How to Build a Carport Canopy

Mark with chalk a line measuring 18 feet 4 inches across the side of the building you want to fit your carport canopy. The line should be horizontal and 8 feet above the ground.

Saw some 2-by-2-inch lumber to 18 feet 4 inches in length to match your line. If you don't have a section long enough two half-sized sections will do. Drill eight equally spaced holes along the wood. Mount the lumber along the chalk line and use hammer fixings to secure it to the wall to make a batten. Hammer the fixings through the holes you drilled in the batten into the wall.

Cut two sections of 2-by-4-inch lumber to 18 feet and two sections to 7 feet. These will be used to make the side frame of your carport canopy. Place the 18-foot sections parallel on the ground with the 7-foot sections at either end to form a rectangle. These will be the upright supports of the frame.

Screw the 7-foot sections into the ends of the 18-foot sections.

Cut a section of 2-by-4-inch lumber to 6 feet 8 inches to make a third upright for your frame. Place the new upright in the middle of rectangular frame, between the two upright sections. It should connect with the two horizontal sections. Screw it in place from the outside.

Strengthen your side frame by sawing 10 16-inch supports from 2-by-4 lumber, angled 45 degrees at either end so each section resembles a trapezium.

Place one of the 16-inch supports at each of the eight internal right angles of your frame and screw them in place. You may need to drill a pilot hole into the wood to help you. You should have two support sections left over.

Saw two 7-foot sections of 2-by-4 lumber to make beams for your canopy to rest on. Saw or plane off a 10-degree section from one of the ends of each beam so that when you mount the beams against the wall the beam will be angled to allow for water to run off. Place the planed end of one of the beams against the wall, next to the batten you have already mounted. Screw it into the end of the wall-mounted batten so that it extends away from the wall at a slight downwards angle. Screw the second beam into the other end of the batten in the same way. Make sure they both are slightly loose to allow for some play, but not so loose they fall off. You may need a friend to hold them in place temporarily.

Stand your side frame up parallel to your wall so that the two uprights at either end meet the joists. Screw through the joists into the uprights at either end of the frame. Now tighten up the loose screws at the other end of the beams.

Strengthen the frame with the two spare supports. At one end, place the support's 45-degree face on the underside of the beam so that the other end sits alongside the side frame's upright. Screw it in place to the beam and the upright. Do this again at the other end of the carport frame.

Place a 7-foot sheet of clear plastic corrugated roofing over one of the beams of your carport to form a canopy. Position it so that one side runs along the beam, the top of it sits over the batten and the bottom of it is over the side frame. Screw through the plastic into the batten and side frame to fix the top and the bottom in place. Now screw along the side that is sitting over the beam.

Add a new sheet of clear plastic corrugated roofing so that it overlaps the first. It should overlap the first by three corrugations. Screw this in place to the batten at the top and the side frame at the bottom. Make sure at least one screw penetrates the overlapping section of roof sheet to fix both together securely. Continue to add roof sheets over one another until you reach the other beam, when your canopy will be complete. When you get to the final sheet remember to screw along the side into the second beam.

Cover the lumber of your carport with weatherproofing to improve the durability of the frame. There are many types available that you can paint the surface of the wood with.