Roof Pitch Rafter Length

The angle or pitch of a roof is calculated by the number of inches it rises vertically for every 12 inches it extends horizontally.

Roof pitch rafter length.

If you plan to have overhang etc. For example a roof that rises 6 inches for every 12 inches of horizontal run has a 6 12 pitch. Determine a thickness for the ridge and use the drop down to select it. Roof pitch is often expressed as a ratio between rise and run in the form of x 12.

Visit the roof framing page for more information on cutting roof rafters and visit the roof pitch calculator for determining rafter lengths based on rise and run. It is the length of this portion of the rafter. The hip roof framing calculator returns the value of the main rafter the side rafter the length of the hip the height of the knee wall and the lengths of the jack rafters. Use the blueprints to establish a pitch for the roof.

For example in the rafter span table below the highlighted cell in the 40 live load table indicates that 2 x 8 southern yellow pine joists that have a grade of 2 that are spaced 24 apart can have a maximum span of 10 feet 3 inches 10 3 if designing for a live load of 40 lbs ft 2. It can be assessed in two ways either as the angle the rafter makes with the horizontal or the proportion between the rise and the run of the roof. For example if the roof rises 4 feet and the span is 16 feet twice the run then the pitch is 4 16 or 1 4. High pitched roofs often need extra fasteners and their pitch can be as high as 21 12.

Includes result for hip valley factor slope factor and the roof slope in degrees. If you add an eaves overhang dimension then the amount the rafter sticks passed the wall will be added to the rafter length. The rafter member will be longer. You can also calculate roof pitch even without using a roof slope calculator.

Note that this is not the actual length of the rafter. Pitch is the incline of the roof represented as the ratio of rise to the span twice the run. They have a pitch ranging from 4 12 to 9 12. Calculate the length of a rafter from the roof slope ratio of inches per foot and a building width measurement.

Select the following information by using the drop downs to enter values in feet and inches. Rafter length using angle v r 2cos a rafter length using pitch v r 2 sqrt 1 p 2 where v overhang r roof span p pitch. Rise and run means that a 6 12 pitch roof has 6 of rise vertical for each foot of run horizontal. The pitch of a roof is its vertical rise over its horizontal span.

Our roof rafter calculator tools are handy for calculating the number of rafters needed rafter length calculator lineal feet of rafter board feed in ridge and sub facia and the total board feet in the roof. The results are automatically fired as soon as any of the values are entered or altered. There is no standard universal pitch of roof. Select a roof pitch.

Roof pitch is simply the slopecreated by the rafter.