Illinois Roofing Practice Exam

Expanded perlite is a lightweight volcanic glass that has been heated and expanded to create a porous material commonly used in insulation and other construction applications. The key characteristic of expanded perlite is its brilliant white color, which results from the natural color of the perlite rock itself. This bright white appearance not only makes it visually distinctive but also contributes to its thermal insulation properties, as lighter colors typically reflect more sunlight compared to darker materials.

In contrast, the other colors listed in the options generally represent different materials or types of aggregates that do not share the same properties or appearance as perlite. Gray, black, and brown materials may be used in construction but are not indicative of expanded perlite, highlighting the unique characteristics of this specific insulation material. This understanding is crucial for professionals in the roofing and construction industry when selecting materials for various applications.