Wind/Weight load question

[Eric Wettschreck]

I've been seriously thinking aboot putting up a pole building for a few years now. I'll be putting it up myself with the help of a few buddies and a lot of beer. Since I'm the tightest hindered guy on the planet I've been doing a lot of shopping around.

I keep running into the same question. What's the wind/weight rating I need? A, B, or C? I'm assuming (assumptions are dangerous) this has something to do with rafter spacing, 9', 8', or 2' on center.

Does anyone know what these load ratings mean? Also, what advantages/disadvantages are there in the different rafter spacing?

Where I live, county and local, there are no code requirements concerning rafter spacing and I'm not only curious, but am trying to get the best bang for the buck.

[BobT]

Rafter spacing, design, material, and assembly practices all play a role. This is where the expertise of a good contractor can be valuable. Be careful about being too penny wise and dollar foolish if you're concerned about quality. Unfortunately, I am not qualified to answer your question so I won't try.

[Eric Wettschreck]

I have no intention on sacrificing quality to save a few bucks. I've always told myself if you're going to do something, do it right the first time.

[chad austin]

How big of a building are you planing on? How far are the trusses going to span? What kind of a roof do you plan on using, tin or shingles?

[Eric Wettschreck]

I'm thinking around 30 something by 60 something. Steel roof.

Don't know about the truss span yet. Not quite sure what the best route to go is.

[huckfin]

Most post frame structures are built with the sidewall pole spacings 7'-6" or 8' spacing. Endwall spacing is generally 10' spacing. Truss spacing the same as pole spacing. 7'-6" spacing the 16' roof girts by pass each other on the truss. 8' spacing you need to alternate 16' and 18' roof girts to by pass on truss. Truss pitch 5/12 is preferrred but the majority still use 4/12. 35# snowload prefered but for the majority of sites 30# will do. 90 MPH is pretty much the standard now for wind load. If the structure may EVER be finished off on the interior you will need a ceiling load designed into the truss load. Some who know that some day down the road they will be finishing will put the trusses 4' on center and still have the post on 8' spacing to eliminate the future need of ceiling girts. If you plan on finishing off you should plan on a truss overhang for ventilation intake. Not an expert just my opinion