Stone Ballast Roof

This again is loose so there are no fasteners or glues used to hold it down.

Stone ballast roof.

Over time the stones move around creating bald spots where the system isn t held down at all. Firestone epdm ballasted system application. These small stones. Though primarily confined to built up asphalt roofing systems it can be applied to single ply epdm rubber based membranes as well.

Large mixed color decorative rock. 2 1 2 8 unwashed rock. Additional benefits of ballast on a flat roof. Unwashed landscaping decorative drainage and roof ballast stone.

Stone ballast is no longer allowed by many building codes. Ballast is required with 20 lbs s f. There are no fasteners installed at all 3 and 4. In windy areas ballast stone can actually blow off the roof creating projectiles below.

White ballast can range in size from 2 1 2 3 4 inches and can be made to meet various astm standards. Stone ballast typically requires crushed graded stone placed over a stone filter sheet rolled out over the insulation. Ballasted flat roofs are a popular choice especially for commercial buildings. In the field of the roof a minimum of 10 lbs s f.

The amount of ballast varies from 50 to 65 kg m 10 to 13 psf in conventionally loose laid gravel stone ballasted single ply assemblies. The stone ballast on a ballasted roof system is the only thing holding the roof system in place. It is not unusual to find a gravel top coat on commercial roofing systems. The weight on a ballasted roof can be from 10 to 25 pounds per square foot meaning the substructure must be designed specifically to carry more weight than other roofing systems.

It can also be a bit challenging to find a leak with a ballasted roof system and because the stones tend to collect a lot of dirt patching it can be a bit difficult. White ballast a1 grit ballast is a natural smooth water worn and screened large gravel used for many applications. The firestone epdm ballasted system is an economical epdm roofing system suitable for a wide variety of buildings it can be applied on any building that can accommodate the extra load of the ballast and where the roof slope does not exceed 10. Next the membrane is rolled over the insulation 2.

Ballast stone can crush the underlying insulation creating weak spots in the roof membrane. Published by justin on september 19 2019 september 19 2019. Needed at perimeters and at large penetrations. The gravel in a ballasted roof helps absorb heat preventing the sun from heating the roof materials below and making the roof more energy efficient.

Ballast is assumed to be round 38 mm 1 5 in or 64 mm 2 4 in smooth stone consisting of ballast gradation sizes 2 and 4 as specified in american society for testing and materials astm d448. Our roofing ballast is commonly installed over membrane and single ply systems at 1000 1500 pounds per square. Medium mixed color decorative rock.