What is a roof pitch?

The roof pitch is defined as the angle of the roof, and it's calculated by the number of inches it rises vertically for every 12" it extends horizontally. This angle is measured by placing a pitch gauge directly on the roof and taking an accurate reading.

This calculation is important because each of VELUX's skylights and flashing kits are engineered with specific pitch requirements that match a roof's slope in order to effectively drain water off of the skylight.