Avoid scaring clients and needlessly complicating the transaction by providing incomplete information about concerns with asbestos in drywall compound!
In mentioning that asbestos is commonly found in drywall compound in homes built before 1981 be sure that your client understands the circumstances under which it is regulated.
Asbestos becomes regulated at concentrations exceeding 1%. At concentrations of 1% or less, asbestos is typically unregulated and can be treated as non-asbestos.
Under a 1995 ruling, the percentage is calculated as a percentage of the drywall assembly. This means the drywall and compound together, not just the compound. This means that if drywall compound contains 5% or less of asbestos and the compound is less than ¼-inch thick (most textures), the percentage of asbestos in the drywall assembly would be less than 1% and would not be regulated.
Probably the only time asbestos in compound would actually need expensive abatement is when the compound contains a high percentage (it can contain up to about 10%) and was applied thickly.
This also important for inspectors who do a lot of pre-list inspections to know about because it will allow the seller to refute asbestos comments made by a buyer’s inspector who doesn’t understand how the percentage is calculated.
Note: This generally applies in the USA, not Canada. Inspectors should check to make sure that their state regulations are not more stringent.