What is a Roof Cricket?
How Roof Crickets Improve Commercial Roof Drainage
Water is one of the biggest threats to a commercial flat roof. Although these roofs may look flat from the ground, they should be designed with enough slope to move rainwater toward drains, gutters or scuppers.
The challenge is that rooftop equipment, walls, and other obstructions can interrupt that path. Water can collect behind an HVAC curb, along a parapet wall, or between drains. A roof cricket helps redirect that water before it becomes a long-term drainage problem.
Understanding what a roof cricket does and what happens when it is missing or poorly designed can help facility managers identify drainage concerns before they lead to leaks, wet insulation, and premature roof deterioration.
What is a roof cricket?
A roof cricket is a raised or sloped section of a roof designed to direct water around an obstruction or toward a drainage point. It is sometimes called a saddle because its shape can resemble one.
On a commercial low-slope roof, crickets are commonly constructed from tapered insulation or other materials beneath the roof membrane. The membrane is then installed over the shaped area to create a continuous, waterproof surface.
A roof cricket does not drain water by itself. Instead, it changes the direction water travels so the main drainage system can carry it off the roof.
Where are roof crickets commonly installed?
Roof crickets are often found:
- Behind large HVAC units
- Between closely spaced rooftop curbs
- Along parapet walls
- Between roof drains
- Near skylights
- Around large penetrations
- In valleys where water naturally collects
- Near chimneys or other raised structures
Any rooftop feature that blocks the natural flow of water may require a cricket or another drainage detail.
Why do commercial flat roofs need crickets?
Commercial roofs often contain HVAC units, vents, pipes, hatches, skylights, and other equipment. Each component can create an obstacle that water must move around.
Without a properly designed cricket, water may:
- Collect behind equipment
- Remain along flashing
- Increase pressure on seams
- Carry debris into drains
- Accelerate membrane deterioration
- Enter through small defects
- Saturate roof insulation
A cricket helps reduce these risks by keeping water moving.
Are flat roofs actually flat?
Most commercial flat roofs are technically low-slope roofs. The slope may be created by the structural deck, tapered insulation, or a combination of both.
The roof should direct water toward:
- Internal drains
- Scuppers
- Gutters
- Downspouts
Even a roof with an appropriate overall slope can have isolated low areas. Building settlement, compressed insulation, poorly placed equipment and previous roof work can all alter drainage.
That is why drainage should be evaluated across the full roof, not only at the drains.
How does roof cricket installation work?
The exact method depends on the roof assembly and the obstruction.
On many commercial roofs, a contractor uses tapered insulation to create the cricket. The insulation is cut and arranged to form slopes that guide water around the obstruction. A cover board and roof membrane may then be installed over the new shape.
A good roof cricket design should account for:
- The size of the obstruction
- Existing roof slope
- Direction of water flow
- Distance to the drain or scupper
- Membrane type
- Flashing heights
- Curb elevations
- Expected rainfall
- Roof traffic
The cricket must work with the roof’s drainage plan. Simply creating a raised area without considering where the water will go can move the problem rather than solve it.
What are the signs of a poorly designed roof cricket?
A cricket may not be working correctly if you notice:
- Water remaining behind rooftop equipment
- Debris collecting along one side of a curb
- Waterlines on membrane or flashing
- Repeated leaks near the same obstruction
- Sagging or compressed insulation
- Cracked seams near the cricket
- Water being redirected toward another low area
- Ice repeatedly forming in the same location
In some cases, the roof cricket is present but too small, too flat, or pointed in the wrong direction. In others, the surrounding roof has changed since the cricket was installed.
Can ponding water damage a commercial roof?
Ponding water does not automatically mean a roof will fail, but it should not be ignored. Standing water can expose the membrane and flashing to prolonged moisture, collect dirt and debris, and increase the consequences of small defects.
The additional weight may also matter when water is deep or spread across a large area. In cold climates, repeated freezing and thawing can add stress around seams and drainage components.
Most importantly, ponding can be a symptom of:
- Poor slope
- Blocked drainage
- Compressed insulation
- Deck deflection
- Building settlement
- An undersized or poorly placed cricket
Read more about ponding water on commercial flat roofs.
Can a roof cricket stop an existing leak?
A cricket may be part of the solution when drainage contributes to a leak, but it will not repair wet insulation, open seams or damaged flashing by itself.
The existing leak should be investigated first. A complete repair may require:
- Locating the water-entry point
- Mapping or removing wet insulation
- Correcting damaged membrane and flashing
- Improving slope with a cricket
- Confirming water can reach the drain
If the leak is coming from the HVAC unit, wall or another building component, changing roof drainage alone may not solve it.
What is the difference between a cricket and a scupper?
A cricket redirects water across the roof. A scupper allows water to pass through a wall or edge and leave the roof.
The two components may work together. A cricket can direct water toward a roof scupper, while the scupper carries it away from the roof surface.
Problems can develop when either component is blocked, undersized, damaged, or positioned incorrectly.
Should a cricket be added during roof replacement?
Roof replacement is an ideal time to evaluate drainage because the contractor can inspect the existing assembly and redesign tapered insulation where necessary.
Before approving the new system, ask:
- Where does water collect now?
- Will new insulation change curb heights?
- Are drains and scuppers correctly placed?
- Does the new design create positive drainage?
- Are the crickets large enough for the obstructions?
- How will water move if a primary drain becomes blocked?
Correcting drainage during replacement can help protect the new roof from recurring problems.
Can an existing roof cricket be repaired?
Sometimes. If the membrane or flashing is damaged but the underlying shape is appropriate, targeted repairs may restore performance.
If the slope itself is inadequate, the area may need to be opened and rebuilt. A roofing contractor should evaluate the membrane, insulation, deck and surrounding drainage before recommending a repair.
Do not ignore where the water goes
A roof cricket may look like a small detail, but it can have a major effect on commercial roof performance. When it is correctly designed, it helps water move around equipment and toward the drainage system. When it is missing or ineffective, water can repeatedly collect in the same vulnerable areas.
Weather Shield Roofing Systems helps commercial building owners identify why water is ponding, where it should go and which repair will provide lasting value. We evaluate the entire drainage path, not only the most visible low spot.
If water is collecting around rooftop equipment or your building has a recurring leak, schedule a commercial roof inspection. We will document the condition and help you understand the most practical next step.
Patrick Renkes
Patrick Renkes is an Account Executive at Weather Shield Roofing Systems, serving the Lansing, Michigan region. He brings over 30 years of leadership and problem-solving experience, helping commercial clients make confident, informed roofing decisions. With a background spanning automotive, property management, and executive leadership, Patrick is known for delivering practical solutions that extend roof life and reduce long-term costs.
