Roof maintenance is one of the most neglected areas in the roofing industry. This is unfortunate, since it can be one of the biggest money savers for building owners and one of the most profitable areas for roofing contractors. And many times, when maintenance of roofs is contracted, it is not diligently performed.
Coatings & Roofing Sheets
Asphaltic coatings are the inexpensive traditional solution. They are composed of asphalt either in a cutback solvent or emulsified in water and work as a protective layer. However, asphalt is extremely susceptible to ultraviolet (UV) radiation and is not long-lasting. Aluminized asphalt coatings are a more costly solution. They maintain their popularity because of the reflectivity associated with them. These oil-based coatings impart a bright silver appearance. Usually within one year, however, the aluminum pigments oxidize and leave a dull gray color. This causes the coating to lose its reflective capabilities, which decreases the energy-saving benefits. The asphalt in these particular coatings makes them especially prone to UV degradation. Today, nonconventional, liquid-applied maintenance coatings are gaining acceptance because of their practicality. Aged modified-bitumen roofing (MBR) sheets can be used over traditional BUR systems, as well as over the new single-ply systems, MBR sheets, and polyurethane foam. These nonconventional synthetic coatings place virtually no extra weight on the roof deck or its supporting members. Even though they are initially more costly than their conventional counterparts, these newer coatings are more effective in the long run, primarily with ethylene propylene diene terpolymer (EPDM) or aged BUR and MBR, because they eliminate the need for radical re-roofing.
Roofs can be re-coated without adding significant weight to the roof load, and the coatings can be formulated in white to impart increased reflectivity to the roof. Besides contributing to longer service life by reflecting UV rays, the white color keeps the roof surface cooler, which reduces the demand for air conditioning inside the building. The advantages of longer service life and decreased energy costs are the driving forces behind the popularity of reflective roof coatings. The most distinguishing feature of liquid-applied roof coatings is that they are elastomeric, or flexible.