Roof slope multipliers for roof components of sloping roofs multiply by the figures given below to obtain the cost per square foot of horizontal projection.
Standard roof pitch michigan.
0 pitch 1 00x the roof area.
The minimum pitch for a roof is 1 4 12 which translates to 1 4 inch rise to 12 inches of run.
This measurement is best done on a bare roof because curled up roofing shingles will impair your measurement.
You can go by the measurements taken by walking the roof.
Table r905 1 1 2 underlayment application.
Roof slopes are most commonly defined by the rise over run ratio.
Roof pitches exceeding the level of 9 12 or approximately 37 degrees are termed steep slope roofs.
To do that requires basic geometry but fret not you can just refer to tables that are standard in the industry.
A pitch over 9 12 is considered a steep slope roof between 2 12 and 4 12 is considered a low slope roof and less than 2 12 is considered a flat roof.
For roof slopes from two units vertical in 12 units horizontal 2 12 up to four units vertical in 12 units horizontal 4 12 underlayment shall be two layers applied in the following manner.
However you can only use this pitch with built up roofing or specialized synthetic roofing.
Since this is a flat roof or nearly flat roof.
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.
These are utilized in residential applications.
The pitch of a roof is its vertical rise over its horizontal span.
Using roof pitch to order materials.
However most often a ratio of pitch also fraction is slang used for the more useful slope of rise over run of just one side half the span of a dual pitched roof.
The table below shows common roof pitches and the equivalent grade degrees and radians for each.
Roof pitch is a measurement of a roof s slope expressed as a ratio.
If a roof slope rises say 4 inches when measured 12 inches along the bottom of a horizontal roof truss the roof slope is said to be 4 12.
Multipliers used for estimating roof area based on slope.
Rise multiplier rise multiplier 1 to 12 1 01 6 to 12 1 12 2 to 12 1 01 8 to 12 1 20 3 to 12 1 03 12 to 12 1 42 4 to 12 1 06 15 to 12 1 60 5 to 12 1 08 18 to 12 1 80.
I e 4 inches of rise per 12 inches one foot of run.
Although there is no single standard roof pitch used on all sloped roofs factors such as roofing materials and local climate help to determine the appropriate range of pitches for a given building.
Some of the most common roof pitch types are conventional slope type roofs designed with pitch ranging from 4 12 to 9 12.
