Components wind 1

[haynewp]

For a stud wall with sheathing, I usually take the spacing between studs times the length for the trib area, compared to 1/3 width x length. Someone has told me they use the sheathing width times the length because the wind will end up being spread out over several studs and not just effect one. Which is correct?

 

[haynewp]

I think I have pretty much convinced myself I am right. I don't think the plywood is stiff enough and the joints in the sheats could vary.

A different case:
I believe that the tributary wind area on reinf. in a poured concrete wall would get spread over more of a width than it's spacing. This due to the stiffness of the concrete. This is the way I have always treated it. Anyone disagree?

 

[redhead]

ASCE 7-98 defines "effective wind area" to determine Gcp as the span multiplied by the effective width, which need not be less than one third the span length. However, for cladding fasteners you are limited to the actual area that is tributary to the fastener.

 

[haynewp]

I found in "The guide to the use of the wind load provisions of asce 7-95" an example that uses the Height x Height/3 for the trib area of a cmu wall. Note 8 on p. 97 similarly compares this to a 1ft x Height value.
I guess the same would apply for a concrete tilt panel.

 

[fritzee]

You are correct. You should calculate the tributary area as the stud spacing x height.