Rock Ballast Roof

Conventional gravel ballasted roofs have been built for many years and are suitable on most flat roofs and structures.

Rock ballast roof.

The ballast is used to keep the roofing system cool and of out of the sun s harmful rays thus keeping energy costs down. Gravel in form of round smooth river washed aggregate without broken pieces nominal 16 to 32 mm. In gravel ballasted roofing systems the waterproofing membrane is covered and ballasted against wind uplift and other exposures with a layer of gravel. In the field of the roof a minimum of 10 lbs s f.

Stone ballast is no longer allowed by many building codes. The gravel top coat is also extremely resilient to heavy foot traffic and high wind scenarios. 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.

Despite the positive qualities associated with a ballasted roof system there are some challenges. Needed at perimeters and at large penetrations. Once completed the epdm membrane is held in place using one of the following materials as ballast with a minimum weight of 50 kg m. Ballast is required with 20 lbs s f.

A ballasted roof means that the roof membrane is not anchored or adhered in any way to the decking material. It is however ballasted generally with gravel. Request a sample for the most accurate color representation. White ballast can range in size from 2 1 2 3 4 inches and can be made to meet various astm standards.

A1 grit ballast is a natural smooth water worn and screened large gravel used for many applications. Our roofing ballast is commonly installed over membrane and single ply systems at 1000 1500 pounds per square. Single ply roofing materials aren t self adhered nor are they sealed together in any way. Roof perimeters and penetrations are flashed in accordance with firestone specifications pdf.

Ballast stone can crush the underlying insulation creating weak spots in the roof membrane. The shingle ply membrane is printed with a shingle design in sandstone tan or slate gray. The rock ply membrane is printed with the appearance of a ballast roof. Ballast is commonly used with roofs made of tar and gravel roof alternatives including ethylene propylene diene monomer epdm polyvinyl chloride pvc and thermoplastic polyolefin tpo single ply flat roofs.

Contact hydrotech for specific installation guidelines.