Standard Roof Truss Angles

A standard overhang is 16 24 inches but the overhang can be any length you wish.

Standard roof truss angles.

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 4 12 is a roof slope that rises by 4 inches for every 12 inches across. This measurement is best done on a bare roof because curled up roofing shingles will impair your measurement. This is useful because sometime you may need to cut a bevel with your circular saw that is not calibrated using roof pitch style this setting on circular saws is calibrated in degrees.

A truss with the same pitch and heel on both sides and a peak at the center is called a common truss. 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. A mono truss is a one sloped truss that forms a right angle triangle. Pitches of less than 2 12 are considered flat roofs even though they may be very slightly angled.

Usually average roof pitch is determined using the same roof length method. The most commonly used roof pitches fall in a range between 4 12 and 9 12. 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. 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.

This means if a roof rises 4 in the length of 12 your roof pitch would be 4 12 or 18 43 degrees. Pitches lower than 4 12 have a slight angle and they are defined as low slope roofs. 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.

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. A mono truss roof allows for more sunlight and visual space proper drainage and relatively cheaper. We can also build a cantilever for the overhang which is where the bottom chord of the truss continues beyond the wall. The truss is a framework consisting of rafters posts and struts which supports your roof.

Roof pitch and corresponding angles. Pitches above 9 12 are very highly angled and are designated steep slope roofs.