The main purpose of a pitched roof is to allow rain and snow to slide off of a roof. Typically, the more rain and snow you get in your area, the more the pitch you will need. Also different roofing materials require different pitch levels and building codes in your area may vary.
Rise, run and pitch are common terms used when discussing roof slopes. Pitch, also called “slope” is the number of inches that rise for every 12 inches of horizontal distance; it is expressed as “_” in 12. Roofs steeper than 8 in 12 are difficult to install roofing on, especially if there are also a number of dormers, hips and valleys.
One way to determine the slope of your roof is to use a foot long level and put it on the roof surface. Make sure it is level and then use a tape measure and run it from the free end of the level straight down to the roof surface. The number of inches on the tape measure will be your slope.
When you get an estimate for roof repair or replacement, the pitch will be factored in the roofing estimate. The steeper the roof, the more difficult and sometimes dangerous it is to do the work. Most asphalt roofs are somewhere between 2 in 12 and 4 in 12.
