Gravel Ballasted Roofs

Too much gravel can result in a structural issue due to weight.

Gravel ballasted roofs.

Despite the positive qualities associated with a ballasted roof system there are some challenges. Holes mean roof leaks and roof leaks mean call the roofer. The stones used in ballasted roofing are generally 1 5 2 5 inches in diameter and applied in a thicker layer. Most ballasted roof systems use gravel stone that is similar to what would be used in landscaping.

A built up roof for example will typically include the built up membrane itself with or without gravel as well as some kind of insulation and cover board which will vary in thickness from roof to roof. For built up roofing the gravel was generally 25 5 inches in diameter. On the other hand ballast roofing might be the right choice for your commercial property if you live somewhere with a ready source of ballast rocks gravel of the appropriate size and you prefer the aesthetic look and texture of the larger stones. Gravel in form of round smooth river washed aggregate without broken pieces nominal 16 to 32 mm.

Ballasted roof systems have been installed since the early 1970 s. Roof perimeters and penetrations are flashed in accordance with firestone specifications pdf. Simply put a ballasted roof is easy to install and basically guaranteed maintenance work for a roofer. However other ballasted systems use pavers which are easier to walk on and can be.

Ballast tar gravel roofing. The buildup is ballasted with a gravel layer of at least 50 mm and 80 kg m 2. Ballasted roof systems are simultaneously a roofer s best friend and arch nemesis. 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.

The gravel used in built up roofing what the roofing contractors were used to was not the same as that used in a ballasted roof. They are known for their installation speed and pleasing aesthetics. Gravel ballasted roofs with sikaplan or sarnafil single ply membranes are conventionally installed. It is very important to note that the amount of gravel being applied to a roof must be precise it depends on the specific roofing spec being used and the building type.

When it comes to estimating the weight of an existing roof field verification of the in place construction is necessary. 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. The single ply membrane and other roof components including thermal insulation are loose laid.