Roof Cuts And Rafter Lengths

Half building width minus 1 2 ridge thickness.

Roof cuts and rafter lengths.

Rafter book page 1 created date. It will help you with plumb and side cuts for hip and rafter down and side purlin cuts and more. For example if the ridge beam is 1 5 inches thick subtract 3 4 of an inch from the overall rafter length. Rise and run means that a 6 12 pitch roof has 6 of rise vertical for each foot of run horizontal.

Marking out the roof rafter lengths onto the timber before cutting step 1. Roof cuts and rafter lengths hancock s 10th edition is a very popular best selling book. With calculations diagrams and tables. 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.

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. See rafter run to outer wall calculator below. 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. The next result is the run.

Determine the camber along the timbers length. 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. Before you can mark the rafter lengths and layout check the. If you add an eaves overhang dimension then the amount the rafter sticks passed the wall will be added to the rafter length.

Roof cuts rafter lengths roofing book. With the tape measure hooked onto the top end transfer your two rafter lengths onto. Rafter length using pitch v r 2 sqrt 1 p 2 where v overhang r roof span p pitch. If you are calculating rafter length from the center of the ridge beam as shown below you will need to subtract half of the thickness of the ridge beam from the top end of the rafter.

Mark the plumb cuts. This is the horizontal measurement from the outside of the wall to the inside of the ridge. Calculate the length of a rafter from the roof slope ratio of inches per foot and a building width measurement. Print full scale rafter plumb cut templates and birdsmouth templates fold template over rafter to mark or cut through.