As further evidence of the virtually endless number of products that contained asbestos, many roofing materials utilized this strong mineral to add protection to the very first area of a home touched by the elements. Although the use of asbestos roofing products was first phased out beginning in the 1980s, many homes, schools and commercial buildings may still contain this material. Two common roofing products individuals should be cautious of are roofing felt and roofing shingles, especially if these products are being replaced.

Asbestos Roofing Felt

Generally installed on the flat roofs of commercial buildings and schools, this product was widely used on “built-up” roofs.  This form of built up roofing was reportedly only in residential use for a short period during the 1970s. Generally found on flat surfaces, built up roofing is made up of alternating layers of roofing felt and asphalt.

Roofing felt itself is composed of asbestos paper saturated and coated with asphalt. About 10 to 15 percent of this form of roofing felt is made up of asbestos, which provided valuable fire resistance, strength and flexibility. Roofing felt most often saw production with chrysotile, or white, asbestos, which is by far the most commonly-encountered form of this mineral. In fact, 95 percent of United States asbestos use was done with chrysotile.

Asbestos Roofing Shingles

Used widely until very recently, asbestos-cement roofing shingle production began in the first decades of the last century. These shingles, composed of asbestos and Portland or hydraulic cement, were lightweight, fireproof and inexpensive. They were marketed as an innovative alternative to traditional roofing materials, such as clay, slate and wood. In addition, pigment could be added to these shingles, boosting their popularity further. In addition, the hydraulic pressing process allowed these tiles to take on various textures, styles and sizes, adding to their great popularity time.

Corrugated asbestos-cement sheathing was another form of asbestos roofing which generally saw use in industrial applications. This form of asbestos roofing, sometimes called asbestos building lumber, could be laid directly on steel roof supports. Its fire-resistance made it especially useful in the industrial capacity it generally filled.   

Asbestos Roofing Material Risks

Asbestos shingles were produced in the 1980s, meaning many structures likely remain protected by these products. Although relatively safe when in good condition and undisturbed, the age of these asbestos roofing products means these products are likely in a dangerous state today. Although located on the outside of these buildings, once asbestos fibers are released, they can cling to clothing and hair and get brought inside buildings, where they pose a greater chance of being inhaled or ingested and causing a lethal disease.