Pole Barn - Why not use center post?

[LD1]

LD1,
You are correct on all spects of your reply. Did not want to keep saying "I did not say this or that" anymore. I do intend to use metal roofing.

I was thinking the mains would either be 2x10 or 2x12 and 2x8 purlins. I agree I need to get a little more info and that was the point of the post. Thanks for the reply.

Just at first glance, I dont think 2x10 or even a single 2x12 will be enough for the mains. Pitch doesnt matter. You look at the horizontal span. Which will be 15' in your case if you are going 30' deep.

So basically you need to look at this like a floor, with the "main rafters" being the beams, and the horizontal purlins being the floor joists.

I am not sure what you need for "beams", and I am not sure how far appart they will be, But again, just at first glance, if 2x8's every 2' are needed for the purlins, I think something a bit stouter than even a single 2x12 is needed.

Just rambling here but see if you can follow....If you plan on spacing them 10' appart, Each beam will have to hold up 150 sq ft of roof. (5' each side which is 10' x 15' deapth to ridge beam). This is figured in a horizontal plane.

Now probabally the lowest code an engineer would let you get away with would be a 5psf dead load and a 20psf live load. Total of 25 lbs per sq foot. So, 25x150 is 3750 lbs evenly distributed that must be supported by EACH "beam" or "Main Rafter" AND span the 15'. This is the area I suggest to contact a PE for approval. And definatally as already mentioned, check to see if there is any laws or codes you MUST follow for your area.

Sizing the purlins is simple.

And one other thing you might want to check on... I am not sure where in GA you live, but I bet you get some wind. So think about your attachment points. With the method of building you picture, their are fewer attachments points holding the roof structure to the walls.

 

[gabeancounter]

LD1,
I follow your logic. It appeared to me in the picture I posted that the board size for the purlins was 2x6. The mains look around 2x8 or 2x10. I thought I was using overkill by 2x8 purlins and 2x10 or 2x12 mains.

I figured I could get some input to this method on this site before spending $15 on the download for the "secerts". But if the board spacing and sizing is that far off , then it will cost as much as using trusses.

 

[gabeancounter]

This is one of the few that seems to be using a similar build design. Now his spacing is around 12' I think. My design was similar just not the center section. This is steeldust photo from his thread.

 

[LD1]

This is one of the few that seems to be using a similar build design. Now his spacing is around 12' I think. My design was similar just not the center section. This is steeldust photo from his thread.

It looks like you are close with the spacing @ around 12', BUT, it doesnt look anywhere near a 15' span though. It looks like maybe 10' at the most.

AND it is hard to tell, but it looks like the middle sections are a DOUBLE 2x12. See pic.

The middle two "beams" will have to support twice the load as the end beams. Because they have to support the roof on BOTH sides half way to the next beam. The end beams only are supporting roof on the one side, not counting a small overhang.

 

[gabeancounter]

Off topic. I just noticed that it looks like his kid is laying in a stroller while he is working on his barn?? Too funny.


Not sure about his spacing, but it looks very sturdy. I think I will re-read your thread as I found out over the weekend that I think the covenants will require it be enclosed. How much did you have invested in your build?

 

[LD1]

Off topic. I just noticed that it looks like his kid is laying in a stroller while he is working on his barn?? Too funny.


Not sure about his spacing, but it looks very sturdy. I think I will re-read your thread as I found out over the weekend that I think the covenants will require it be enclosed. How much did you have invested in your build?

I just noticed the stroller too:laughing::laughing::laughing: Maybe the horses were watching the little one:thumbsup:

To answer your question, I have probabally ~$10k invested. That is as current with: electrical, concrete, loft, insulation, etc.

Since I used electric poles, that saved a ton on cost. But JUST the basic framing material I bought to get the trusses up and the walls built was ~ $1000. Metal was the expensive part. I cant remember off the top of my head, but it is around $3k in metal. So I was at ~$4k to get it under roof. That was nothing extra, no doors, and just open on one side.

 

[JimRB]

If HD/Lowes does not have the lumber you need sitting in their racks what do you do? I wanted 2x8 20' long. Lumber yard had it. I wanted 16' and 20' 6x6. Lumber yard delivered it at a good price. I am about as cheap as many others and would not be going to a lumber yard to pay more. But I do sometimes place a value on my time. At least the counter help at the lumber yard knows what I am asking for. Of course some of the guys at Lowes and HD know their stuff too.

Here is one thought to the original poster. A greater/longer overhang on all sides can reduce the amount of splashing on the exterior walls. If you have open sides it might reduce some of the water that blows in although with our storms I have seen water blow in 10 feet when our 10' tall doors are left open.

 

[Johnbro]

Green,
I don't need a crew of engineers to build a dang pole barn.

LOL. well said.

I think trusses are MUCH easier than rafters. I made my own trusses for a wood shed, and the next time I'll just buy the suckers. I made a jig on the floor to hold the pieces (which were all pre cut on my chopsaw), then glued and nailed plywood gussets down to hold everything in place. I would have used those metal pound plates, but the ones at the local HD said clearly "Not for trusses." so I didn't. Besides, I'm cheap:laughing:

Cutting rafters isn't rocket science, but there are at least 3 or 4 ways to screw it up and then what do you have? A bunch of 2X lumber that's too short. Plus, maybe your lumber is better than our lumber, but even when I buy 16 foot 2x8 or 2x10s from teh GOOD lumber yard (Dunn Lumber) finding enough that are nice and straight is tough. And placing them is a pain compared to trusses--the only thing important placing trusses is to get them aligned top and bottom--mark off your top plates at 24"OC or whatever your spacing is. Then take some 1x4 and mark it exactly the same. Use the 1x4 as a temporary support nailed along the top sides of the trusses to hold them vertical until you can put sheathing down.

With rafters, you sort of have to use collar ties to keep the downward pressure of the roof from spreading the sides of your building apart. So now you've got three pieces of wood (two rafters and a collar tie). Might as well buy trusses!

 

[gabeancounter]

Johnbro,

I agree. But looking at that framing picture it sure does look easier and cheaper than building with trusses. I think I maybe converted to trusses, now the diy or store version is in the air.

Jim,
I understand all to well about lumber yards. I have an account with Social Circle Ace and 2 years ago when I was building my house I purchased around $100k of products from them. Everyday pricing will have many of the yards cheaper than HD, but on certain items like when OSB goes on sale or when you have 10% coupons and can get 2x8x16 for $7.25 the yards can't match it.
Now as far as quality of lumber, I have not seen any better lumber from the yards compared to big box. You are correct in the quality of service and ease of delivery. I pay $5 for delivery no matter if it is a single board or a tractor trailer load and it is always same day if ordered that morning.
I assume you used Plymart on Alcovy or 84 lumber on 278 since they are now "out of business". I tried both of those yards and the economy had already taken its toll on them long before they shutdown.

 

[JimRB]

Johnbro,

I agree. But looking at that framing picture it sure does look easier and cheaper than building with trusses. I think I maybe converted to trusses, now the diy or store version is in the air.

Jim,
I understand all to well about lumber yards. I have an account with Social Circle Ace and 2 years ago when I was building my house I purchased around $100k of products from them. Everyday pricing will have many of the yards cheaper than HD, but on certain items like when OSB goes on sale or when you have 10% coupons and can get 2x8x16 for $7.25 the yards can't match it.
Now as far as quality of lumber, I have not seen any better lumber from the yards compared to big box. You are correct in the quality of service and ease of delivery. I pay $5 for delivery no matter if it is a single board or a tractor trailer load and it is always same day if ordered that morning.
I assume you used Plymart on Alcovy or 84 lumber on 278 since they are now "out of business". I tried both of those yards and the economy had already taken its toll on them long before they shutdown.

Covington Plymart for house, Covington 84 for a shed, some other yard in Lithonia for the barn. All three lumber yards are gone. I did send back a fair bit of cull. When building the house I spent 2 days pulling crummy studs out of the house after the framers left. Actually more like two man days as some friends helped me do the framing cleanup. Yes all sources have some crummy lumber that may need to be culled. I did use HD in Conyers for lots of stuff as there was no HD in Covington. Social Circle Ace seems like a good yard which would be on my list if I was doing another big project. I hope I can build a new tractor shed in 5 years but I have bills to pay now.

My wife has code in her web page to kill linking to this page but if you cut and paste you can read the silly tale of me building my pole barn for horses. Pole Barn Building I did another pole barn with my barn electrician as a labor swap. Instead of getting the poles 1/2" out corner to corner I got that second pole barn dead on. We did trusses for a huge clear span on the electrician's barn. He called a light bucket truck friend to help set those trusses. Pole building can be fun but next shed is going to be stick built on a concrete pad or maybe metal framed depending on which material makes the most sense price wise.