Florida InterNACHI State Practice Exam

The slope ratio of a roof is typically expressed as a ratio of the rise to the run. In this case, the rise is 4 inches, and the run is 12 inches. When calculating the slope ratio, you simply express these two measurements in fraction form.

By taking the rise (4 inches) over the run (12 inches), you get a slope ratio of 4 inches over 12 inches. This can be simplified, but the original form clearly shows that for every 12 inches of horizontal distance, the roof ascends 4 inches vertically.

This ratio is important in construction and roofing because it helps determine how steep or flat a roof will be, which can affect drainage and structural integrity. Understanding slope ratios allows builders to adhere to necessary specifications and standards for roofing systems.