Hip Roof Framing Purlins

Purlins are not required or needed unless rafters are overspanned and then the purlins serve as support to prevent roof sag deflection due to the overspanned and or undersized rafters.

Hip roof framing purlins.

Enter the extension wall length into wall length and double the extension wall width then minus ridge thickness into the wall width entries. Hip rafter ratio length multiplier hrrlm 18 12 1 5 common rafter length multiplier crlm 13 4164 12 1 11803. The common rafter length can be calculated by the roof ratio length per 12 of run. Divide the rafter length by 12 of run to calculate the roof ratio multiplier.

All angles can be found on the chappell univer. Hip rafters are. Photo above is from a jwk inspections framing pre drwall inspection in the san antonio south teaxas area showing the actual roof framing componenents. Now outline the biggest rectangle inside the building layout.

Porch roof extensions for hip roof porch extensions from an existing building wall you can use half the calculator results. Minus ridge thickness to allow for ridge becoming pole plate roof peak will be slightly higher ridge thick must be same. Hip roofs have hip rafters which are oriented diagonally to the ridge and outside walls. Roof framing geometry kernel rafter lengths roof ratio multiplier.

First of all you need to design the layout of building. Now draw the centerlines for all rectangles that are formed inside. Hip and valley roof framing is no so complex as compared to hip roof framing procedures.