Modified Bitumen systems consist of asphalt with added modifiers for durability. These are either one- two- or three ply-systems, with two-ply being the most common. They are factory manufactured and combine the redundancy of built up roofing with the ease of application of a single-ply system.
Both SBS and APP systems can be reinforced with glass or polyester.
Advantages of a Modified Bitumen sytem include:
A built-up roof consists of plies of reinforcing material (organic felts, fiberglass mats or polyester), inter-ply layers of bitumen (asphalt or coal tar) and a finish surfacing, such as gravel or decorative rock, mineral surface cap sheets, or coatings. Owing to energy concerns, many built-up systems today incorporate rigid board insulation as well. Built-up roofing is one of the oldest and most durable systems available. Introduced during the 1840s, built-up ("tar and gravel") roofing remains the predominant system installed on low-slope ("flat") roofs. They are ideally suited for applications requiring a high level of redundancy.
Built-up Roofing System advantages:
The repetitiveness of a built-up roofing system -- its layer upon layer nature -- provides both flexibility and durability. The number of plies and the materials used for surfacing can be varied to adapt the system to virtually any environmental or aesthetic concerns. For the same reason, a built-up roof is more forgiving of abuse after application than are many other roofing systems.
Single-Ply roofing systems are composed of insulation, a single ply membrane, flashings, and adhesive. Single-Ply is lightweight, consisting of a single layer of roofing over insulation. This makes them a great choice for retrofits. TPO, EPDM, and PVC are the three most common types of single-ply membrane systems.
ThermoPlastic Olefin (TPO) advantages include:
Ethlyene Propylene Diene Terpolymer (EPDM) advantages include:
Polyvinyl Chloride (PVC) advantages include:
There are three general types of Metal roof system applications:
Metal roofing is a preferred alternative for sloped roofs, especially when durability and weather resistance are major concerns. The different systems are engineered not only to accommodate the slope of a structure's roof, but to provide pleasing aesthetics, since these roofs are often visible from the street level.
Architectural Sheet Metal is a specialized type of metal roofing, usually involving steep slopes. These roofs feature custom fabricated sheet metal flashing and trim and are often used for historic, retrofit projects. We use various gauge metals and various metal types, from pre-finished galvanized steel and aluminum to copper, stainless steel, lead and coated copper.