Tar and gravel commercial roofing is technically known as BUR, “built up roof membranes”. This type of roof is used frequently for Woodridge IL commercial roofing; the system has been in continuous use for over 100 years.
This type of commercial roof is made up with alternating layers of bitumen and reinforcing material until the membrane is completed to specification. Typically these roofs are built to a certain “ply” thickness, four ply is common; the first ply is normally fastened to the structure supporting the roof.
The reinforcing material that is normally used is either sheets of plywood or roofing felt. Roofing felt are either organic in nature or they can be reinforced with fiberglass. Regardless of the way the felt is produced it is delivered to the job site on rolls.
The bitumen used for Woodridge IL commercial roofing is either asphalt or tar. The bitumen is heated on site in a large kettle and from there applied to the surface with a mop, roller or a mechanical spreader. Asphalt is petroleum based; it is refined from crude oil while coal tar is distilled from coal.
The top surface of a built up roof is an aggregate of some description, usually gravel, slag or mineral granules. As an alternate to aggregate, the top coating can be elastomeric or aluminum. A roofing system made which consists of three ply and modified polymer bitumen is described in the roofing community as a “hybrid.”
Modified polymer bitumen is a product that was first developed and used in Europe in the early 1960s, it rapidly found favor in the US and has been in constant use since the mid 1970s. This system consists of a reinforcing fabric that acts as a carrier for the hot bitumen which is factory applied; this product is also delivered to the job site in rolls. This particular type of roof is called MB, obviously for Modified Bitumen. An MB roof consists of multiple plies similar to a BUR system but is fully adhered upon installation.
Woodridge IL commercial roofing is available in two different MB types:
* SBS which is installed with hot application of asphalt or using a cold adhesive; some have adhesive back membranes which eliminates the need for hot asphalt or other adhesive methods.
* APP modified polymer membranes are welded or applied with an open flame. This type of membrane is rarely applied when the decking material is wood for obvious safety reasons.
APP modifiers give the finished roof a plastic quality whereas SBS have more of rubber quality asphalt. Another type of membrane that is often confused with MB is a thermo set membrane called EPDM, this type of roofing is normally called “rubber roofing”.
Woodridge IL commercial roofing can be supplied and installed by the professionals at Showalter Roofing Services, Inc. Click here to know more.
