How To Figure The Length Of A Roof Rafter

Height of the scaffold.

How to figure the length of a roof rafter.

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. Pitch is the incline of the roof represented as the ratio of rise to the span twice the run. Given here are the formulae to calculate the length of a shed roof rafter to make your roofings stronger and look beautiful. Use your pencil to mark the length directly on the rafter.

The length of the rafter. Calculate the length of a rafter from the roof slope ratio of inches per foot and a building width measurement. Rise and run means that a 6 12 pitch roof has 6 of rise vertical for each foot of run horizontal. The rafter member will be longer.

The rise of the rafter. Before starting the calculation we need to know some technical terms related to a pitched roof. The results are automatically fired. 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.

Print full scale rafter cut templates and birdsmouth templates fold template over rafter to mark or cut through. 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. It is the length of this portion of the rafter. Includes result for hip valley factor slope factor and the roof slope in degrees.

The run of the rafter. If you add an eaves overhang dimension then the amount the rafter sticks passed the wall will be added to the rafter length. 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. For example if the roof rises 4 feet and the span is 16 feet twice the run.

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. See rafter run to outer wall calculator below. Determine the camber along the timbers length before you can mark the rafter lengths and layout check the camber of the timber. Note that this is not the actual length of the rafter.

If you plan to have overhang etc. Rafter is the distance between the ridge or hip of the roof to. Hook your tape measure on to the rafter and measure the diagonal rafter length that you calculated earlier. Half building width minus 1 2 ridge thickness.

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 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.