Roof slope is generally expressed in the form of vertical rise:horizontal run. As an example, a roof could rise 5 inches for each 12 inches of horizontal distance. This would be a roof with a slope of 5:12.
Roof slope is important because the slope dictates how the roof is applied. The standard application practices detailed in the PABCO® Installation Instructions are intended for roofs with a slope between 4:12 and 20:12. Special application practices (also found in the PABCO® Directions For Application) are used if the slope is lower or steeper.
Do not use PABCO® shingles if the slope is less than 2:12. See the PABCO® Installation Instructions for additional details and related information.