Stone Ballast Roof Weight

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.

Stone ballast roof weight.

Ballast stone traps a lot of dirt making patching difficult. This study was presented to epa and a submittal was made to have this cool ballasted system listed as a qualified energy star roof product. Ballast is different from bur protective gravel. Ballast stone fractures and gets sharper over time which can puncture the.

Despite the positive qualities associated with a ballasted roof system there are some challenges. Extremely difficult to find a leak in this system since the membrane is well hidden. Adds a lot of weight to the roof system typically 10 15 pounds per square feet. 52 5 97 65 kg.

Epdm roof membrane 60 mil ballasted membrane and stone ballast only 10 75 20 lbs. The weight of roofing constructions above the truss rafter may be estimated with the calculator below. Since nothing secures the waterproofing membrane to the roofing materials underneath ballast is needed for weight to protect the roof from strong winds. Too much gravel can result in a structural issue due to weight.

Epdm roof membrane 60 mil fully adhered membrane only 0 47 lbs. A ballasted roof generally refers to a single ply roof membrane that is held in place against wind uplift by loading the surface with either stone ballast or pavers. Drawbacks of a ballasted roof system. It is very important to note that the amount of gravel being applied to a roof must be precise it depends on the specific roofing spec being used and the building type.

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. Ballast stones are usually one to two inches thick and applied more generously than on a built up roof. 1075 2000 lbs. This study showed that when the ballast weight is a minimum of 15 psf or greater the ballasted system stone or paver performs the same or better than the energy star listed tpo product.

None asphalt roll roofing 1 1 lb m ft 2 5 4 kg m 2 asphalt shingle or asphalt fiberglass composite shingle 2 7 lb m ft 2 13 2 kg m 2. This study showed that when the ballast weight is a minimum of 15 psf or greater the ballasted system stone or paver performs the same or better than the energy star listed tpo product. 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. Since the ballast is the primary.

The membrane for such systems is usually not attached to the substrate although some systems do have supplementary perimeter attachment.