Rock Ballast Roof

A ballasted roof means that the roof membrane is not anchored or adhered in any way to the decking material.

Rock ballast roof.

Request a sample for the most accurate color representation. A complete line of custom prefabricated accessories is available for the designer series membranes. It is however ballasted generally with gravel. Ballast is required with 20 lbs s f.

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. Conventional gravel ballasted roofs have been built for many years and are suitable on most flat roofs and structures. 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. Over time the stones move around creating bald spots where the system isn t held down at all.

A1 grit ballast is a natural smooth water worn and screened large gravel used for many applications. Stone ballast typically requires crushed graded stone placed over a stone filter sheet rolled out over the insulation. Our roofing ballast is commonly installed over membrane and single ply systems at 1000 1500 pounds per square. Despite the positive qualities associated with a ballasted roof system there are some challenges.

Roof perimeters and penetrations are flashed in accordance with firestone specifications pdf. Needed at perimeters and at large penetrations. When the concept first came to the u s plenty of roofers scratched their heads and wondered how the roof stayed on without being anchored especially during high winds or storms. Gravel in form of round smooth river washed aggregate without broken pieces nominal 16 to 32 mm.

The gravel top coat is also extremely resilient to heavy foot traffic and high wind scenarios. The shingle ply membrane is printed with a shingle design in sandstone tan or slate gray. Ballast stone can crush the underlying insulation creating weak spots in the roof membrane. In gravel ballasted roofing systems the waterproofing membrane is covered and ballasted against wind uplift and other exposures with a layer of gravel.

In windy areas ballast stone can actually blow off the roof creating projectiles below. The rock ply membrane is printed with the appearance of a ballast roof. Single ply roofing materials aren t self adhered nor are they sealed together in any way. Contact hydrotech for specific installation guidelines.

Stone ballast is no longer allowed by many building codes.