Roof Ballast

Definition

Roof ballast is crushed rock or gravel spread on a roof surface to form its final surface.

Purpose

The purpose of roof ballast is to weigh down the roofing membrane, protecting it from wind uplift and mechanical damage while providing a durable and aesthetically pleasing surface.

Examples of Use

• Flat or low-slope commercial roofs often use gravel as ballast to secure the roofing membrane.
• Green roofs incorporate ballast materials to support vegetation and manage stormwater.
• Industrial buildings use ballast to protect roofing systems and extend their lifespan.

Related Terms

• Roofing Membrane: A continuous layer used to waterproof a roof.
• Built-Up Roof: A roofing system made of multiple layers of roofing felt and bitumen.
• Green Roof: A roof covered with vegetation to provide environmental benefits.

Notes

Roof ballast must be evenly distributed and appropriately sized to ensure it effectively secures the roofing membrane and provides adequate protection.