Pole Barn questions

[marrt]

I need to put up a pole barn to store my tractor. I have a couple questions as follows:

+ I ordered a nice set of plans. However, the plans have a pole right in the middle of the floor. I don't like that. Anyone know a source for plans with the poles only around the perimeter?

+ What's the "secret" to lining the poles up properly during installation? The last time I tried this, it was endless trial and error.

+ And finally, I believe the professional installers drill the holes, pour a pad in each hole, and set the poles all in one day. How do they get the concrete to set up so fast? Or do they use something else in the bottom of the holes?

Thanks in advance.

 

[shaley]

I can't speak for the center post without knowing the span and truss geometry.
Use batter boards and string for location. Drill a 10" hole for 4x4 for easy position alignment and put gravel in the bottom for wicking moisture away from the post as well as providing a flat bottom. Set the strings up and position the poles and pour in regular sackrete and it will harden in about 3 hours

 

[Gary51]

Marrt-If the poles in the middle or 12' wide from the exterior, you should be able to park a tractor and equipment on either side of the center line. If you just don't want the middle pole, your probably going to have to use trusses depending on the span. I would suggest buying pre-engineered trusses for that and beef up the exterior wall for support of the trusses.
To line up the poles just use the 3,4,5 rule. Set a corner marker stake and pull a string out tight with another string from the same stake at about 90 degrees from it. Measure 3' down the first string. Measure 4' down the second string. Pull a tape measure from the 3' spot to the 4' spot on each string. Move one of the strings until the diagonal measurement is 5'. That will give you a true 90 degree to set your poles to. On a large shed, you can mutiple each measurement to get a longer run. ex: mutilply each by 5 and you get 15',20',25' to get the square.

 

[tommu56]

as gary51 said with the 345 rule but measure out as far as you can like for a 24 x 40 building 24 ft then 32 ft with a diagonal of 40

In the bottom of the holes around here they put a "cookie" in the bottom of the hole a precast concrete disk about 18" in diameter for the post to set on.

tom

 

[SkunkWerX]

I have a 30 x 40 building, no center posts.
Engineered trusses make that happen.

If your diagonal measurments are exactly equal, then you are square.

If we had an idea of the dimensions you were considering, it would be helpful.

 

[Willl]

Or do they use something else in the bottom of the holes?

With mine they tossed 2 bags of concrete in the hole (still in the bags), set the poles on top of the bags and back filled with torpedo sand.

 

[Bill Barrett]

Batter boards to square building.
Put strings up 11/2" out from finish pole point so you don't move the string as you set poles.
Put 2x4 in each direction so you can bump pole plumb. after one or two poles it becomes easy.
I've been told not to use concrete anymore, it reacts with pressure treaded wood, use precast (cookie).
Put a 2x6 in hole to side the pole against, that way you don't scrape dirt in.
If you have a Menards anywhere they have a free book on how to construct a pole building, pretty good.
If you want to see holes and precast cookie check this thread
http://www.tractorbynet.com/forums/attachments/108604-rhino-post-hole-digger-big.html

 

[Brad_Blazer]

Here is what I did. The pics are in reverse order. The poles are in a 16 x 32 pattern with posts/trusses every 8'. The diagonal post braces were placed while setting the trusses to account for variations in post size / placement.

 

[john_bud]

The trick is to mark out the pole locations in advance. Then use your PHD with a 14" or 18" bit to make a large deep straight hole. Put the round paver in the bottom and have one guy hold the pole up with 2 levels, while the other 2 guys shovel in dirt. The 4th guy tamps it down with an 8 or 12# sledge.

You can do it with 1 person, but you have to build some temp braces for each post.

jb

 

[EddieWalker]

Brad,

Real nice looking barn you have there!!! Thanks for sharing.


marrt,

That center post means that the plans are relying on a beam to suppor the load of the roof. You'll probably need some sort of gluelam beam also with that sort of design. I'd return the plans and demand your money back as it's pretty simple to find a set of plans the actualy engineer the design for you and not something like that. You can easily spand 48 feet with engineered trusses and I've built my own for 24 foot spans. If you look around online, there are all sorts of sources that you can copy, depending on how far, roof pitch and what type of eves you will have.

Are you planning on building it yourself? Do you have any experience or knowledge of how to frame a building?

Another option that might work out well is a metal building kit. If you build it yourself, you can really save a fair amount and eliminate all the skills needed to build with wood. Not that building with wood is dificult, but it is time consuming and there are allot of little details that you should know that if you miss them, might lead to problems down the road.

For the posts, I measure them out first. Then check and double check to be sure it's perfectly square. Then I mark out each post and actuall dig it first with a shovel. I've had too many holes go off target when the post auger bit catches something right under the surface, or it just wonders on it's own. Then you have a hole that's not right from the very beginning. With a shallow hole a shovel, or even half a shovel deep, the hole is exactly where you want it, every time.

I have a 12 inch auger and consider it to be the very minimal in size. Your posts are smaller then 12 inches, but it doesn't take very much to be off a bit and it's a real pain ajusting those holes. John is dead on accurate in recomending a larger auger, and I sure wish I had some bigger ones myself!!!

I've heard allot of stories about how to protect the ends of the posts, but in my lifetime, I've never seen a post rot out from the bottom. I do a fair number of fence repairs every year, and it's always right at the surface where the posts rot first and then the rot works its way down. In my opinion, the only place you need to be concerned for your wood posts is at the surface. If you can get water away from there, your posts should last long after you are gone. If not, it doesn't matter what else you do, that's where they will rot.

What are the dimensions of your barn?

Eddie

 

[dweitzel]

Here is what I did. The pics are in reverse order. The poles are in a 16 x 32 pattern with posts/trusses every 8'. The diagonal post braces were placed while setting the trusses to account for variations in post size / placement. /QUOTE]

Brad, what are the dimensions on your barn?

Did you have someone engineer your trusses?

How did you account for snow load/wind in your area? I imagine CO has substantial snow loads to worry about.

I REALLY want to build almost exactly what you have built, but with a span of about 20 - 25' between the sides.

What size dimensional lumber did you use for the trusses?

Thanks for sharing.

Dave

 

[Brad_Blazer]

Dave,
I'm glad you like it.
My barn is 16' x 32' to the center of the outside corner posts. The roof covers about 18' x 36'. I'm actually in NC. I am a mechanical engineer and I designed the trusses around the material I had on hand to provide a solid connection to the post, easy placement, and a good center height considering my relatively short posts. I overdesigned in lieu of rigorous optimization. Note that pole barn trusses are heavy due to the longer spacing compared to a stick built structure where trusses are 24" on center. The main truss elements are nominally 2x10 full dimensional hardwood. The gusset connections feature glue and plenty of nails. The 2x8 dimensional purlins are on joist hangers plus there is a 1x3 hardwood strip nailed & glued across the top of the purlins that ties across the trusses as well as tying in the end overhang extensions. Those strips support the metal roof and made it easier to screw down.

Those are the features of my trusses. I haven't seen others like them. The engineering of your trusses will be your responsibility. You can sketch what you want and bring it to a local engineer or even show pictures of mine and request a similar design.

Hope that helps,
Brad

 

[dweitzel]

Dave,
I'm glad you like it.
My barn is 16' x 32' to the center of the outside corner posts. The roof covers about 18' x 36'. I'm actually in NC. I am a mechanical engineer and I designed the trusses around the material I had on hand to provide a solid connection to the post, easy placement, and a good center height considering my relatively short posts. I overdesigned in lieu of rigorous optimization. Note that pole barn trusses are heavy due to the longer spacing compared to a stick built structure where trusses are 24" on center. The main truss elements are nominally 2x10 full dimensional hardwood. The gusset connections feature glue and plenty of nails. The 2x8 dimensional purlins are on joist hangers plus there is a 1x3 hardwood strip nailed & glued across the top of the purlins that ties across the trusses as well as tying in the end overhang extensions. Those strips support the metal roof and made it easier to screw down.

Those are the features of my trusses. I haven't seen others like them. The engineering of your trusses will be your responsibility. You can sketch what you want and bring it to a local engineer or even show pictures of mine and request a similar design.

Hope that helps,
Brad

Thanks Brad. That gives me a real good idea that I can do this with the proper support from an engineer, and perhaps some of the materials I have on hand. Looks like 25x40' may be obtainable with a little hard work on my part.

Thanks for the reply!

Dave

 

[marrt]

Thanks for the comments guys. I've been so busy that I haven't had a chance to respond. My building will be 30'x36'. I've about decided to just hire someone to put up the super structure at least. I just don't have enough free time to tackle it right now.