Roofing Felt
Roofing felt is a common roofing material used on flat roofs of public, commercial, and residential buildings, as an underlayment for shingles or as the primary covering in combination with a thick coating of asphalt or other sealer. Roofing felt also offers an added layer of insulation and resistance to fire and water penetration. In order to be effectively fit to individual roof profiles, roofing felt must be flexible and able to be easily cut.
Roofing Felt and Asbestos
Like many other construction materials, roofing felt manufactured prior to the mid-1970s contained a large percentage of asbestos. Originally mined in the 1800s, asbestos was revered by manufacturers of construction and industrial materials for its insulating properties, as well as its ability to withstand changes in temperature and moisture without breaking down. Asbestos is part of the mineral family known as silicates, which are one of the most abundantly occurring mineral families in the world. This only made it more valuable to manufacturers, since its widespread availability made it both a convenient and inexpensive material.
When mined, asbestos appears as a solid mineral, but it is actually composed of millions of tiny strands, or fibers. This characteristic makes it especially strong, and easily molded or shaped into nearly any form. But these tiny strands also pose serious and even deadly health risks when inhaled or ingested. When these fibers enter the body, they irritate and scar organs and other tissues, and can cause conditions such as asbestosis, mesothelioma, and lung cancer over time.
These dangers did not become apparent until the 1970s. In 1977, following a series of studies evaluating the risks associated with asbestos exposure, the United States acted to ban the use of asbestos in the manufacture of construction and industrial materials. But by then, millions of men and women had been exposed to the fibers.
Existing stockpiles of roofing felt and other materials were allowed to be used until depleted, meaning that buildings constructed well into the 1980s may contain asbestos-based materials.
Asbestos fibers are easily released when disturbed through construction or renovation processes, and are more easily released as the material ages and becomes brittle.
If you worked in the roofing industry, you may have been exposed to asbestos. It can take decades for the symptoms of asbestos-related diseases to become apparent, and you should speak with your health care specialist as soon as possible regarding your possible risks of exposure.
Last modified: December 28, 2010.
