C&C or MWFRS 1

[dgkhan]

For wall studs (2x6) and roof truss (wood) I shall use C&C pressure or MWFRS?This is for a typical wooden house.

 

[COEngineeer]

studs I use CC, for truss I would use MWFRS. At least that is what the truss guy was saying when I went to a seminar.

Never, but never question engineer's judgement

 

[Lion06]

I agree with COEngineer except I believe you should use C&C for the truss members (Use MWFRS for the support connections) - I think I read that in Breyer.

 

[COEngineeer]

I concur.

Never, but never question engineer's judgement

 

[JAE]

Use CC for all of the above unless the tributary area of the affected member is greater than 700 s.f., then use the MWFRS.

If the member is truly part of the main wind force resisting system then check the member for both.

A stud usually is not a MWFRS member unless it is part of a shear wall design.

A roof truss can be part of the MWFRS if it is part of a moment frame - but with wood that is usually not the case either.

 

[dgkhan]

Thanks JAE,
I figured this too but contractor is pushing that I am over killing. This is I am doing for Louisiana for 150 MPH and traditional 2x6 @ 16" c/c SPF # 3 is not working. Any body has idea what is good option for this area.

 

[COEngineeer]

double it up or use LVL. Once you combine wind and compression, I wouldnt be supprised it doesnt work. How tall are the studs?

Never, but never question engineer's judgement

 

[KBVT]

Reduce spacing or double up the studs, not that uncommon of a design when you're looking at wind speeds that high.

 

[rday]

I'm with JAE.

 

[SteveGregory]

Stud and CMU walls are C&C for out of plane bending and axial loads. When loaded as shear walls, they are MWFRS.

 

[frv]

SteveGregory and JAE are correct, IMO.