Locate the ledger first. The ledger is the 2-by-6 to be nailed into place first. It will run the width of the patio, and the patio roof is attached to it. Locate it just below the eaves (overhang) of the house, if the house is single story. Find the band joist and attach it there, if the house is two or more stories. (The band joist/rim joist is the 2-by-6 or bigger that separates the floors of a two or more story house.)
Remove the siding, down to the sheathing, to expose enough area to screw or bolt in the 2-by-6 ledger to the side of the house. (Note: If the siding is fairly flat, attach straight through it without removing it. Always remove clapboard, beveled wood, aluminum and vinyl siding.) Use an inverted piece of beveled horizontal siding (creating a flat surface to attach to) if that is what you have on the house.
Screw the ledger in place to hold it while you attach it more solidly with bolts, washers and nuts. Check for level as you insert the screws. Ideally, attach the ledger by pre-drilling holes and running bolts through the ledger, the sheathing and rim joist and attaching nuts and washers from inside. If inside wall access is blocked, plan to use ½-inch thick lag screws and attach to the wall studs for the entire length of the ledger. Drill the lag screws into wall studs on a single-story or the band joist on a two-story. Use expanding anchor bolts to attach to brick.
Attach joist hangers to the ledger to secure the rafters. Install them at 16 inches or 24 inches on center. Erect and plumb the two support posts at the other end of the patio. Join them with a ledger that will receive the other end of the patio roof beams. Nail in joist hangers/saddles to line up with the hangers already installed in the ledger attached to the house.
Mark the patio roof rafters with a sliding bevel to give the rafters the required drop angle. Cut and drop them into the joist hangers. Check the end posts for plumb one more time. Nail them into the rafter hangers and saddles. Nail in the rafters on each end first, then the others. Chalk and cut the rafters to the same length, after they are all installed. Nail up the 2-by-8 fascia board, attaching it at the rafter ends.
Install sheathing to cover the rafters. Stagger the sheathing seams every four feet to avoid continuous seams. Cover the sheathing with roofing felt. Install the drip edge and shingles.