Ledger Board

• Install a ledger board to the house structure. Use a pressure-treated 2-inch by 8-inch board mounted flat against the wall of the house. It is best to secure the board to the wall, and under the edge of the roof (one-story home) through the sheathing, and into the framing structure. Follow the local code requirements for fastening the board to the wall studs or floor joists.
  
  Use ½ -inch diameter lag screws to fasten the ledger board to the house. Apply a generous amount of construction adhesive to the back of the board. Extend the flashing over the ledger and over the siding below. For a masonry wall, use expanding masonry bolts to fasten the board to the wall surface.
  
  

Posts & Beam

• The final height of the posts and support beam will be lower than the ledger board, which will allow for water to drain. Extend the patio cover about 17-inches beyond the front edge of the patio. Dig holes for the post every eight feet in front of the patio. Pack the soil and place gravel in the bed. Install treated 4-inch by 4-inch posts. Use 2-inch by 4-inch braces to hold the posts in place until you pour the cement and it cures. Make sure the posts are straight and level before adding the quick-setting cement.
  
  Build the cross beam by fastening a piece of 3/4-inch plywood between two 2-inch by 12-inch planks. You can also purchase a prefabricated pressure-treated beam. Attach the beams to the posts with metal brackets.
  
  

Rafters

• The patio cover rafters should be long enough to provide the 17-inch overhang. Use 2-inch by 8-inch and place them 24-inches on center. Attach joist hangers to the ledger board and install the rafters. Secure the two end roof rafters to the ledger board first. Make sure that the rafters are straight. Fasten metal joist saddles on top of the cross beam secure the rafters in the saddles.
  
  

Sheathing and Covering

• Start installing the 5/8-inch plywood from the front end of the patio cover and work toward the Install the plywood perpendicular to the rafters and stagger the seams, which help strengthen the structure. Install plywood clips, which will keep the spacing between the sheets and allow for the expansion and contraction of the plywood.
  
  Apply roofing felt or a peel and stick weather barrier over the roof decking. Cover the roof with shingles or another type of roofing material.