A pole barn is one of the cheapest, simplest structures you can build. Pole barns can be used as sheds and garages, for livestock feeding and housing or any other purpose that requires a sturdy structure with a good roof. A pole barn can be any size, from something that just stores a garden tractor and tools to a livestock barn with stalls and a hay loft. It can be built on bare earth or on a concrete floor, covered with wood or metal or with the sides left open. Check local building codes for any regulations before you start.
Prepare your pole barn site and stake out the building. If you're building a backyard shed, a shovel and wheelbarrow may be all you need to level the site. If you're building a 50-foot-long barn, you'll need earthmoving equipment and maybe even a contractor. Once the site is cleared of rocks and debris and is leveled, use stakes and builder's twine to mark your corners. Measure from one back corner to the opposite front corner, and then measure the other side. Place stakes at the spots of your measurements. If these measurements are the same your barn will be square. Outline the perimeter with twine. Mark all of your pole locations. For a simple shed you will probably only need to mark four corners; for a larger barn you will need to mark the corner posts and other posts (generally set 8 to 12 feet apart), plus center posts for roofing.
Set your poles by setting the corner posts first. How deep and how big your post holes will be depend on size — a shed will need holes only a couple of feet deep and not much wider than your poles; a big barn will require holes 4 feet or more deep and ideally wide enough to accommodate "uplift cleats" (wood strips nailed horizontally to help hold the pole in the ground). Place your posts and fill the holes with concrete. To keep the poles plumb and square, nail temporary support boards to the poles and stakes outside the perimeter. Your center posts will have to be longer to accommodate roofing.
Frame your pole barn. Start by nailing skirt boards perfectly level around the bottom edges of your poles, and then install beams across the tops of your poles. How you finish framing will depend on what sort of walls, if any, you will use. For a walled shed or barn, you may want to consider 2 by 4 framing, much like studs on a house, which then could be covered with planks or sheathing. For an open structure, place enough horizontal 2 by 4's to brace the poles (if you are using metal siding, nail these boards where you will need to fasten the siding panels).
Roof your pole barn. Again, there are options, depending on size and use. You can set prebuilt roof trusses on top of the beams or form your own roof. Build your own roof by nailing cross-members from side post to side post, across the center post, and then roof supports from side post to the higher center post. With either option, cover the roof with metal roofing panels; you can also deck the roof with plywood or oriented strand board, and then finish it with shingles, but this will be much heavier and require more post support.
Finish your floor. A poured concrete floor will be most durable, but a basic shed or livestock barn may be fine with a dirt floor. To pour a concrete floor, build forms around the perimeter of your pole barn, generally, 2 by 4 or 2 by 6 lumber staked in place. Lay wire mesh or other reinforcement, and then pour concrete to finish the floor.
Things You'll Need
Post hole digger or auger
Saw (circular or reciprocal)
Be sure to check building codes; many areas have restrictions on outbuildings or regulations governing structural elements.
Check for underground utilities and overhead lines before selecting your site.