Stone Ballast Roof

The purpose of stone or gravel ballast on a flat roof.

Stone ballast roof.

Additional benefits of ballast on a flat roof. 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 stone can crush the underlying insulation creating weak spots in the roof membrane. The insulation is loose laid onto the decking.

In windy areas ballast stone can actually blow off the roof creating projectiles below. Over time the stones move around creating bald spots where the system isn t held down at all. 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. Stone ballast typically requires crushed graded stone placed over a stone filter sheet rolled out over the insulation.

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. Medium mixed color decorative rock. 2 1 2 8 unwashed rock. 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.

Ballast is required with 20 lbs s f. The stone ballast on a ballasted roof system is the only thing holding the roof system in place. In the field of the roof a minimum of 10 lbs s f. Ballasted flat roofs are a popular choice especially for commercial buildings.

Needed at perimeters and at large penetrations. 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. Firestone epdm ballasted system application. Next the membrane is rolled over the insulation 2.

There are no fasteners installed at all 3 and 4. 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. White ballast can range in size from 2 1 2 3 4 inches and can be made to meet various astm standards. Click here to edit text 2 round blue gravel approx 1 1 2 3 excavated from our pond with a natural blue tint with brown and natural color hues.

Unwashed landscaping decorative drainage and roof ballast stone. White ballast a1 grit ballast is a natural smooth water worn and screened large gravel used for many applications. These small stones. Large mixed color decorative rock.

It is not unusual to find a gravel top coat on commercial roofing systems. Stone ballast is no longer allowed by many building codes. Published by justin on september 19 2019 september 19 2019.