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Johnston Roofing

Johnston Roofing is a family-owned and operated business which specializes in cold-process roofing systems. Their reputation has spread well beyond the confines of their headquarters in Martinez, CA.
Indeed, even the owners of the Louisiana Superdome have turned to Johnston Roofing when the roof of that famous building began to leak.

Although the term applies to a number of different applications, cold process roofing gets its name from the simple fact that hot asphalt is not utilized. In full-blown re-roofing and roof maintenance applications, “cold” asphalt emulsions or adhesives are spray-applied between polyester mats or fiberglass base sheets. Asphalt emulsions reinforced with glass fibers are then sprayed over them to form a seamless monolithic roof membrane. These applications are “cold” alternatives to traditional “hot” built-up roofing.

Cold-applied roofing systems are very forgiving. The adhesives used by Johnston Roofing set slowly, allowing fiberglass plies to be easily reset, if necessary. Similarly, the asphalt emulsions we apply are permeable to water vapor, so moisture trapped underneath a cold-applied membrane can escape without damaging it. And because of their exceptional pliability, cracks and “alligators” are rarely seen in cold process roofs.

A very successful part of Johnston Roofing’s business has been applying cold-process maintenance systems over existing cap sheet roofs. Where a cap sheet roof is near the end of its service life, but not so badly deteriorated that it needs to be removed and replaced, a system consisting of two layers of polyester matting embedded in asphalt emulsion and finished with chopped fiberglass and emulsion along with a reflective aluminum coating can be applied. These systems can extend a roof’s life significantly at relatively low cost.

Cold-applied coatings are also an integral part of many other types of roofing systems, providing a necessary or desirable “finishing touch” to the roof. Manufacturers of modified bitumen membranes frequently recommend the application of a topcoat to protect the roofing system from ultraviolet radiation and other environmental influences which are harmful to asphalt membranes. In some cases, such a coating must be applied in order for the roof assembly to achieve a Class ‘A’ fire rating.

Reflective coatings are commonly applied to improve the performance of a variety of roofing systems. A well-insulated building is cost-effective from a heating and cooling perspective, but may also subject the roof to severe temperature cycles which promote membrane splitting and cracking. Reflective coatings can dramatically reduce these stresses and thereby extend the service life of the roof. They have also been shown to reduce air conditioning costs.

Coatings can also enhance the appearance of a roof. In recent years, a wide variety of colored and textured coatings have become available to broaden consumer options beyond the traditional choices. Wherever a roof is visible to neighbors or passersby, a colored roof coating can be employed to enhance its visual appeal.

From a business management standpoint, one of the things we like most about cold-process roofing is that you don’t have to be “big” to do it. Compared to other types of roofing, it is not terribly labor-intensive. This means that Johnston Roofing can operate very successfully while maintaining a small crew and a “family” atmosphere.

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