Roof Drop Per Foot

The slope ratio represents a certain amount of vertical rise for every 12 inches of horizontal run.

Roof drop per foot.

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. Some building codes start at one quarter of an inch per foot or two percent. Anything less than one eighth of an inch may pool on the 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.

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. Adding a covered porch adds exterior space to a house and providing a. No you cannot install metal shingles on a low slope roof. To get the minimum pitch for a metal roof the vertical rise per foot is divided by the horizontal slope.

A roof with a 6 rise for every 12 run has a 6 per foot or 6 in 12 pitch. However an ideal roof drop per foot should be at least one eighth to one quarter of an inch per foot. Anything with a slope of some kind will cause water to run off the roof. A roof protects a house and porch from snow and rain as well as the heat of the sun.

Minimum roof pitch for a covered porch.