New Build pending, questions first

[pr1me]

Hey all, long time lurker here. Registered because as much reading as I've done here, I still have questions.

24x36 pole barn, was looking at 6x6 posts, 12' OC.
Here in Southwest Louisiana we don't get much snow, does this spacing seem adequate?

12' eaves, want an 8' deep mezzanine along the gable end. Hoping to do 6/12 outside, 4/12 inside scissor trusses so I'm able to stand up on it (waiting to hear back from truss mfr). Will be using it to hold a small desk and computer, plotter, vinyl cutter, and my 155# self, no storage or engine blocks. I'm okay with using posts to support the 24' span, but what size joists? 2x10 with 6x6 supports every 8'? 16" OC?
Should they rest on top of the slab or be cemented in like the posts?

Planning on bookshelf girts, notching the headers into the exterior of the posts. Header size, 2x10? One sitting in the notch, one bolted to interior face of post?
Preferred attachment method? Saw suggestions about nailing in place, then using 1/2" bolts. Carriage? Lag? All thread with washers and lock nuts?

Only code restrictions in my area (according to permit office) are that I can't build closer than 3' from property lines in the rear, walls no higher than 16', no larger than 2000 sq ft for my property size, and a few other odds and ends that are common sense. Other than that they just said don't build something that will become shrapnel in a hurricane, as if I were considering it lol.

Thanks in advance for any help!

 

[OneOfEm]

My plans are at the engineer at the moment, but his "standard" design for a 24' wide pole building (12/4 pitch, if that matters) specifies 6x6 posts 12' OC with an 18" diameter x 36" footer with 6 pieces of #5 rebar running through the bottom of the post to lock it to the footer. Mine will use steel trusses, so I can't help with your other questions. This is in NW FL drawn to code for 140MPH wind load.

Strangely enough, he seems to be struggling with the concept of bookshelf girts. I'm waiting to see what revision 2 will bring.

 

[pr1me]

My plans are at the engineer at the moment, but his "standard" design for a 24' wide pole building (12/4 pitch, if that matters) specifies 6x6 posts 12' OC with an 18" diameter x 36" footer with 6 pieces of #5 rebar running through the bottom of the post to lock it to the footer. Mine will use steel trusses, so I can't help with your other questions. This is in NW FL drawn to code for 140MPH wind load.

Strangely enough, he seems to be struggling with the concept of bookshelf girts. I'm waiting to see what revision 2 will bring.

I wonder why the bookshelf girts is messing with him, seems simple enough. Maybe call them 'commercial girts' and see if he feels better about the terminology lol.

Does the footing spec'd go under the pole, with additional concrete around the post itself? Or does the footing include the post being encased?

 

[tinysparky]

for the 12' trusses....the answer is it could work for you.

My engineered trusses are 2 trusses (sandwiched around a 6x6 post) on 12'. with 2x6 purlins. Your truss company should be able to tell you. i paid 1200 to alliance engineering to do my building (county requirement....plus it is a good idea). I believe they cover your state as well. my building plan was for a 40x72.

 

[rayra]

Would it be any help in a severe storm / hurricane to have posts on 6' or 8' centers, instead. Or does it all blow away regardless?

 

[My Old Tools]

I don't know that I would want post in the ground in Lake Charles. Lot's of rain, high ground water, potential for hurricane force winds. Post may rot sooner, ground maynot provide good support when saturated, etc. Just stuff to think about. Talk to an engineer.

 

[MagKarl]

If you want interior headroom you could frame the roof with pole barn trusses and purlins instead of scissor trusses. Mine has trusses and posts on 12 foot centers with 2x8 purlins.

I got my plans and material package here http://www.hansenpolebuildings.com/

 

[larry_g]

I have a similar building (link below) to what you are proposing. My old 30x36 was similar. 12' post pitch is common here. I designed in my loft to align with the post so it is 12' deep and left out one set of trusses and framed it with rafters and two additional posts in the building. My purpose for the loft was not so much the loft but the machine shop under it. Think of where your stairs are going as they can take up a lot of space on both floors.

Also notice that I have a combination of commercial and flat girts. If you use a 2x8 forthe commercial girt then you get 1 1/2" overhang on the outside to allow the metal to go over the rafters and skirt board without notching the poles. Or you can offset the commercial 2x6 girt 1 1/2" to work also.

lg
no neat sig line

 

[pr1me]

I don't know that I would want post in the ground in Lake Charles. Lot's of rain, high ground water, potential for hurricane force winds. Post may rot sooner, ground maynot provide good support when saturated, etc. Just stuff to think about. Talk to an engineer.

Mallett buildings and several others have no issues with any of that, so I don't think it will be an issue for me. Have seen at least 30 pole barn style structures over the last 4 or 5 years, only those without concrete footings or properly sized lumber are in disrepair. Thanks though, good idea on bringing it up!

If you want interior headroom you could frame the roof with pole barn trusses and purlins instead of scissor trusses. Mine has trusses and posts on 12 foot centers with 2x8 purlins.

I got my plans and material package here http://www.hansenpolebuildings.com/

That's exactly what I switched gears to last night. Was trying to design rafters with cross ties above the loft and using a ridge beam for the entire long span but hesitant to fuss with LVL, etc. Don't want ceiling joists so I can take advantage of the additional headroom in the entire place.
Was sort of wondering if pole barn style walls would be prone to the same 'spreading' that stick built buildings are without ceiling joists. Any idea?

Love Hansen since I've discovered them. Have been reading their website like it's gospel lol.

I have a similar building (link below) to what you are proposing. My old 30x36 was similar. 12' post pitch is common here. I designed in my loft to align with the post so it is 12' deep and left out one set of trusses and framed it with rafters and two additional posts in the building. My purpose for the loft was not so much the loft but the machine shop under it. Think of where your stairs are going as they can take up a lot of space on both floors.

Also notice that I have a combination of commercial and flat girts. If you use a 2x8 forthe commercial girt then you get 1 1/2" overhang on the outside to allow the metal to go over the rafters and skirt board without notching the poles. Or you can offset the commercial 2x6 girt 1 1/2" to work also.

lg
no neat sig line

hmm, perhaps I misunderstand the sizing of commercial girts. Wouldn't I be able to use 2x6s so that it lays out flush with the beams?
Was planning on skirt boards also being the forms for the concrete, and doing them strongback style: one flat along the bottom of the concrete, another pair 90* to that up and down, flush with the outside face of the poles. Bottom is form for concrete, top is skirt board to attach sheeting. No notching poles except for the top, which I want to do anyway so that the load is not only on the fasteners.
Can I do it this way?
Any reason to use 2x8 other than no notching?

 

[larry_g]

hmm, perhaps I misunderstand the sizing of commercial girts. Wouldn't I be able to use 2x6s so that it lays out flush with the beams?
Was planning on skirt boards also being the forms for the concrete, and doing them strongback style: one flat along the bottom of the concrete, another pair 90* to that up and down, flush with the outside face of the poles. Bottom is form for concrete, top is skirt board to attach sheeting. No notching poles except for the top, which I want to do anyway so that the load is not only on the fasteners.
Can I do it this way?
Any reason to use 2x8 other than no notching?

I recommended 2x8" commercials IF you want the sheathing to run over the skirt board and the top rafter/truss if if they are on the outside of the posts. If you flush the girts and everything with the outside of the posts then 2x6 is the correct material.

My skirt board is also the form board for the concrete. It is on the outside of the posts as are all the flat girts. There are a few different ways to do this, it's just how I did it. As for notching the posts for the trusses my engineer had me BOLT on a 3-4' 2x6 on the post and set the truss on that. If you do the double truss like I did then everything fits for the spacers between the trusses and the blocking between them.

lg
no neat sig line

 

[pr1me]

I recommended 2x8" commercials IF you want the sheathing to run over the skirt board and the top rafter/truss if if they are on the outside of the posts. If you flush the girts and everything with the outside of the posts then 2x6 is the correct material.

My skirt board is also the form board for the concrete. It is on the outside of the posts as are all the flat girts. There are a few different ways to do this, it's just how I did it. As for notching the posts for the trusses my engineer had me BOLT on a 3-4' 2x6 on the post and set the truss on that. If you do the double truss like I did then everything fits for the spacers between the trusses and the blocking between them.

lg
no neat sig line

Perfect, that's exactly what I planned to do. Flush everything with outside of posts.
I wasn't planning on notching for trusses, only the outside truss carriers/headers (depending on your vernacular). 2x10s work for this? Was planning on rafters, but need to figure out what size for the ridge beam, if required. Not sure if pole barns are susceptible to the same spreading forces stick built walls are.

Also, wife just suggested I go full 2 story instead of loft. I wonder how I'd get 24' clear span, floor trusses? I beams?

 

[pr1me]

Designed it pole barn style, came out with x materials list.
Designing it stick style, will have y material list.
I will shop both lists around and compare, but builder thinks stick built will be cheaper based on wall height, though he's done it both ways.
Trust the guy, has done a lot of work for me in the past so I know his word is gold, but obviously i'll follow the money for the value.

Only questions remaining I have;
Rafter + purlin option; spacing of rafters? Was thinking 8' oc but no idea if I can/should space them out like trusses would be. Also, how do I find out what size ridge beam I'd need to support the rafters? Can't seem to find span tables for beams and LVL stuff.

Stick built; balloon or platform framing? Worried balloon framing will be harder to keep square because I always find that the longer the board, the harder it is to find square and plumb ones. But worried platform won't be as strong because the rafters would press outward and make the meeting of the pony walls and their bottoms a hinge point? May be overthinking that one. Or even underthinking.

Wife's suggestion of a full second floor may change plans. Originally I was going with 12' walls and a short mezzanine so that I still had full height before the mezzanine, but full second floor would limit ceiling height. Would likely raise second floor height to at least 10', meaning 16' walls and likely 3/10 rafters for headroom.
Any obvious issues with this?

If not, I'm back to the clear span question again; 24' clear span I assume only I joists or floor trusses would remotely make it. Correct?

Sorry for the novel, just trying to be concise.