Roof Pitch Rafter Length Formula

The length of rafter per meter of run is 1 1543.

Roof pitch rafter length formula.

Divide this in half and the result is 7 feet. Use the blueprints to establish a pitch for the roof. Pitch is the incline of the roof represented as the ratio of rise to the span twice the run. Note that this is not the actual length of the rafter.

The rafter member will be longer. This calculator is to be used as an estimating tool only. It is the length of this portion of the rafter. If you plan to have overhang etc.

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. Includes result for hip valley factor slope factor and the roof slope in degrees. Area span on the flat please enter area span on the flat in foot. If you add an eaves overhang dimension then the amount the rafter sticks passed the wall will be added to the rafter length.

Rafter length using pitch v r 2 sqrt 1 p 2 where v overhang r roof span p pitch. This means that for every 1m the rafter travels horizontally the angled length of the roof will be 1 1543m. Often you express roof pitch as the ratio between the rise and the run in the form of x 12. Roof pitch is often expressed as a ratio between rise and run in the form of x 12.

Use our online rafter length calculator to quickly compute the length of the shed roof rafter by entering the measurements of overhead length of roof span pitch or angle. You can assess this in two ways either as the roof pitch angles which the rafters make with the horizontal or the proportion between the run and the rise of the roof. The length of the rafter is given from the long point of the ridge cut at the top down along the top edge the board to the same plumb cut on the rafter s notch. Rafter length calculator calculate the length of a rafter from the roof slope ratio of inches per foot and a building width measurement.

In this example the shorter walls are 14 feet long. Roof pitch is simply the slopecreated by the rafter. 1 1543 x 1 610 1 858m. Input the rafter span on the flat eave overhang and pitch of the roof.

All we do now is use a calculator to multiply 1 610 by the measurement in the book. Rise and run means that a 6 12 pitch roof has 6 of rise vertical for each foot of run horizontal. The results are automatically fired as soon as any of the values are entered or altered. 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.

Roof pitch refers to the slope which the rafter creates. Select a roof pitch. 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.