Ask any roofer in Houston and they would say a cool roofing system is one that strongly reflects sunlight and also cools itself by efficiently emitting radiation to its surroundings.
The roof literally stays cooler and reduces the amount of heat conducted to the building below. If a builder does not have air conditioning, this keeps the building cooler and a more constant temperature. If a building has air conditioning, the equipment does not have to work as hard. Imagine wearing a white or a black T-shirt on a hot day. By wearing the white T-shirt you will remain cooler than if you wore a black T-shirt because it reflects more sunlight and absorbs less heat. Cool roofs, like a white T-shirt, keep the internal temperature of the building lower.
TPO Roofing is composed of thermoplastic membrane similar to synthetic rubber, but the seams are typically heat-fused (welded) to form a continuous membrane. The 'lap' seams can also be fused with solvents instead of heat, and can be as strong as the rest of the membrane. Other related materials are CPA, CPE, EIP, NBP, PIB, and TPO. Thermoplastic membranes include a reinforcement layer that provides more strength and stability. The most common thermoplastic membranes are PVC (polyvinyl chloride) and TPO (thermoplastic polyolefin).
Bitumen is a term applied to both coal tar pitch and asphalt products. Asphalt alternative roofing services were not standard in Houston or any other place in the world until the latter half of the 20th century. Modified Bitumens were developed in Europe in the 1970s when Europeans became concerned with the lower performance standards of roofing asphalt. Modifiers were added to replace the plasticizers that had been removed by advanced methods in the distillation process. The two most common modifiers are APP (atactic polypropylene) from Italy and SBS (styrene-butadiene-styrene) from France. The United States started developing modified bitumen compounds in the late 1970s and early 1980s which led to modified bitumen roofing services becoming standard practice in Houston.
A flat roof is a roof which is almost level in contrast to the many types of sloped roofs. The slope of a roof is properly known as its pitch and flat roofs have up to approximately 10°. Flat roofs are an ancient form mostly used in arid climates and allow the roof space to be used as a living space or a living roof. Flat roofs, or "low-slope" roofs, are also commonly installed and repaired on commercial buildings in Houston.
