# What is a roof slope in construction?

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Definition of Roof Slope: roof slope is the amount of (vertical) change in height as a ratio of horizontal distance traveled, also expressed as inches of rise per foot of horizontal run, or cm of rise per m of horizontal run.

## What is the slope of the roof?

The slope of a roof, often referred to as the pitch, is determined by “rise over run” – the roof’s vertical rise in inches for every twelve inches of horizontal length (the run). So a roof with four inches of rise every 12 inches horizontally (run) would have a slope of 4/12 (sometimes displayed as 4:12).

## What is a 1/12 roof slope?

Roof pitch is often expressed as a ratio between rise and run in the form of x:12. For example, a pitch 1:12 means that per every twelve yards of building length the rise will be equal to one yard.

## What is the difference between roof slope and pitch?

The pitch is the measurement of the rise of the roof to the span of the roof and is expressed as a fraction. … The slope is the measurement of the rise of the roof to the run of the roof, and is expressed as inches per foot in a ratio format.

## What is a 3/12 pitch?

Roof pitch is represented in inches rise of 12 inches run. For example a “3 pitch” or “3 in 12 pitch” or “3/12 pitch”, all mean that the roof rises 3 inches, for every 12 inches of it’s horizontal run. … A roof can also be measured in degrees.

## Is there a minimum roof pitch?

Traditionally, a minimum roof pitch of 20° was recommended in BS 5534, but modern tiles and slates have now been designed for applications as low as 15°. It is uncommon to find a roof below 15° but for those very low pitch applications, there are interlocking clay pantiles available, suitable for use down to 12.5°.

## Is a 4/12 roof pitch good?

As well, a slope of 4:12 is most commonly considered the lowest slope for “standard shingle installations”. Most manufacturer and industry recommendations require, or at the very least recommend, special underlayment or other considerations on roofs between 2:12 and 4:12.

## What does a 1/12 pitch mean?

1 over 12 is the lowest of the low slopes. You’ll often find a 1/12 pitch on back patio porches or at the top of an older gambrel roof. 2 over 12 is a little steeper than a 1 over 12 pitch, but not by much. In degrees, low slopes are between 4.76 degrees and 9.46 degrees.

## What is the most common roof pitch?

The most commonly used roof pitches fall in a range between 4/12 and 9/12. Pitches lower than 4/12 have a slight angle, and they are defined as low-slope roofs. Pitches of less than 2/12 are considered flat roofs, even though they may be very slightly angled.

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## What does a 4/12 pitch mean?

A roof that rises 4 inches for every 1 foot or 12 inches of run is said to have a “4 in 12” slope. … The slope ratio represents a certain amount of vertical rise for every 12 inches of horizontal run. For example, a “4 in 12” slope can be expressed as the ratio of 4:12. A “6 in 12” slope is expressed as 6:12.

## How do I calculate the pitch of a roof?

The angle, or pitch, of a roof is calculated by the number of inches it rises vertically for every 12 inches it extends horizontally. For example, a roof that rises 6 inches for every 12 inches of horizontal run has a 6-in-12 pitch.

## Is a 3/12 roof pitch good?

Any roofs up to 3:12 are generally considered “low slope.” In the residential arena, we see lower slope roofs as part of the home’s architectural design. … Then, when you get into roofs of 3:12 or greater pitch, most other metal roofs can be used and that generally is the pitch requirement for asphalt shingles as well.

## What is the steepest roof pitch you can walk on?

Common Roof Slopes Expressed in Rise/Run and Angle + Slope expressed as Grade

Common Roof Slopes Expressed in Rise/Run and Angle + Slope expressed as Grade
Roof Slope Expressed as Rise / Run in Inches Roof Slope Expressed as an Angle Walkability
3 / 121 14.04 ° Easy to walk on
4 / 12 18.43
5 / 12 22.62 °

## What roof pitch is 25 degrees?

Roof Slope in Degrees to Standard Roof Pitch Conversion Tables

Convert Roof Slope from Degrees to Rise-in-Run
Roof Angle in Degrees Roof Slope as Rise-in-Run (X-in-12)
25° 5.596 in 12
26° 5.853 in 12
27° 6.114 in 12
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## How does roof pitch affect cost?

A slope of 6/12 could add nearly another thousand dollars to the price. If you were to choose a 9/12 slope, the national average for a 40 by 50-foot roof would be more than \$8,300. A high slope of 12/12 could cost \$10,000 or more.