How To Figure Rafter Lengths For Roof

Determine the camber along the timbers length.

How to figure rafter lengths for roof.

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. 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. Rafter is the distance between the ridge or hip of the roof to.

The rise of the rafter. Before starting the calculation we need to know some technical terms related to a pitched roof. The rafter member will be longer. Height of the scaffold.

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. If you plan to have overhang etc. Area span on the flat please enter area span on the flat in foot. The length of the rafter.

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. Input the rafter span on the flat eave overhang and pitch of the roof. The results are automatically fired. For example if the roof rises 4 feet and the span is 16 feet twice the run.

Rise and run means that a 6 12 pitch roof has 6 of rise vertical for each foot of run horizontal. 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 run of the rafter. Click the button to calculate the stock size needed for this job.

This calculator is to be used as an estimating tool only. Step 4 add the measurement for the overhang the eaves on the outside wall to the result obtained in the rafter guide to determine the overall rafter length. Note that this is not the actual length of the rafter. It is the length of this portion of the rafter.

Lengths of roofing timber almost always bow slightly. 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. Pitch is the incline of the roof represented as the ratio of rise to the span twice the run. Includes result for hip valley factor slope factor and the roof slope in degrees.