Does Old Johns Manville insulation have asbestos?

Old Johns Manville insulation can contain asbestos depending on its age and product type, and this is an important safety distinction. Johns Manville was historically the largest manufacturer of asbestos-containing insulation in the United States from the 1920s through the early 1970s. Products that often contained asbestos included Johns Manville Thermobestos and Kaylo calcium silicate block and pipe insulation, Asbestospun pipe insulation, and certain asphalt roofing and wallboard products. These were white to grayish, cement-like insulation used around boilers, pipes, and furnaces. If your home has insulation installed before 1975 that is on pipes, ducts, or as block insulation and looks chalky or corrugated, it may contain asbestos. However, not all old Johns Manville fiberglass insulation contains asbestos. Johns Manville also made fiberglass batts in the 1960s and 1970s that were asbestos-free. The company phased out asbestos from most products by 1974 to 1975 after OSHA regulations. Any Johns Manville insulation purchased today from Home Depot, Lowe's, or lumber yards is completely asbestos-free and certified. If you have old insulation in an attic that is loose-fill grayish-brown and pebble-like, that may be vermiculite, often from Libby, Montana, which can be contaminated with asbestos, but that was not primarily a Johns Manville product. If you suspect asbestos, do not disturb it. Have a sample tested by an accredited lab and hire a licensed abatement contractor if needed.