A metal pole barn can be one of the most useful structures you'll ever use. Farmers and ranchers store hay under the roof of a pole barn, and RV enthusiasts park their motor homes and campers beneath a pole barn to protect them from the sun's rays. Many homeowners erect a pole barn to use as a carport beside the house. These instructions assume a simple open structure, 12 by 24 feet with a gable roof, built from a prepackaged kit. The pole barn will be anchored to footers and have a dirt floor.
Start by creating a plan for building your pole barn. Check your local building codes before you start this project. In some areas, the local authorities may make you take the pole barn down if you fail to get proper building permits. To decide how you want the barn to face on your land, consider the direction of prevailing winds and sunshine--you'll want to minimise the former and make the most of the latter.
Lay out all the pieces of your pole barn kit and confirm that everything is there. Read the instructions and look over the drawings to make certain you understand the entire project before you start building.
A solid foundation is essential for your pole barn. You need to understand how your soil responds to changes in temperature and moisture, and you need to know something about load limits. You might want to hire a professional to help you with your footings or slab. Bear in mind that you may not want a concrete floor in a hay barn and you can always install a floating slab later. If you're building your barn where the ground freezes, place your footers below the frost line. The simplest method for creating footers and installing your vertical poles is to dig a hole at least 18 inches deep for each pole, set a pole in the hole, and fill the hole with concrete. Use a level to confirm that the pole is vertical.
If you're using precast footer blocks, install vertical poles on your footers using the mounting brackets that came with your kit. These verticals will support your barn's roof, so ensure that they're solid in the ground.
Build the support structure for your pole barn roof. Lay horizontal stringers across the tops of your vertical poles and fasten them with hardware included in the kit.
Build your roof trusses (the triangular structures that create the roof's gable) on the ground, and use scaffolding to get them up to the stringers. You may need extra help with this step, as the trusses can be heavy and the stringers are a long way up there.
Attach purlins (horizontal roofing supports) to the outside of the trusses. You'll screw the metal roofing to the purlins.
Attach your sheet metal roofing to the purlins. Overlap the pieces of metal to create a more watertight roof. You can use caulk between the sheets of metal to seal out the rain and snow. Add a roof cap to keep water from running in through the roof's gable.