Flat Roofs With Rocks On Top

If the roof is what is called a ballast roof it is not fastened or adhered down throughout the whole roof.

Flat roofs with rocks on top.

Modified bitumen built up roofing. Gravel is used on flat roofs for two reasons. Rocks are placed on commercial flat roofs for many different reasons. Though primarily confined to built up asphalt roofing systems it can be applied to single ply epdm rubber based membranes as well.

If there is a complete covering of the roof with small rocks gravel then it is the top layer of a built up flat roof this protects the other layers from damage by hail or storms also people. A built up roof bur sometimes called a tar and gravel. Types of gravel and tarred roofs there are two main types of burs or tar and gravel roofing systems modified bitumen roofs which are a mix of asphalt and rubber with a layer of gravel on top and ballast roofing which is a different style of larger gravel applied on top of a single ply roofing system. To weigh down or secure the roofing material as is the case with single ply flat roofs.

Plus it has the added advantage of reflecting heat from the sun which keeps energy costs down. Built up roofing bur was the most common type of flat roof before modified bitumen and membrane roofing were developed. Bur consists of many layers. The purpose of stone or gravel ballast on a flat roof it is not unusual to find a gravel top coat on commercial roofing systems.

There are different types and weights of gravel used on flat roofs for these purposes. A wear surface of finely crushed stone granules is usually applied to the top layer of hot tar to protect the built up roof assembly from uv light and weather. Once made of tar paper these types of roofs gradually are using more advanced materials such as fiberglass membranes. Built up roof bur the traditional hot tar and gravel roof is built from three or more plies of waterproof material alternated with hot tar and ballasted by a layer of smooth river stone.

Metal is one of the most popular materials used for flat roof replacement. Flat metal roofs can last for almost 35 years in ideal conditions. A bottom layer or two of insulation board multiple intermediate layers of tar or asphalt alternated with layers of roofing felt and a top layer of gravel.