Considering wind uplift on posts

[BayPointArchitect]

I am looking at a 234 s.f. covered porch supported along one edge that is 18 linear feet against the new addition. But then there are two large 6 x 6 posts supporting the two outside corners. Without any formal training in wind load calculations, I am guessing that the uplift on each post or column is only 1,462 lbs. But this would be even less if I can subtract the dead weight of the roof.

I am not too concerned considering how I have these two posts anchored to large concrete pier foundations. Not to mention the reaction that I received today when I showed the sketch to a structural engineer that would suggest a design that is over-done. He suggested that I could reduce a few measures.

Is it standard practice to subtract the dead weight of the roof from the force of the wind acting upward?

Thanks!

 

[Architect1281]

Here is one of those documents that supplies a dangerous amount of knowledge to those untrained in its specific application.

when calculating uplift gracity is a negative number

http://www.awc.org/pdf/wfcm2001workbookandappendix.pdf

If truly capable buy and download the WFCM http://www.awc.org/standards/wfcm.html

 

[TimNY]

Great link arch.. They also have design guidebooks for xxxMPH Wind Zones that are useful.

 

[Phil]

There is an ASD load combination with 0.6D + W (LRFD equivelent is 0.9D +1.6W).So, 60% of the dead load can be used to resist the wind uplift.

 

[ICE]

If I knew what Phil said I would: Ditto what Phil said.

 

[BayPointArchitect]

Awesome. Thanks everyone.