Hi, I'm Dave Osborne. With over 50 years experience as a journeyman carpenter, foreman and contractor in heavy construction I enjoyed working with apprentices and sharing the tricks of the trade that others shared with me. Now I get emails from Members all over the world and we include many of my answers in our Free Monthly Newsletters. Some of my answers include drawings and instructions specific to a project, but may also answer your questions. I use correct construction terminology, so you can confidently inform your building supply dealers or contractors exactly what you need.
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A rafter table is commonly imprinted on the steel square (carpenter square, rafter square, framing square). I've revised it a bit to include angles, instead of side cuts for hip and valley rafters which aren't used much. [for info on how to use these tables see Rafter Tables on the Framing Square]
|Roof Pitch:||Length of common rafters per foot of run||Length of hip or valley rafter per foot of run||Difference in length of jacks on 16" centers||Difference in length of jacks on 24" centers||Angle in degrees|
|2||12.16||17.09||16 1/4||24 5/16||9 1/2|
|3||12.37||17.23||16 1/2||24 3/4||14|
|4||12.65||17.44||16 7/8||25 3/16||18 1/2|
|5||13.00||17.69||17 5/16||26||22 1/2|
|6||13.42||18.00||17 7/8||26 7/8||26 1/2|
|7||13.89||18.36||18 1/2||27 7/8||30 1/4|
|8||14.42||18.76||19 1/4||28 7/8||33 3/4|
|10||15.62||19.70||20 7/8||31 1/4||39 3/4|
|11||16.28||20.22||21 3/4||32 5/8||42 1/2|
Dave(Ask Dave) (About Dave)
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