If there is not enough room in your garage for that new car or fishing boat you just bought, build a carport. Constructing a carport is easy enough that you can do it in a few days and get your new purchase under cover before the rain comes. Building a carport is easier than building a new garage or adding on to an existing garage because there are no walls.
Plan - Before you can begin to construct your carport, you need to check to make sure that you aren’t breaking any local building codes. Also, make sure that the spot you plan to put the carport doesn’t interfere with any gas or water lines or sewer pipes. Mark out the carport using string and stakes. Once you have plotted out the carport, double check to make sure it is square by measuring your diagonals.
Set Posts - Dig post holes at least 1 foot wide and 1 foot deep. Following the manufacturer’s instructions, mix the concrete and pour into the holes and then set a stirrup bracket in the center of each of the concrete pads. You will need a minimum of 3 inches of clearance between the ground and the bottom of each post. Make sure the brackets are level. Place a piece of plywood over the concrete. Allow two days for the concrete to dry. Cut 2 inch X 6 inch notches (rebates) in the top of each post for the bearers. Place the posts in the brackets, checking to make sure that they are perfectly vertical. If the posts are wobbly, you can use stones or wooden braces to support then while you work. Drill holes for the carriage bolts and secure the posts to the brackets.
Plan Roof - Using a string line, measure out the height that you want the roof to be, cutting any excess post. To prevent the roof from gathering water, you should have a slight angle to it, allowing it to slope away from your house so that snow and water can run off.
Bearing Beams - Cut a bearing beam to fit the length of your car port and set it into the rebates you’ve cut. Bolt the beam to the rebates with galvanized 4 ½ inch coach bolts. If attaching the carport to your house, measure and cut another bearing beam and, making sure that it is parallel to the first bearing beam, attach to the side of your house. For a wooden wall, use coach screws. If the wall is made of masonry, dynabolts are best.
Rafters - Following your local building code for carports, measure and cut the appropriate number of rafters and attach then between the two bearing beam with joist hangers, spacing them apart approximately every three feet. Attach the rafters to the beams using galvanized nails.
Attach the roof - Once you have measured and cut your roof, attach it to the top of both the bearers and the rafters. Make sure that the roof screws are fitted with rubber washers. You will also want to make sure that your carport roof extends several inches beyond the frame for rain and snow run off.