What Is a Ballasted Roof?
Ballast is the paperweight of roofing. Most commonly used with EPDM roofing, ballast typically comprises stone, gravel or pavers that are placed on a loose-laid membraneMaterial - A single-ply membrane is a roof covering that uses one continuous layer of material to waterproof low-slope roofs. More to secure it against wind upliftPerformance - Wind uplift is the upward force exerted on a roof system when wind over a building creates suction and pulls against the roof assembly. More.
Starting in the 1980s, many large commercial low-slope roofsRoof Types - Low-slope roofs (flat roofs) are a type of roof system with less than a 3:12 pitch, most commonly found on commercial and industrial buildings. More used ballast due to its cost-effectiveness and the additional protection from hail and UV it provided for the membrane below.
Because the membrane sits beneath the ballast, locating leaks and accessing the roof surface often requires sections of stone or pavers to be moved before the leak can be diagnosed or repairs can be made.