Asphalt composition roof covering.
Asphalt is the most commonly used roofing material. Asphalt products include shingles, roll-roofing, built-up roofing, and modified bitumen membranes.
Asphalt shingles are typically the most common and economical choice for residential roofing. They come in a variety of colors, shapes, and textures. There are four different types: strip, laminated, interlocking, and large individual shingles. Laminated shingles consist of more than one layer of tabs to provide extra thickness. Interlocking shingles are used to provide greater wind resistance. And large individual shingles generally come in rectangular and hexagonal shapes.
Roll-roofing products are generally used in residential applications, mostly for underlayments and flashings. They come in four different types of material: smooth-surfaced, saturated felt, specialty-eaves flashings, and mineral-surfaced. Only mineral-surfaced is used alone as a primary roof covering for small buildings like sheds. Smooth-surfaced products are used primarily as flashing to seal the roof at intersections and protrusions, and for providing extra deck protection at the roof's eaves and valleys. Saturated felt is used as an underlayment between the roof deck and the roofing material. Specialty-eaves flashings are typically used in climates where ice dams and water backups are common.
Built-up roofing (or BUR) is the most popular choice of roofing used on commercial, industrial and institutional buildings. BUR is used on flat or low-sloped roofs and consists of multiple layers of bitumen and ply sheets. Components of a BUR system include the roof deck, a vapor retarder, insulation, membrane and surfacing material.
Modified bitumen membranes
A modified bitumen membrane assembly consists of continuous plies of saturated felts, coated felts, fabrics or mats between which alternate layers of bitumen are applied, either surfaced or unsurfaced. Factory surfacing, if applied, includes mineral granules, slag, aluminum or copper. The bitumen determines the membrane's physical characteristics and provides primary waterproofing protection, while the reinforcement adds strength, puncture resistance and overall system integrity.