Roof Cuts And Rafter Lengths Pdf

The difference in length of the jack rafter spaced 16 or 24 inches on center is also shown in the table.
Roof cuts and rafter lengths pdf. Calculate the length of a rafter from the roof slope ratio of inches per foot and a building width measurement. Calculations for roof frames roof cuts and rafter lengths. All roof rafters should be identical so follow the same steps to measure the plumb cut tail cut and birdsmouth cut. A must for all builders.
A rafter that runs from a hip rafter to a valley rafter perpendicular to the roof ridge dormer rafter. The number of rafters needed will be determined by the length of your roof. If you add an eaves overhang dimension then the amount the rafter sticks passed the wall will be added to the rafter length. Rafter table type 1.
Angle the angle of a roof is the same as the roof s slope except instead of being. Slope the slope of a roof is represented as x 12 where x is the number of inches in rise for every 12 inches of run this is very useful information for many purposes especially for roof framing the slope sometimes called pitch is calibrated on speed squares. At this point you ve cut 1 roof rafter. It will help you with plumb and side cuts for hip and rafter down and side purlin cuts and more.
Well known throughout the industry as the little red roofing book it can be or should be found in the back of every roofer 039 s ute. This 88 page pocket size edition is in metric updating all the old calculations and it is a very easy. Roof pitch calculator results explained. Once you ve measured the run of a rafter simply look up the right table in the ready reckoner for your roof pitch angle and using the measurements relevant to the span of the wall plates it tells you everything from all the common rafter lengths plumb and seat angles to the length of the hips the jack rafter cuts and several others are.
Rise and run means that a 6 12 pitch roof has 6 of rise vertical for each foot of run horizontal. Where the jack hip or valley rafter needs side cuts the cut is given in the table. Includes result for hip valley factor slope factor and the roof slope in degrees. 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.
With calculations diagrams and tables. Buy roof cuts and rafter lengths at angus robertson with delivery an easy to read handy pocket guide to roof construction measurements and details. The other type of table gives the actual length of a rafter for a given pitch and span. For example this rafter would be used when remodeling or adding on to an existing structure.
A rafter that sits on top of the main roof without cutting into the main roof. If you enter a value for. Rafter book page 1 created date.