How is roof slope calculated?

The calculation of roof slope is determined by the ratio of the vertical rise of the roof to its horizontal run. To find the slope in terms of pitch, the total rise is divided by the total run, which gives the slope as a fraction. This fraction is then multiplied by 12 to convert it into a pitch format commonly used in the construction industry, where the slope is expressed as inches of rise per 12 inches of run. This method clearly indicates how steep the roof is, making it an essential calculation for roofing design and installation.

The other options do not accurately describe the process of calculating roof slope. Option A incorrectly suggests that simple multiplication of rise and run determines slope, which it does not. Option C misleadingly implies that subtracting run from rise leads to slope calculation, which ignores the necessary ratio aspect. Option D incorrectly suggests adding rise and run, which does not relate to how slope is typically determined in construction. Thus, the correct method provides a standardized way to express roof slope effectively.