This historic digest is part of a series published by the U.S. Department of Commerce’s National Bureau of Standards on the technical characteristics of building materials used in the construction of affordable housing units. Each digest presents condensed, essential facts regarding its given topic, and is intended for use by staff at federal agencies, manufacturers, trade associations, and builders. This publication discusses materials used in the construction of roofs composed of layers of bitumen-saturated felt. The previous digest, #39, also addressed the topic of bituminous built-up roofing.

This report is part of the collection of scanned historical documents available to the public.