How to Make a Pole Barn Garage

Select a building site. The site for a garage should be flat, with easy access to your driveway. Lay out the dimensions your building will require and mark each corner of the building. If possible, your door opening should face south. Mark where you have planned the door opening. Check the soil composition on your building site. In general, sandy and gravelly soils are better for pole buildings than clay-rich soils.

Dig a 3-foot-deep test hole near each corner of your planned building. Record the depth and types of top soil, subsoil and substratum layers. The subsoil layer is most critical. Obtain building permits, electrical permits and plumbing permits. Check that your building conforms to local zoning and lot setback requirements. Ask your local building officials for pole embedding depth requirements for the soil at your site.

Lay out the exact building lines with a tape measure. Set batter boards in the ground at each corner. Place the boards 4 feet back from the corners and stretch a string tightly between the boards. The strings will locate the corner and side post holes and will ensure correct post alignment.

Square up the string layout by measuring from left front corner to right rear corner, and from right front corner to left rear corner. If the measurements are identical, the building is square.

Set the posts. Dig a hole 4 1/2-feet deep at each corner. Fill the bottom with a 6-inch-thick concrete footer. Use 4-by-6-inch pressure-treated posts that are installed so the wider side is perpendicular to the line of the wall. Set posts in the hole and use temporary 2-by-4-inch braces to hold the posts plumb.

Backfill with dirt and tamp the dirt tightly with a soil compactor. Dig holes and install side wall posts between the corner posts, bracing them so they are plumb. Space poles 10 feet apart or use the spacing specified in your building plans.

Nail a 2-by-8-inch skirt board around the bottom of the posts at grade level, with the wide side parallel to the line of the walls. Install the board so it is level all around. Nail up 2-by-6-inch girt boards around all the walls with the wide side parallel to the line of the wall. Leave an open space for your door.

Install three girt boards spaced evenly up the walls. Nail a 2-by-8 header over the top of the door opening. Cut a 1 1/2-inch notch in the top of the posts parallel to the line of the wall. Set twinned 2-by-12-inch boards on the notches and bolt the boards to the posts with 1/2-inch carriage bolts.

Assemble roof trusses from 2-by-6-inch lumber and rafter tie plates according to your building plans. You will need one truss for each end of the building and one for each 4 feet of wall length.

Cut a notch 1 1/2 inches deep at the top of each wall post. Set a truss into the notches and secure it with 1/2-inch carriage bolts. Set trusses in between the post trusses and secure with metal truss hangers. Install temporary bracing to keep the end trusses plumb.

Connect the trusses with purlins, or horizontal roof supports, laid flat and parallel with the line of the wall. Space them every 2 feet or as specified in your building plan. Install cross bracing to reinforce the three trusses at each end of the building.

Buy metal roof and wall panels in the size specified in your building plan. Nail the metal roof panels to the purlins, and the metal wall panels to the girt boards in the order specified in your plans. Pour gravel or concrete to form the garage floor. Frame and install the garage door as directed by the door manufacturer.