Pole barn plan - sanity check

[ejb]

>>All the pole barns that we have built have been on 8' centers with the same for trusses.

I was wondering the same thing to...trusses are about 30% of my cost so far with a metal roof...every place I go to get a price on trusses they tell me I need them 2'oc...but even the morton building that I had a bid done on it was 8'oc I am pretty sure...I just assumed it was some sort of special engineered truss that I didn't have access to as a retail customer...but now I am wondering.

12'oc on the posts is do-able around here, requires a double 2x12 header to support the trusses/roof...but I'll run another calc using 8'oc instead and see how much extra it costs.

I like the idea of having 12 foot wide openings though.

Anyone know about using 8'oc trusses in New England?

 

[ejb]

>> I think a larger & thicker pad for the posts would be good. I've seen a 16" x 16" pre-cast block sold for that purpose, I think it was 12" thick. I have a neighbor that designs barns & I could check if you want.


I am starting to think about the pre-cast idea..especially now since the temp is dropping below freezing at night. I could either make up the blocks and let them setup in the (warm) garage or else buy them ready to go...but is just digging down, and placing a footer as good as pouring a footer? Seems to me a poured footer would be well formed to the uneven ground underneath and would automatically level, whereas a pre-cast one may or may not be nice and level??

About your neighbor, sure, the more info the better.

Thanks.

 

[cowboydoc]

I would call the building inspector if you have to have one and see what he says. If you don't have to have one I would definitely do it that. I can't imagine that you have more snow there than we do.

 

[fishman]

I've run into the same thing here in Texas, of all places. The truss manufacturer doesn't even want to talk about truss spacing greater than 2'. The one time I got a quote for trusses spaced 2' vs. 3' from the same maker, the price difference was about 25% cheaper for the 3', even though stouter lumber was specced. We don't have snow loads here obviously, and I find it ridiculous that trusses alone would be 20%+ of my building costs. I'm seriously considering finding a good book on the subject and building my own. Looks like with a good miter saw, screwgun, structural lumber, plywood gussets, and wood glue you are in business.

As an aside, my dad had a nice 30x40 garage built at his home in Missouri a few years back by the recognized best builders in the area. His trusses are on 10' centers, with a steel roof and that plastic pole barn type insulation. No problems at all, even with some fairly heavy snow and/or ice accumulations. They aren't anything special. 30' span with 2x4's (may be 2x6's) on the top, 2x10's on the bottom, and 2x4 webs, assembled with nailing plates.

 

[shvl73]

I was off on the pre-cast block size, it's 12" x 16" x 8" thick. I was told the 2x10 face-nailed beam capped with 2x10 is how they usually sell them in Mass. They also use a 4' 2x6 for angle braces from post to between 2x10's for bracing. The posts 12' on center were confirmed by him as well. He mentioned in some of NH a triple 2x10 beam is required for snow loads. I would think all would need to be confirmed by local building dept.