ASCE 7-05 FOR WIND

[m1208]

For one story hour with a roof mean height of 15', gable end wall system, roof pitch 4:12, wind 85 mph, exposure C, I am getting 32 psf wind uplift for the roof ridge beam. I need this load for the code load combination system to design the ridge beam. Any body has any idea why the uplift wind is so high. Would Fig 6-2 apply or Fig 6-3? The reason I am asking the tributary roof area for the beam is more than 100 sq. ft and Fig 6-3 does not have values over 100 sq. ft. Are there any detailed design example calculations on line?

 

[ajh1]

If you look at Figure 6-11C for Method 2 you'll see that components and cladding factors for any effective area over 100 sqft are the same, so use the 100 sqft value. Areas over 700 sqft can generally you the MWFRS values, i.e. Figure 6-2.

 

[XR250]

I usually ignore ridge uplift. The same folded plate mechanisms that keep a vaulted roof from TEMPORARILY spreading out if no structural ridge beam is installed are at work keeping the ridge from picking up (for the short duration) as long as the rafters are tied down to the perimeter walls.

 

[Ron]

m1208....This is essentially the same question you asked in your previous post. Please don't double post. It is against forum rules.