In commercial roofing, proper drainage is essential for protecting the roof system from ponding water, leaks, membrane deterioration, and structural damage. Crickets and saddles are roof components designed to direct water toward drains and prevent water from becoming trapped between drainage points. Their design is especially important on large or complex commercial roofs where multiple drains, curbs, equipment, and changes in elevation can interrupt natural water flow.
What Are Roof Crickets and Saddles?
A roof cricket is a raised, tapered structure installed behind or between roof obstructions to divert water around them. A saddle is a similar sloped feature used to create positive drainage and direct water toward designated drains or drainage areas.
Although the terms are sometimes used interchangeably, their exact configuration depends on the roof design, obstruction location, drainage layout, and applicable building requirements. On commercial low-slope roofs, crickets and saddles are typically incorporated into the insulation or tapered insulation system rather than simply placed on top of the finished roof membrane.
How Are Crickets and Saddles Designed Between Drains?
When two or more roof drains serve a drainage area, crickets and saddles can be designed to establish clear drainage paths between them. The basic principle is to divide the roof into drainage areas and create positive slopes leading toward the appropriate drains.
A cricket or saddle may be positioned at a high point between drains so that water flows away from the obstruction or high point and toward the surrounding drains. The slopes should be coordinated with the roof’s overall drainage plan, insulation thickness, structural deck, and finished membrane.
For example, if two drains are located on opposite sides of a roof area, a properly designed tapered insulation layout can create a ridge or saddle between them. Water then moves down the designed slopes rather than collecting in a low area between the drains.
Why Proper Slope Matters
Commercial low-slope roofs still require effective drainage. A roof that appears relatively flat can experience significant water accumulation if the drainage system and tapered slopes are not properly designed.
Crickets and saddles help provide positive drainage, meaning water is directed toward drains rather than left in depressions. This can reduce the risk of:
- Ponding water
- Roof membrane deterioration
- Leaks around seams and penetrations
- Insulation damage
- Excessive structural loading
- Premature roof replacement
The exact slope should be determined by the roof designer based on the project conditions, applicable code requirements, manufacturer’s specifications, and the selected roofing assembly.
Design Considerations for Commercial Roofs
Designing crickets and saddles between drains requires more than simply adding tapered insulation. The roofing professional should consider the roof deck slope, drain locations, roof dimensions, insulation system, parapets, penetrations, rooftop equipment, membrane type, and expected rainfall.
Drainage calculations should also account for the size and capacity of roof drains and associated drainage components. The design must ensure that water has a continuous path to an adequately sized drainage point.
On large commercial buildings, multiple drainage zones may be necessary. Each zone should be carefully coordinated so that water does not become trapped by a cricket, saddle, curb, or other obstruction.
Final Takeaway
Crickets and saddles between roof drains are designed to create controlled drainage paths and prevent water from becoming trapped on commercial low-slope roofs. They are generally formed using tapered insulation or another properly engineered roof assembly, with high points positioned to direct water toward drains. Proper design requires coordination between the structural deck, insulation, roof membrane, drainage system, and applicable building requirements.
For a commercial roofing project, a qualified roofing professional should evaluate the existing drainage pattern and design crickets, saddles, and tapered insulation according to the specific roof configuration. Properly planned drainage can improve roof performance, reduce ponding, and help extend the service life of the commercial roofing system.
Related Questions
- What’s the difference between a cricket and a sump?
- How does tapered design affect drain and scupper placement?
- What is the difference between tapered edge strips and a full tapered system?
- Does the Florida Building Code mandate crickets behind curbs above a certain width?
- What is a zero-slope or reverse-slope condition and how is it fixed?
- What documentation should the tapered design supplier provide?
- What is a sump receiver and why does it matter at drains?
Commercial Roof Replacement / Re-Roofing
