Why Is the Quality of Asphalt in a Roof Shingle Important In the Winter
Written By: Bob Mann on Dec 29, 2009
The asphalt’s primary purpose in roof shingles is to serve as a waterproofing agent. Also due to the composite nature of the roof shingle, the asphalt serves other functions as well: It holds the granules in place and adds to the overall strength. The quality of the asphalt and the processing of are important to the handling, installation and overall performance of a roof shingle. Good quality asphalt will stay flexible and not dry out or become hard or brittle (too high of volatility). This one particular property is most important in the winter when the temperatures are lower. With too high of volatility a roof shingle increases the chances of cracking and/or blowing off the roof when winds are even under the roof shingles wind rating. A roof shingle with poor quality asphalt (too high of volatility) is also at risk of cracking in the winter when handling and during installation.
There are certain critical asphalt properties that must be monitored by the shingle manufacturer to assure that they meet performance requirements. These are:
Ø The temperature at which the asphalt softens (softening point)
Ø The viscosity or flow resistance
Ø The volatility or rate at which its oils evaporate