Built up roofing or tar roofing, is the oldest and least seldom used type of commercial flat roofing anymore by contractors. In this system, a base sheet is applied to the deck, and then hot asphalt is “mopped” over it. Typically 2-3 more layers of the felt are added with an additional layer of hot asphalt coated over top. Afterwards, a layer of small gravel is embedded into the asphalt which gives the roof a more finished look and also aids in ultra violet protection.
Another type of flat roof system is the APP or torch down system. This is also known as a method to create rubber roofs. APP (Atactic Polypropylene) is a strong, resilient, non-woven polyester mat that is coated with a special type of modified asphalt. A torch-down flat roof is easy to repair and needs little maintenance. It’s also flexible, because of the blend of asphalt with synthetic rubberized polymers. This means a torch down application is more adaptable to extreme changes of weather and other climate changes.
Over the last 2 decades, single ply roof systems have taken a much larger share of the commercial roofing market. As new regulations are passed each year, the roofing industry is moving towards products that do not contain asphalt and have a white surface color. The 3 most common types of single ply membranes are EPDM (ethylene propylene diene monomer), TPO (thermo plastic olefin), and PVC (poly vinyl chloride). Although the chemical compositions are different, their methods of installation are very similar. They offer a 15-25 year warranty and are sometimes more preferred since they come in larger rolls which means less seams needing sealing or flashing.
More recently, a self-adhered or peel and stick roll has been introduced. With this system, the flat roofing contractors kick the roll out and peel off the release paper. Once the paper is off, the exposed membrane will adhere to either a base sheet or roof deck. These systems eliminate many of the disadvantages of the other systems, but are more expensive. Also, the window of opportunity for doing this work is much smaller as it is very sensitive to outside temperatures.
Lastly, coatings are especially useful for re-roofing, renovations, and recover applications. The two basic types are a roll on coating, or a spray on that requires special equipment. Rather than trying to manipulate larger cumbersome materials (often requiring cranes) these product are more portable, and easier to apply. For property owners who have rounded buildings, a small area to cover, or existing roofing they want to extend the life of, this type of repair can be a viable solution.
For more information or to schedule a free estimate, please contact one of our knowledgeable sales representatives today.