The wind pressures are specifically said to be vertical "projection": see note 8 in figure 6-2.
Also, I stated the pos/neg toward/away clause, I was asking about the arrows pointing to and away in some, but not all, of the zones.
I am having trouble understanding which way the force is acting. There is a clause that states, "plus and minus signs signify pressures acting toward and way from the projected surfaces, respectively;" however the horizontal and vertical forces on a windward roof stay negative until the slope...
Yes, I see that now. I also notice that there is only a windward pressure on the MWFRS in the simplified method. Do they combine the windward and leeward pressures into one windward pressure?
That seems pretty conclusive. How about a case where you have an effective area less than 10 ft^2? Can that be used as a minimum, would one have to extrapolate? I'm assuming that, for the the simplified version, that you can interpolate for intermediate values. However, I do not see a provision...
Angre, thanks for your contribution to the discussion.
Stenbrook, do you think it is not acceptable to consider a plane of a roof to be a system, and therefore use the total area of the plane? Of course, this is paying proper attention to which zone(s) lie in the plane.
So if you have a wood-framed roof that is sloping downward, then the effective wind area would be continuously decreasing with the length of the rafters? Is this true?http://files.engineering.com/getfile.aspx?folder=0508e412-d252-492d-aabc-da06e25ce360&file=Capture.PNG
Greatone, you should send an email to APA and ask them directly. I think they will get you the answer you need. Are you also using OSB, because gyp only adds about 90 PLF of shear capacity alone. Can you put the gyp behind the soundboard? It seems like that wouldn't change the shear added by the...
What I have been doing is using the simplified version for C&C and the analytical method for MWFRS. As far as C&C my concern is what psf rating to spec the windows, so in that case the effective area would be the area of the window?
Also, I'm curious to know where you got the wall^2/3 for the...
Thank you so much! I have been wrong! So, if you have a window in a wall, the design for its fasteners, would be the area of the window? And if I am designing a wall with two shearwalls on each end, then I would use the area of the total wall? Stenbrook, where does the wall squared come from...
Hi, I am new to ASCE 7-05, Eng Tips, and my internship as a structural engineer. I am trying to understand the effective wind area. I am given to understand that it is the area of, say, a wall in which a window is located. So, it is the area of the wall and not the window?
Thanks for helping a...
