When covering a roof with a flat surface or a low pitch, many Houston businesses and facility owners use a technique known as "building up" the roof. This means that a Houston roofing team will start at the foundation, next to the structure of the roof, and apply layer after layer of impermeable material until a weatherproof seal is created. This type of roofing is known to be inexpensive and not terribly durable. Some types of built up roofing may last for as long as 25 years.
While there are many different types of built up roofing, or BUR, they all work on the same principle. To begin with, a waterproof sheeting will be placed on the bottom. In the past, tar paper was used, but now membranes incorporating bitumen, plastic and fiberglass are more convenient for this purpose. In addition to water resistance, sheeting provides insulation, fire resistance and strength. The bottom layer is usually fastened to the roof, but the weight of the layers on top of it are often enough to hold it in place without further effort.
After that, it is simply a matter of adding layer after layer.
Roofers from Houston Restoration Services of Houston TX would be happy to answer any question you have about remodeling or storm damage.
These layers, or plies, can be built up to whatever thickness is desired, and the material can be made of whatever is appropriate to that application. For example, a glass fiber or organic mat can be applied for greater insulation. After the desired level of protection is achieved, a heavy application of asphalt is spread or poured onto the roof to cover it to an even thickness across the entire surface. The hot tar is then coated with gravel. This gravel provides a surface for workers to stand on without damaging the roof or their equipment, and the light color of the pebbles reflects much of the sun's heat away from the building.
Unfortunately, due to the nature of flat roofing, a drawback associated with "building up" a roof is the presence of leaks that may be hard to locate. Water has the ability to penetrate one layer of the roof, travel a substantial distance and then enter through the ceiling below in an entirely different spot. The only way to trace the leak to its source is to pull up roofing material. In these situations, it is common to simply pour or place another layer of roofing above the ones that exist. This process may be continued indefinitely, so long as the structure of the building can support the weight of another layer of roofing.