Flat Roof Stone Ballast

The purpose of stone or gravel ballast on a flat roof.

Flat roof stone ballast.

Next the membrane is rolled over the insulation 2. 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. A number of attachment and ballast options are available depending on the planned system and the conditions on site. The insulation is loose laid onto the decking.

Most ballast removal companies will come and get the job done right but that still requires you to find a qualified roofing expert to handle the repairs. I recently looked a leaky flat rubber mambrane roof having large river stone ballast. Though primarily confined to built up asphalt roofing systems it can be applied to single ply epdm rubber based membranes as well. Stone ballast is no longer allowed by many building codes.

Your flat roof requires repairs but it s covered in either gravel or ballast stones which makes it challenging to work on. Stones have been used as roofing ballast since antiquity and in its modern form stone ballast goes back to at least the 1970s. It s fire resistance ballast roofing offers class a fire resistance without the need for gypsum underlayments or expensive fire. The ballast is spread 2 4 in thickness acrossed the membrane.

It is not unusual to find a gravel top coat on commercial roofing systems. 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. If you ve ever seen a flat roof covered with gravel and wondered why the answer is simple it s there to keep the roof in place. 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. It can also be a bit challenging to find a leak with a ballasted roof system and because the stones tend to collect a lot of dirt patching it can be a bit difficult. Ballast stone can crush the underlying insulation creating weak spots in the roof membrane. Additional benefits of ballast on a flat roof.

Over time the stones move around creating bald spots where the system isn t held down at all. The gravel in a ballasted roof helps absorb heat preventing the sun from heating the roof materials below and making the roof more energy efficient. In windy areas ballast stone can actually blow off the roof creating projectiles below. Ballasted flat roofs are a popular choice especially for commercial buildings.

The easiest way to use flat roofs for photovoltaic systems. Published by justin on september 19 2019 september 19 2019.