|Roofing Contractors' Page
Roofing Contractors' Page
It's quite often to find asbestos in roofing material. The following is a list of roofing materials that may contain asbestos.
Silver paint associated with roofing is like the biggest source of asbestos among all roofing products in terms of frequency of occurrence. Statistically, more than half of the silver paint tested contain 2% to 7% of asbestos, often Chrysotile, the most common type of asbestos. When the percentage is low, it's very easy for inexperienced analyst to skip or overlook the asbestos, because the smearing effect of the paint particles. It is imperative to use an accredited lab for your testing. Silver paint on roofing is more often applied along edges of the roof or near the gutters, although it can be uniformly applied over the entire roof.
Patching material are often applied to seal the edges of the roof, or between individual roofing tiles. Many times, it's found to contain asbestos even though the associated roofing shingles are negative. The positive patching will appear gray surfaced when it weathered with time. The percentage for this kind of patching is normally 2% to 5%.
Most of the asphalt shingles themselves are negative for asbestos testing, but if it's multi-layered, look for the asphalt felt that is used to reinforce the shingles. The felt is often a lower or intermediate layer, and it will contain fairly high percentage of asbestos if they are positive, normally 5% to 25%.
Black tar is the more fragile, and shining component that associated with roofing material. Although they are often negative for asbestos testing, they can contain small amount of asbestos, usually not exceeding 2%. Similar to silver paint, it requires high skills from an analyst to identify asbestos from it.
Roofing Tile (Transite Tile)
Like siding tile, this kind of material may contain high percentage of asbestos, ranging from 5% to 35% of Chrysotile.
Metal and Wood Tile
They are normally negative for asbestos testing, but do look for associated patching or silver paint that may contain asbestos as stated earlier.