Rock Ballast Roof

In windy areas ballast stone can actually blow off the roof creating projectiles below.

Rock ballast roof.

A complete line of custom prefabricated accessories is available for the designer series membranes. Needed at perimeters and at large penetrations. Over time the stones move around creating bald spots where the system isn t held down at all. 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 stone can crush the underlying insulation creating weak spots in the roof membrane. 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. The gravel top coat is also extremely resilient to heavy foot traffic and high wind scenarios. Conventional gravel ballasted roofs have been built for many years and are suitable on most flat roofs and structures.

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. In gravel ballasted roofing systems the waterproofing membrane is covered and ballasted against wind uplift and other exposures with a layer of gravel. A1 grit ballast is a natural smooth water worn and screened large gravel used for many applications. A ballasted roof means that the roof membrane is not anchored or adhered in any way to the decking material.

Contact hydrotech for specific installation guidelines. Despite the positive qualities associated with a ballasted roof system there are some challenges. Ballast is required with 20 lbs s f. Stone ballast is no longer allowed by many building codes.

It is however ballasted generally with gravel. The ballast is used to keep the roofing system cool and of out of the sun s harmful rays thus keeping energy costs down. 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.

The shingle ply membrane is printed with a shingle design in sandstone tan or slate gray. Roof perimeters and penetrations are flashed in accordance with firestone specifications pdf. Single ply roofing materials aren t self adhered nor are they sealed together in any way. In the field of the roof a minimum of 10 lbs s f.

Gravel in form of round smooth river washed aggregate without broken pieces nominal 16 to 32 mm.