Roof Ballast Rock

The gravel top coat is also extremely resilient to heavy foot traffic and high wind scenarios.

Roof ballast rock. The stone ballast on a ballasted roof system is the only thing holding the roof system in place. There are no fasteners installed at all 3 and 4. 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. Single ply roofing materials aren t self adhered nor are they sealed together in any way.

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. A ballasted roof means that the roof membrane is not anchored or adhered in any way to the decking material. Next the membrane is rolled over the insulation 2. The buildup is ballasted with a gravel layer of at least 50 mm and 80 kg m 2.

In windy areas ballast stone can actually blow off the roof creating projectiles below. Despite the positive qualities associated with a ballasted roof system there are some challenges. The insulation is loose laid onto the decking. Gravel ballasted roofs with sikaplan or sarnafil single ply membranes are conventionally installed.

The single ply membrane and other roof components including thermal insulation are loose laid. Stone ballast is no longer allowed by many building codes. The ballast is used to keep the roofing system cool and of out of the sun s harmful rays thus keeping energy costs down.