If a rectangle 3'-6" X 2'-0" fits between any of the members, a 20 PSF Live Load needs to be applied in that area. Attic live loads are concurrent with roof live load. Use the ASCE 7 load combinations.
You need to divide all of the results from the different load combinations by the load duration factor, CD, using the largest factor.
DL=10 PSF
FLL=40 PSF
SL=50 PSF
WL=15 PSF (POSITIVE WIND PRESSURE)
Load combinations from ASCE 7-05 (Allowable Stress Design)
1) DL CD1 = 0.9...
@medeek
I have used some of your tools from your website and find them very helpful. Thanks for sharing, they are a great time saver for finding the correct design loads.
Thanks again, it is nice to "meet" the designer!
I've been designing wood structures for about 20 years now, that is 95%...
@medeek
I generally use 0.131 X 2 1/2" or 3" nails. It depends on what the factory / contractor already has in his nail guns. 0.131 nails are ubiquitous in the factory built structures industry and most factories and set crews have this size nail gun. I don't worry about the 1/2" of nail that...
use SPF for most framing, especially walls, floors and ceilings with drywall attached. Using SP for headers if SPF doesn't work is fine as the dimensional changes don't have a big effect on the lower members. In our area (central and northeast PA) DOug Fir has become a more economical choice...
Refer to NDS. Both the angle of load (withdrawal + shear) is addressed....I believe it is Harkinsons formula, and the lag design parameters are specified. Look in the footnotes of the connection tables for the bending yield stress and in the code itself for the bearing stresses. The AISC does...
Medeek, what is this "truss calculator" you refer to?
I work in the modular housing industry and our roofs are usually a combination of pre-engineered wood trusses (mitek, etc.), factory built rafter systems and plain old simple framing with a ridge beam. We use gusset plates all of the time...