Measure the distance between the angled hip rafter and the top of the wall at 20 in 51 cm increments and cut jack rafters to fit.
Roof framing hips and valleys.
A jack rafter is a shortened com mon rafter that may be framed to a hip rafter a valley rafter or both.
Hipped roof construction can seem quite complicated to grasp at first but i m going to break it down and explain each area in detail.
First of all you need to design the layout of building.
The total rise of hip and valley rafters is.
Thus there are hip jack rafters and valley jack rafters.
For any roof slope expressed as x in 12 rise in run the hip and valley factor is determined by finding the square root of rise run 2.
Hip and valley roof framing is no so complex as compared to hip roof framing procedures.
I ll start at the beginning with the easy bits before tackling the more complicated stuff and that way hopefully i ll make it really clear and easy to understand exactly how to set out measure cut and install hip and valley roof rafters.
Rafter is called for only when framing a hip roof but a valley rafter is needed on both hip and gable roofs whenever roof planes intersect.
Divide the rise by the run the run is 12.
The hip and valley factor varies according to the slope of the roof as shown in the table below.
Depending on the size of the roof most hip roofs will have 4 6 short jack rafters that are spaced out every 20 inches 51 cm between the hip rafters and the king common rafters.
Now draw the centerlines for all rectangles that are formed inside.