Wood Jack Stud check

[SCEngr1]

I have seen simple and more complex calculations for the checking the stress from roof framing to jack studs. My question is: Can you use simply the Fc (compression parallel to the grain) allowable stress and compare to the fc = P/A? Or is it necessary to compute Kce, Cp, etc. for the more complex Fc'?

Also, is there ever a case to check the shear stress parallel to grain (Fv) for a jack stud?




("You're only as old as you feel." - Satchel Paige)

 

[msquared48]

1. If the stud is long,the allowable stress will be reduced by the equation. Kit should be checked.

2. For wind or seismic loading, it could come into play.

Mike McCann
MMC Engineering

http://mmcengineering.tripod.com

 

[dhengr]

It seems to me that’s a problem to tackle some afternoon when you have a little time to spend and are in the right frame of mind. Then you do it for 1, 2 and 3 ganged jacks along side of full length stud (king stud?); and you do each of these for several different common lengths. Tabulate all of this and you’ve got er made. You might do this with a spread sheet, or some such, and make the whole thing part of your std. wood design aids. I would use the whole formula and NDS methods, P/A just doesn’t cut it. Then, on your plans you literally pick your jambs (J1, J2, etc.) from this tabulation as part of your header design.

 

[DaveAtkins]

Assuming the jack studs and king studs are braced in the weak axis direction by sheathing, buckling in the strong axis direction will control. But it still needs to be checked.

DaveAtkins