About Ballasted Roof Systems
A ballasted roof system is a specific type of single-ply commercial roofing installation where the membrane (often EPDM) is not mechanically attached or adhered to the roof deck with fasteners or glue. Instead, it is securely held in place by the sheer weight of a ballast, typically consisting of smooth river rock, washed gravel, or concrete pavers. This system is highly cost-effective, relatively fast to install in various weather conditions, and provides excellent Class A fire resistance and superior protection against UV degradation. It is commonly used on large, structurally sound flat commercial buildings.
Frequently Asked Questions
What are the primary advantages of a commercial ballasted roof?
They are very economical, fast to install year-round, and the heavy ballast provides excellent, long-lasting protection for the underlying waterproofing membrane.
Can a ballasted roof system handle high wind uplift?
Yes, but the size, gradation, and weight of the stone or paver ballast must be properly engineered and distributed based on the building height and local wind zone conditions.
Are ballasted roofs too heavy for standard buildings?
Yes, they add significant dead load; the building’s structural deck must be specifically designed and engineered to support the heavy weight of the stone or paver ballast.
How is leak maintenance performed on a ballasted roof?
Maintenance can be more challenging and labor-intensive, as the heavy ballast must be carefully moved aside to inspect, locate, or repair the underlying membrane.
