Standard Roof Truss Angles

Pitches of less than 2 12 are considered flat roofs even though they may be very slightly angled.

Standard roof truss angles.

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. Pitches above 9 12 are very highly angled and are designated steep slope roofs. This means if a roof rises 4 in the length of 12 your roof pitch would be 4 12 or 18 43 degrees. If the overhang exceeds 2 5 feet we will need to use a larger top chord for the overhang typically a 2 6 top chord for the truss.

It s often used for sheds garages or extension of an existing roof. Commonly it is 3 4 th of span as per gothic rafter must be equal to span. Angle the angle of a roof is the same as the roof s slope except instead of being represented as x 12 it is represented in degrees. Common or standard trusses are symmetrical and have standard four inch heels.

A 4 12 is a roof slope that rises by 4 inches for every 12 inches across. Usually average roof pitch is determined using the same roof length method. A mono truss roof allows for more sunlight and visual space proper drainage and relatively cheaper. As we will see below there are several different types of designs and this will impact the angles and designs of the overall truss.

A mono truss is a one sloped truss that forms a right angle triangle. The most commonly used roof pitches fall in a range between 4 12 and 9 12. A truss with the same pitch and heel on both sides and a peak at the center is called a common truss. Roof pitch and corresponding angles.

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. The truss is a framework consisting of rafters posts and struts which supports your roof. This forms an angle of 18 5 between the horizontal section and the roof and creates a gentle incline that is seen as a midpoint between a low pitch and medium pitch roof. Greek says one must keep rafter length in range of 1 9 to 1 7 th of span but as per roman style the standard dimensions are kept about 1 3 to 2 9 th of span with an angle of 23 to 24 degree.

A standard overhang is 16 24 inches but the overhang can be any length you wish. Pitches lower than 4 12 have a slight angle and they are defined as low slope roofs.