I use it with an adjustable stanley quick square and can cut the whole roof on the ground take all the timbers up and assemble the lot in one go.
Jack rafters hip roof.
Know that the basic skeleton for the roof has to be erected before any jack rafters can be installed.
Since the jack rafters are at an angle to the hip rafter some compound cutting is required to create their housing into the hip rafter.
Thus there are hip jack rafters and valley jack rafters.
A jack rafter is a shortened com mon rafter that may be framed to a hip rafter a valley rafter or both.
All the complicated trigonometry calculations are done for you and there s loads more in there too like diminishing jack measurements and hip rafter lengths and angles as well.
Rick arnold frequent contributor to fine homebuilding and the journal of light construction presenter at jlc live the katz roadshow the remodeling show.
Select the following information by using the drop downs to enter values in feet and inches.
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.
Use the hip roof calculator for an easier way to get started.
When you create a hip roof in a timber frame there are different types of rafters used.
Span for the main rafters measure from outside of wall to outside of wall.
The hip rafters in purple form the roofline and extend from the plate to the ridge.
The jack rafters in turquoise connect from the plate in red to the hip rafter and are of different lengths depending on where on the slope they are placed.
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.
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.
The hip roof framing calculator returns the value of the main rafter the side rafter the length of the hip the height of the knee wall and the lengths of the jack rafters.
The total rise of hip and valley rafters is.
They must must be on the same level.
The first step is to enter the length of the longest jack rafter.
