This was a 15ft porch roof held up with a 4×4 on each end painted white, badly faded and in need of a redo.
I installed another 4×4 on the other side of the steps. Then i cut the long curve upper piece by using a stake and a wire. I rolled out the wire until i could put a pencil on the end of the wire at the center of the board where i wanted it cut. Then i cheked both ends and moved the board closer to the stake, readjusted a few times until the pencil touched the bottom of both ends and was 3″ from the top in the middle of the board. Yep alot of work adjusting anf checking before i drew the line. Then i cut it with a circular saw and sanded it smooth with a belt sander.
Then i nailed one in place. Next to wrap the posts. I did the inside sides of one side of each posts with 1×6 treated wood then i marked and cut the 1×8 front boards under the arch. cut and sanded for a great fit. Its okay if there is a gap at the botttom because it will get wrapped with a 1×4 at the end.
Once the front and the insides are wrapped then install the upper inside arch before cutting the last piece of each 1×8 under that arch. After that all thats left is cutting the 1x4s to wrap the bottom. I cut a 45 degree angle on each end of each piece.
I will let the wood dry out good for at least a week before caulking all seams and painting on several coats of white exterior paint.