Max overhang of a 2×4 rafter tail
joenorm
| Posted in General Questions on
I specified 3′ overhangs with my trusses with a 2×4 top cord.
I asked specifically and the truss company approves this but it is the max.
At the gable ends there are two lowered trusses so outlookers on edge can fly out(6′ inside of building, 3′ overhang).
I can always shorten the overhang if it seems too long for a 2×4 but I’d like to keep them as long as possible. 3′ does a good job shading the summer sun.
The roof is just steeper than 2:12 and I live in climate 4C so very little snow load. Trusses are 2′ OC
My concern is the eave sagging over time if I take it too far.
Thanks
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Replies
Joe,
Your problem is at the corner of the roof at the eaves. Gable trusses are only dropped over the area of the building, not the overhang. So the corner is supported by one 2"x4" located usually 2 to 4 ft in from the exterior wall, and the rough fascias, making for a weak spot you feel when you walk the roof. With a 3ft overhang that corner is going to be pretty soft. I wouldn't go beyond 2 ft without additional support like the brackets you traditionally see on Craftsman houses.
You may find this useful in visualizing the situation:
http://www.cascade-mfg-co.com/media/a-builders-guide-to-trusses.pdf
Excellent truss resource. Thanks!
Jaccan,
Yeah - a lot easier to understand what's going on than standing on site in the rain trying to decipher the engineering package that comes with the trusses.
Thanks Malcolm,
I was wondering about this part of the roof, definitely seems like a weak area. The truss people told me to tack on dummy outllookers here but of course they don't provide much support, if any at all. Can you think of any other simple solutions to address this while keeping the bigger eaves?
A few things come to mind.
I wonder if the 3 ft overhang is as important on the gable end as it is at the eaves? If not, a 3 ft overhang as the eaves and a 2ft one on the gables would be easier and sturdier.
You can use a beefier finished fascia to contribute to the rigidity of the gable ends. A 2"x8" attached to the rough fascia will help a lot.
If they fit with the rest of the architecture, Craftsman style brackets would allow any depth overhang you wanted.
You can also run a 2"x structural member out to cantilever and pick up the overhang, as I did in the attached photo.