Pitches of less than 2 12 are considered flat roofs even though they may be very slightly angled.
Standard hip roof angle.
Roof pitches exceeding the level of 9 12 or approximately 37 degrees are termed steep slope roofs.
One expression of a hip roof pitch based on this formula would be 4 12 meaning a 4 inch vertical rise for every 12 horizontal inches.
Using these angle definitions i will derive formulas for the sheathing θ s and hip pitch angle θ h given the common pitch angle which i call the roof pitch θ r and plan angle θ p.
Hip roofs are more expensive to build than a gable roof.
Common hip roof pitch.
To derive formulas for the critical angles we need to define some terms which i do in figure 2.
Similar to a cross gable roof.
It has a polygon on two sides and a triangle on two sides.
If we consider the commercial applications then low sloop type roofs are preferred with pitch ranging from 2 12 to 4 12.
Types of hip roofs.
So where two roof sections intersect to form a 90 angle a regular hip or valley and each roof section has for example a 6 in 12 slope the hip or valley rafter at that intersection will have a slope of 6 in 16 97.
Roof pitch and corresponding angles.
Pitches lower than 4 12 have a slight angle and they are defined as low slope roofs.
Use separate hip roofs on homes with different wings.
For high wind areas or strong storms a pitch of 4 12 6 12 18 5 26 5 angle is recommended.
Hip backing angle 15 4 for a good straight fascia add an extra inch or 2 to the tails of all your rafters total length.
The angle at which the roof plane rises will account for a consistent height in inches above the 12 inch horizontal line and is described as the nominator of the pitch calculation ratio.
Pitches above 9 12 are very highly angled and are designated steep slope roofs.
Hip roofs can offer extra living space when a dormer crow s nest is added to a hip roof.
The most commonly used roof pitches fall in a range between 4 12 and 9 12.
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.
This measurement is best done on a bare roof because curled up roofing shingles will impair your measurement.
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.
The line where the two roofs meet is called a valley.
This means if a roof rises 4 in the length of 12 your roof pitch would be 4 12 or 18 43 degrees.
