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| Built-Up Systems |
| Written by Administrator | |
| Thursday, 08 February 2007 18:00 | |
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Multiple plies lend redundancy factor to BUR.
Through the years, Lakewood Roofing has become one of the most highly experienced Built-Up Roofing (BUR) contractors in Wisconsin and Michigan's Upper Peninsula. Lakewood Roofing has attained high regard in the commercial and industrial roofing industry with the installation of millions of square feet of sucessful BUR through the years, and with respect to expertise and efficiency Lakewood is second to none.
In recent history, Lakewood has become a National leader in the installation of innovative Cold-Process Built-Up in a variety of design schemes tailored to suit each individual application. With a myriad of design possibilities, Hot BUR and Cold-Process BUR exhibit characteristics which make these systems the greatest value for long-term applications. Built-Up roofing systems have been in use for well over 100 years, and over the course of time have yielded long-term performance without rival by any other type of roofing system. Built up roofing originally consisted of multiple layers of coal tar interspersed with layers of fabric reinforcement, or "felt" used to hold together the waterproofing tar. In recent times, bitumen has replaced coal-tar as the adhesive/waterproofing material of choice, and the original rag felts have been replaced by fiberglass reinforced rolls. Bitumen has been further augmented by modern chemistry with the addition of plastic polymers to the bitumen matrix in the pursuit of increased favoribility of physical characteristics. These characteristics include UV stability, tensile strength, and elongation capability.
Cold process capsheet application.
There are factors associated with BUR systems over the years which have remained quite constant, making these systems the roof of choice for building owners, architects, and quality roofing professionals. Redundancy of plies enables long service life with low maintenance costs, and a very low cost per year average when compared to any other low-slope system. The robust nature of ply redundancy also lends itself to favorable outcomes with regard to wind-uplift ratings, fire-resistance, and the actuarial peace of mind of a PROVEN system.
The two main types of Built-Up membrane differ in the material used to laminate the roofing plies or "felts" together to produce the final system. Hot Built-Up roofing relies on asphaltic bitumen heated to a nominal equiviscous temperature of 400 degrees farenheit mopped to the roofing surface to adhere subsequently applied plies. Cold process built-up relies on solvent-modified asphaltic adhesives which are viscous at ambient temperature for the bonding of felts in the roof system membrane.
Gravel surfacing used in some applications.
While Hot Built Up has traditionally enjoyed a larger share of the roofing market, cold process technology is increasing in prevalence due to many advantages and benefits to the building owner, facility manager, and the contractor. Cold process is suitable for installation in instances where the odor associated with hot kettle fired bitumen is an issue. Cold process avoids the hazards associated with the hot kettle, and transfer of hot asphalt with the associated spill or splash danger. Hot asphalt application requires stringent control of application temperature to avoid the occurrence of inter-ply voids and blisters. With cold process, the application procedure is far more forgiving as the window for the achievement of successful ply bonding is far greater. A further significant advantage of cold-process built up is the lack of restraint by staging considerations. This aspect is valuable in situations like skyscrapers or central roofs where transport of hot asphalt from the kettle to the installation area is a problem.
Built-up roofing is the ultimate choice for tested and proven performance, long service life and system durability. The professionals at Lakewood Roofing can offer expert assistance in weighing design considerations for a successful, long-term built-up roofing solution.
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