How To Figure Rafter Lengths For Roof

Pitch is the incline of the roof represented as the ratio of rise to the span twice the run.

How to figure rafter lengths for roof.

It is the length of this portion of the rafter. Lengths of roofing timber almost always bow slightly. Height of the scaffold. Rise and run means that a 6 12 pitch roof has 6 of rise vertical for each foot of run horizontal.

For example if the roof rises 4 feet and the span is 16 feet twice the run. Rafter is the distance between the ridge or hip of the roof to. Before starting the calculation we need to know some technical terms related to a pitched roof. The length of the rafter.

Note that this is not the actual length of the rafter. Determine the camber along the timbers length. Area span on the flat please enter area span on the flat in foot. Includes result for hip valley factor slope factor and the roof slope in degrees.

Contents1 rafter of roof 2 span of roof 3 rise of roof 4 pitch of roof 5 run of roof 6 exmple 1 7 example 2 8 calculate rafter length using angle. Calculate the length of a rafter from the roof slope ratio of inches per foot and a building width measurement. While making roofing for your house with the roof rafters it is important to know the rafter length to make the roof seat perfectly on the rafter. If you plan to have overhang etc.

Using the appropriate roof pitch table in a rafter cutting guide such as 4 12 determine the length of each rafter based on the correlating measurement shown for 7 feet. If you add an eaves overhang dimension then the amount the rafter sticks passed the wall will be added to the rafter length. This calculator is to be used as an estimating tool only. The rafter member will be longer.

Calculate the length of common rafters with this free and easy online tool by entering a dimension for the roof width selecting a pitch for the roof and the thickness of the ridge. The rise of the rafter. The results are automatically fired. Given here are the formulae to calculate the length of a shed roof rafter to make your roofings stronger and look beautiful.

Click the button to calculate the stock size needed for this job. 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 dotted line is how the rafter length measurement is used measure from the point at the top down the length and plumb a line there. Before you can mark the rafter lengths and layout check the camber of the timber.