Asbestos Slate Siding
Exterior building envelopes built throughout the twentieth century relied heavily on asbestos-cement products, commonly commercialized under trade names such as Transite, Eternit, and Careystone. Manufactured by blending portland cement with ten to thirty percent chrysotile or amphibole asbestos fibers, asbestos-cement roofing shingles, corrugated sheets, and siding panels provided unprecedented weatherproofing, rot resistance, and fire immunity. While intact exterior panels remain non-friable, aging, weathering, power washing, and breakage during siding replacement require specialized handling to prevent environmental contamination.