There are a lot of different types of residential roofing material available for residential units
. Some are more common than others and some are cheaper than others. Some work better on different types of roof shapes than others do.
A common roof type is the flat roof. These will generally be in an area that has little or no snowfall because the roof would hold all the snow and might collapse under the weight of it. This type of roof has a couple of residential roofing materials. One of them is called a tar and gravel roof. There will not be any shingles on this type of roof because shingles are not a good choice for a flat roof as they just lie there in layers waiting for rain to pond on them.
Basically a flat roofing material is a base material with some coating on it. A tar and gravel roof will have layers of asphalt and tar paper that are attached to the roof with a hot asphalt application. They are covered with gravel to hold them down and prevent penetration from the suns UV rays.
There are other forms of flat roof applications that may be made from PVC or other plastic forms. They may also be modified bitumen. This is a roof covering composed of a factory fabricated sheet with copolymer- modified bitumen. And bitumen is a mixture of hydrocarbons and others that are natural or derived from coal or petroleum and are a component of asphalt and tar.
Flat roofs generally have a rolled covering where the integrity of it depends on the application by the installer. The seams of the roofing material rolls are attached or overlaid with different types of applications to hold it together.
A green roof is also a possibility for a flat roof. But before this type of roof is installed you have to insure the structure of the building can hold its weight. This is basically a roof covered with a protective covering, a planting medium and then vegetation.
Flat roofs have the best chance for leaking because there are often low spots and the water ponds on these low spots and sits. As the water sits on the roof it sinks in and causes leaks. The same happens when gravel blows off exposing the base material to the elements.
There are several residential roofing choices available for a flat roof.