Which common building materials are likely to contain asbestos?

The correct answer focuses on insulation and lead pipe insulation as common building materials likely to contain asbestos. Asbestos was widely used in insulation materials, especially before the health risks of asbestos exposure were fully understood. It was prized for its fire-resistant properties and effectiveness for thermal insulation.

Insulating materials, such as pipe insulation and blankets, often contained asbestos fibers, making them a significant concern in older buildings. Lead pipe insulation, common in homes constructed before the asbestos ban, frequently used asbestos for its insulating qualities.

While drywall and ceiling tiles have been known to contain asbestos in certain formulations, insulation specifically highlights the prevalent use of asbestos. Wood paneling and flooring, as well as paint and varnish, are generally not significant sources of asbestos, as they do not typically require the fire resistance which asbestos provided. Thus, insulation is the most fitting answer when discussing common building materials that likely contain asbestos.