Ballasted commercial roofs have been around for decades, and there are many reasons why. Ballast – and the waterproof membrane it holds in place beneath – can handle building movement well. Ballast, which is a natural material, aesthetically complements different architectural characteristics. Stone ballast is essentially fireproof, and ballasted roofs provide high fire ratings. Ballast also helps protect the membrane from UV rays and hail.
But there are also some drawbacks to ballasted commercial roofs, including:
First, ballast makes it impossible to simply examine the roof’s waterproof membrane visually or with a drone mounted camera. Since visual inspection is the primary method used for catching the early signs of leaks and other serious forms of roof damage, a roof with ballast on it is obviously an impediment. Ballast must be moved each time you want to inspect the underlying membrane to locate a problem area and relocating stones on the rooftop invites membrane damage. A commercial roof system without ballast makes for easier troubleshooting.
Ballast Stones Move
Over time, wind and traffic tend to move the stones around, creating bald spots where the roof membrane isn’t held down well, and that area could become susceptible to wind uplift, potentially creating stress on seams and other problems. Also, in windy areas, ballast stones may get blown off the roof, which can be dangerous to people on the ground. Ballasted roofs need to be checked after wind events and the stone needs to be re-set if material is missing.
Most flat roofs experience foot traffic, and that can lead to punctures with a ballasted roof. Holes create roof leaks which (as discussed above) are problematic to find and repair. Also, over time, from being walked on and weathering, stones can fracture and break apart, creating sharp, jagged edges. These edges make it more likely that the roof membrane will be cut the next time it’s stepped on.
If you’re tired of dealing with ballasted roof hassles, give Royalty a call. We’ll remove the ballast and install and nice, clean single-ply roofing system that will provide watertight protection for years to come.