Roof Drop Per Foot

A roof with a 6 rise for every 12 run has a 6 per foot or 6 in 12 pitch.

Roof drop per foot.

Anything with a slope of some kind will cause water to run off the roof. A roof that rises 4 inches for every 1 foot or 12 inches of run is said to have a 4 in 12 slope. To get the minimum pitch for a metal roof the vertical rise per foot is divided by the horizontal slope. If the rise is 6 inches for every 12 inches of run then the roof slope is 6 in 12 the slope can be expressed numerically as a ratio.

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. Anything less than one eighth of an inch may pool on the roof. Most metal roofs will have minimum pitches of three in twelve but this might sometimes go down depending on whether there are special installation procedures issued by the manufacturer regarding that particular roofing material. Roof pitch or slope is a measure of vertical rise to horizontal run expressed in inches per foot.

However an ideal roof drop per foot should be at least one eighth to one quarter of an inch per foot. A roof protects a house and porch from snow and rain as well as the heat of the sun. No you cannot install metal shingles on a low slope roof. The slope ratio represents a certain amount of vertical rise for every 12 inches of horizontal run.

Some building codes start at one quarter of an inch per foot or two percent.