, checking membrane adhesion, and monitoring for signs of standing water. Prompt repair of damaged flashing or membrane laps reduces the likelihood of interior damage and costly emergency repairs.

Common Problems And How To Avoid Them

Problems associated with crickets include improper slope, poor flashing integration, trapped debris, and incompatible materials that cause corrosion. To avoid these issues, follow manufacturer guidelines, use compatible metals and fasteners, and ensure the cricket ties into existing drainage paths. Design reviews during roof replacement projects help ensure crickets are sized and flashed correctly.

Building Codes, Standards, And Best Practices

Building codes and roofing standards do not always mandate crickets, but industry best practices from organizations like NRCA and local building authorities influence their use. In many jurisdictions, crickets are considered required for chimneys wider than a specified measurement or where roof slopes are too shallow to shed water effectively. Consulting local code requirements and a licensed roofing professional ensures compliance and proper performance.

When To Replace Or Upgrade A Cricket

A cricket should be evaluated during roof replacement or when a system shows signs of aging. If the cricket’s membrane, flashing, or substrate is deteriorated, replacement at the time of roof overhaul is cost-effective and reduces future leaks. Upgrading material—such as switching to rigid metal flashing or a more durable membrane—can increase longevity and reduce maintenance.

Cost-Benefit Of Installing A Cricket

Although installing a cricket adds upfront cost, the return often comes through avoided leaks, reduced interior damage, extended roof life, and lower long-term maintenance. For vulnerable roof penetrations, a properly installed cricket is an economical risk mitigation measure. Homeowners should weigh the cost of a cricket against potential repair bills from unchecked water intrusion.

Inspection Checklist For Roof Crickets

• Visual Condition: Look For Corrosion, Tears, Or Displaced Flashing.
• Slope And Drainage: Confirm The Cricket Is Channeling Water Away Effectively.
• Seams And Laps: Ensure Waterproof Membrane Laps Are Intact And Properly Sealed.
• Debris Clearance: Remove Leaves, Shingles, Or Other Blockages Regularly.
• Attachment Points: Check Fasteners For Corrosion And Proper Penetration.

Frequently Asked Questions About Roof Crickets

Do All Chimneys Need A Cricket?

Not always; the requirement depends on chimney width, roof pitch, and historical drainage behavior. Wider chimneys and shallow roof slopes commonly require a cricket to prevent pooling.

Can A Cricket Be Added To An Existing Roof?

Yes, a cricket can be retrofitted, but the process requires careful integration with existing flashing and membrane to avoid leaks. Retrofitting is best done by experienced roofers who can ensure watertight transitions.

How Long Should A Cricket Last?

When installed with quality materials and maintained, a cricket should last as long as the roofing system. Properly detailed metal flashings and membranes can provide decades of reliable service.

Are Metal Crickets Better Than Shingle Crickets?

Metal crickets are often more durable and provide superior water shedding, particularly on low-slope roofs. Shingle crickets can match appearance on steep roofs but may trap moisture if not detailed correctly. Material choice should reflect roof pitch, exposure, and desired longevity.

Key Takeaways For Homeowners And Professionals

Roof crickets are a small but essential component of effective roof drainage. They prevent concentrated water flow and reduce the risk of flashing failures and interior damage. Proper design, material selection, and installation are critical to a cricket’s success, and periodic inspection will ensure continued performance.