Stone Ballast Roof

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.

Stone ballast roof.

Additional benefits of ballast on a flat roof. Stone ballast is no longer allowed by many building codes. These small stones. 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.

Ballasted flat roofs are a popular choice especially for commercial buildings. 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. White ballast a1 grit ballast is a natural smooth water worn and screened large gravel used for many applications. There are no fasteners installed at all 3 and 4.

In windy areas ballast stone can actually blow off the roof creating projectiles below. Ballast is required with 20 lbs s f. The insulation is loose laid onto the decking. Large mixed color decorative rock.

Medium mixed color decorative rock. The purpose of stone or gravel ballast on a flat roof. Ballast stone can crush the underlying insulation creating weak spots in the roof membrane. Next the membrane is rolled over the insulation 2.

In the field of the roof a minimum of 10 lbs s f. White ballast can range in size from 2 1 2 3 4 inches and can be made to meet various astm standards. Unwashed landscaping decorative drainage and roof ballast stone. 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.

Stone ballast typically requires crushed graded stone placed over a stone filter sheet rolled out over the insulation. 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. Published by justin on september 19 2019 september 19 2019.

The stone ballast on a ballasted roof system is the only thing holding the roof system in place. 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 is not unusual to find a gravel top coat on commercial roofing systems. 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.

Though primarily confined to built up asphalt roofing systems it can be applied to single ply epdm rubber based membranes as well. This again is loose so there are no fasteners or glues used to hold it down. Over time the stones move around creating bald spots where the system isn t held down at all.