Gravel Ballast Roof Weight

The use of timber decking can also be considered as a ballasted application but due to its general lack of sufficient actual dead weight to resist.

Gravel ballast roof weight.

I ve had the same questions i think that the 6 psf range given in many tables is for a multi ply roofing with gravel that is impregnated into the top layer. The single ply membrane and other roof components including thermal insulation are loose laid. The stones used in ballasted roofing are generally 1 5 2 5 inches in diameter and applied in a thicker layer. When it comes to estimating the weight of an existing roof field verification of the in place construction is necessary.

Adds a lot of weight to the roof system typically 10 15 pounds per square feet. Ballast tar gravel roofing. Roofs with pavers as ballast can be used as outdoor patios. Gravel ballast of 20 40 mm diameter is required in order to provide resistance to the effects of wind scour bre digest 311 july 1988 refers which can easily remove smaller units from the roof.

The gravel can be applied in far less time than using a specially designed screw and plate fastening pattern. None asphalt roll roofing. Extremely difficult to find a leak in this system since the membrane is well hidden. Gravel on a ballast roof system.

Check out eng tips forum s policies here. Drawbacks of a ballasted roof system. Ballast is a different style of gravel which is applied to single ply roofing systems. Specifically there are two main reasons to use a ballasted roof system.

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. Ballast stone traps a lot of dirt making patching difficult. A loose ballasted roof where you have 1 to 2 inches of gravel is more on the order of 12 psf. Although the primary purpose of ballast is to weigh down the roofing materials it also offers similar protective benefits as described above.

Gravel ballasted roofs with sikaplan or sarnafil single ply membranes are conventionally installed. The weight of roofing constructions above the truss rafter may be estimated with the calculator below. Felt tar and gravel roofing 4 ply 5 3 lb m ft 2 25 9 kg m 2 felt tar and gravel roofing 5 ply 6 1 lb m ft 2 29 8 kg m 2. 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.

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.