Asbestos-Cement Shingles Inspection – Common Problems
Although they require little maintenance, these fiber cement shingles are brittle and can be damaged and cracked by impact. The lower courses are the most vulnerable to damage, and usually they are replaced rather than repaired. When inspecting asbestos shingle siding, look for any cracked, chipped, loose, broken or missing shingles. Usually shingles that have slipped out of place were improperly nailed, or the nails were not rust-resistant and have deteriorated in time. If they have deteriorated, more shingles will slip out of place, so maintenance should be anticipated.
Asbestos-cement shingles were usually installed wit sheathing-paper-backer strips behind the vertical joints in order to provide additional protection against water penetration. Some sections of backer strips might have slipped out of place or are hanging loose between the shingles, but since the shingles were installed over the waterproof sheathing paper replacing the loose backer strips is often not necessary.
The combination of asbestos and Portland cement – the most widely available type of cement – created a highly durable and water-resistant material. In addition, asbestos cement is also fire-resistant, while the inexpensive manufacturing process provided builders with a resistant and economical material. Consequently, asbestos cement shingles became extremely popular in the construction industry, and were often used as a replacement for traditional slate or wooden shingles. Moreover, they could be made to resemble wood and other materials. Flat shingles, wave designs or thatch-like shingles were also manufactured from asbestos cement shingles, and the manufacturing process allowed further customizing the shingles with color. Originally, asbestos cement roof shingles came in grey and white tones, but manufacturers added color to the asbestos cement mix before it dried to create color shingles.
Asbestos cement sheets were large pieces used in many interior constructions. They came in various sizes, but generally they were 12 feet long and 4 feet wide, with a thickness of under one inch. Just as asbestos cement shingles, they were only used in industrial settings, but as manufacturing techniques became more sophisticated, asbestos cement sheets became available in a variety of colors, textures and finishes, introducing such sheets into office buildings as well. Office buildings used the sheets as tables, walls, wall panels and partitions.
In addition, asbestos cement was also widely popular in home siding shingles, because it provided a highly durable siding material, able to withstand the wear of exposure to the outdoor elements. Besides flat siding shingles, manufacturers were also able to produce textured and waved siding panels.