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Re: Large eave overhang

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Have you thought about cantilevering the truss rather than just the top
chord. It doesn't have to be the entire triangular shape but could be two
parallel members cantilevering out with a depth of 16" for example. 




At 08:31 PM 3/20/00 GMT, you wrote:
>I am working on a wood framed project where the architect wants to have a
>5'-0" eave overhang.  Roof is a 3:12 pitch.  The main roof framing members
>are prefab wood trusses @ 2'-0" on center.  I was looking at using Doug-Fir
>No. 2 lumber.  For a 2x6, using Cd=1.25 and Cf=1.3 I calculate an allowable
>moment of 896 ft.-lbs.  My concern is with a roofer during construction, or
>renovation.  The roofing material will be metal roofing.  Using this  design
>moment the maximum weight of a roofer standing out at the edge of the eave
>would be about 180 pounds.  I don't think this is enough capacity for a
>roofer (please nobody take this personally).
>
>I can fiddle with the Cd value to a higher number, since the duration of
>Cd=1.25 is 7 days, but I don't gain a lot.
>
>What has been the experience of others on the list?  Anybody design a 5'-0"
>eave?  Anybody do it with a 2x6?  What should I specify as loading for the
>truss manufacturer.  I need to stick frame some of the eave at various
>locations.  Any recommendations for or against using a 2x6 and hoping the
>roofer is not too heavy?
>
>Rich
>

David Handy, P.Eng
Ontario, Canada