Roof Cut Factor

This measurement is best done on a bare roof because curled up roofing shingles will impair your measurement.

Roof cut factor. A a roof with a 6 rise for every 12 run has a 6 per foot or 6 in 12 pitch. A 7 5 variance of waste on a 30 square roof would be 2 33 squares. Two most common methods 4 12 or 4 12 are used for marking the pitch of a roof. Hip and valley factor rafter length in decimal feet.

That s because it is the smaller cut up hip roofs that can often have the highest waste percentage. For roof slopes expressed as x in 12 rise in run the roof pitch multiplier is determined by finding the square root of rise run 1. The combination of two numbers are used to display or show the roof pitch. You can consult the following chart to discover the slope factor and hip valley factor.

Download the slope chart pdf. When outfitting your residential or commercial structure with products from everlast roofing it s important to know the incline or pitch of your roof. Length of the rafter. Multi level complex roofs are difficult to estimate.

A roof pitch multiplier also called a roof pitch factor is a number that is multiplied by the area covered by a sloped roof to produce the area of the actual surface of the roof. Note the word large wasn t included. On blue prints architects engineers usually display the pitch of a roof in the format shown on the image where number 4 represents a rise and number 12 represents a length. With the saw bevel angle set to 45 cutting hips and creepers at the plumb cut angle will produce correct side angles.

This way the pitch of the roof and the slope of the roof can be measured. Knowing how to make this calculation will make your roof construction project easier and will ensure the safety and success of your roofing project once completed. Roof pitch or slope is a measure of vertical rise to horizontal run expressed in inches per foot. This roof slope factor table also consists of hip and valley factors to measure the possible hips and valleys.

The picture below shows the pitch of a 7 12 roof slope meaning that for 12 of horizontal measurement roof run the vertical measurement roof rise is 7. An angle cut is a very common cut needed for constructing rafters for any roof. Pitch is thus the ratio of the rise in inches to a 12 inch run and is often expressed using a semicolon for example 6 12. That s 500 to 600 variance on the estimate.

The higher the slope the steeper it is.