Duplex Pipe Covering

Duplex pipe covering is a material which was used in construction of residential, commercial and pub lic buildings to insulate heating and water pipes from other construction components, such as wood studs and joists. The material was manufactured as a type of fibrous paper, allowing it to be wrapped securely around heating and plumbing pipes and ductwork. Often, the paper was manufactured with a unique honeycomb design, using embedded air pockets to increase the insulation value of the material.

Duplex pipe covering and asbestos

Asbestos is a silica-based mineral which occurs in a fiber-like form. As a result, asbestos is both flexible and strong, in addition to providing excellent heat and sound insulation. The fibrous nature of asbestos also made it an easy material to incorporate into materials like duplex pipe covering, which needed to be heat resistant, insulative, and flexible, allowing it to wrap around various sizes and shapes of pipe and ductwork in a wide variety of building applications.

When duplex pipe covering was initially manufactured, no one realized the potentially deadly health effects of asbestos. As a result, asbestos was used widely in literally thousands of construction materials, until federal legislation in 1977 made it illegal to incorporate asbestos in the manufacture process of any construction material. The legislation fell short of banning the use of these materials, however, and existing supplies of asbestos-laden building materials wound up in many buildings built up until the mid-1980s.

Certainly, anyone who worked in the manufacture or installation of duplex pipe covering prior to the mid-1980s was undoubtedly subjected to substantial risk of asbestos exposure. But the risk is still present. Any residential or commercial building today which was built prior to the mid-1980s probably contains at least some asbestos construction or HVAC materials.

In consequence, any renovation or remodeling work that disturbs or removes duplex pipe covering puts the contractor, as well as anyone else in or near the construction area, at risk for asbestos exposure. But asbestos fibers may become dislodged even without renovation work. As asbestos ages, it degrades, becoming brittle and breaking down. Even the movement of local air currents can disrupt these fine fibers, causing them to become airborne where they may be inhaled. Ductwork applications pose special risks, since these fibers can enter the system, spreading throughout the building or home.

Last modified: December 09 2009.