The addition of an attached carport will allow you to enter and exit your vehicles from your home while being protected from the weather. It will also provide shade and protection for your vehicles from the harsh sunlight and other elements that cause fading and wear. Building an attached carport yourself is not a complicated project.
Remove the fascia board along the area in which you will be attaching the carport. Look at the fascia header. If it is not at least of a size equal to 2-by-8 lumber or larger, make an additional fascia header. This is done by measuring and cutting a 2-by-8 piece of lumber to a length that is the same size as the side of the carport that will be attached. Use heavy duty 4-inch lag screws and washers to attach the 2-by-8 at each rafter.
Start at one end and fasten joist hangars to the fascia header with wood screws; space them 24 inches apart on centre.
Lay out the area on the ground that the carport will be covering. Mark locations for the support posts. Two posts should be located at the corners of the carport opposite of the attached side, and also every 10 feet in between these two corner posts.
If you are working with a soil area under the carport, dig 18-inch-deep holes at each post location, sink cylindrical concrete forms into the holes to ground level, and fill with concrete. Set and align 4x4 post anchors in the concrete and allow to cure.
If you are building a carport on concrete, use an electric drill and masonry bit to drill holes at the post locations, align surface post anchors over the holes, and attach with expanding concrete bolts.
Measure and cut 4-by-4 posts to a length that will ensure a roof slope from the fascia board to the top of the posts, of a 2-inch drop for every 12 inches. Set 4-by-4 posts in the post anchors and plumb. Temporarily brace the posts with 2-by-4 lumber.
Measure and cut two pieces of 2-by-8 lumber to serve as double headers on either side of the support posts. Drill two 1/2 inch holes in each of the support posts, 2 1/2 inches and 5 inches down from the top. Drill corresponding 1/2 inch holes in the 2-by-8 beams so that the 1/2 inch bolts may be inserted to attach the two headers to the posts.
Raise the headers, with one header to the inside of the posts and one to the outside of the posts. Align the holes, insert the 1/2-inch bolts with washers, and fasten securely.
Hang joist hangars on the inside of the inner header in alignment with the joist hangars on the fascia header, every 24 inches on centre.
Cut joists to a length that is the same as the distance between the fascia header and the inner header. Set the joists in the joist hangars and fasten with wood screws.
Deck the carport by nailing 5/8 inch plywood to the joists. Cover the decking with two layers of 15-pound asphalt paper, overlapping the edges 4 inches, and fastening to the decking with roofing tacks. Add a drip edge to the side of the decking above the support posts. Shingle the roof, paint or stain the lumber to your preference, and your carport is complete.
Shingles should not be used if you decide that you need to have a roof slope of less than what is recommended in step 6. Consider roll out asphalt roofing products for this type of application.