To install a shed carport, prepare the ground, set up posts, secure crossbeams over the posts, install rafters, and fasten plywood boards onto the rafters. Apply caulk along the seams of the boards, and mount shingles on top of them.
Before you build a shed carport, contact your local authorities to know proper code specifications and obtain the necessary permits. Determine the size of the carport, measure the ground, and use the measurements to make an outline. Dig six holes that are at least 2 feet deep along the outline. Set 11-foot posts in three holes that are closest to the house and 9-foot posts in the remaining holes. Put concrete in the holes to secure the posts in place.
Nail crossbeams to the posts. Place a rafter on the top of one side beam, use a pencil to designate the point where the rafter touches the beam, and make a 1/3-inch notch at the point with a circular saw. Angle nails through the side of the rafter to secure the rafter in place. Repeat this step for other rafters.
Set at least 1/2-inch plywood roof boards over the rafters, generously allowing for overhang on the front and back of the carport. Fasten weather sheeting over the boards, and shingle the roof. Attach metal braces on the joints and leg supports to increase stability of the carport.