Types of Asbestos Roofing Shingles

Asbestos Use

• When people think of shingles made of asbestos, they often believe that the whole shingle is made of asbestos. Instead, other materials such as cement often make up most of the shingle, with the asbestos content being only 5 to 35 percent. While asbestos was a popular roofing material in the last century, the material has since fallen into disfavor due to its link to cancer. Other materials such as slate and clay are now more popular.

Chrysotile Asbestos

• Shingles made of chrysotile are the only ones containing asbestos that are still manufactured in the United States in 2011. The asbestos in these shingles is surrounded by cement or resin and is thus less dusty. Although studies have proven this material to be safe, the government still regulates its use. Chrysotile has not only proved durable but also cost effective; it is also used in textiles, plastics and numerous sealants as well as shingles, according to the Chrysotile Institute.

Transite Shingles

• Transite shingles were once popular and can still be found on many older buildings. These shingles mixed asbestos with Portland cement to make shingles. They became popular in the 1900s because they weathered well, did not warp or rot, and were not susceptible to insect attack. Many of these roofing shingles still exist on buildings but are being replaced with other materials as they wear out.

Roofing Felt

• Another type of roofing material popular in the 1900s and still found on some buildings, especially sheds, is roofing felt. This is actually a heavy paper filled with asphalt with asbestos added to give fire resistance. While some roofing felt is still used today, the asbestos fibers have been replaced by chrysotile. Roofing felt is often used on buildings with flat roofs.