Check to be sure that the area around the perimeter of your existing patio is level. Add fill dirt if needed to even out the site.
Contact your local utility and cable companies to be sure that there are no hidden lines in the installation area. Check your local code office for any necessary building permits.
Make an outline for the pergola with string and stakes. Corner posts should be 8 feet apart on each side. Verify the measurement by measuring diagonally from both sides. The measurements should be the same.
Dig four corner holes for the footings, using a post-hole digger. Dig the holes 2-feet deep and 12-inches wide.
Pour 3 inches of crushed gravel into the post holes. This will aid in drainage.
Ask an assistant to help you set the poles into the holes. Check to be sure the posts are even, using a level. Keep each corner post level by placing two diagonal bracing boards on the post at a 90-degree angle to each other. Attach the bracing boards, using a hammer and nails.
Pour one bag of concrete into the wheelbarrow and begin adding water and mixing. Each hole will use approximately four bags of concrete and 6 gallons of water. Mix thoroughly after adding each bag of concrete and while adding water slowly. The cement mixture should be the same consistency as peanut butter.
Pour concrete into a post hole. Do not fill the hole all the way full, but leave a 1-inch margin at the top to accommodate expansion and retraction. Using a shovel, turn the concrete in the hole as you fill to ensure there are no air pockets.
Install the other three posts in the same manner. Allow the concrete to set for 48 hours. Remove the brace pieces.
Position a step ladder just outside of one corner post and another step ladder outside of the opposite post. Ask an assistant to help you lift one of the 2-by-4-by-10-foot boards up and place it on the interior of one side of the pergola, flush with the top of the posts and the decorative curve facing downward. Adjust the board so that there is an even overhang on both ends. Attach the board to the posts, using exterior wood screws. Attach another 2-by-4-by-10-foot board to the other side in the same fashion.
Measure the distance from outside post to outside post. Cut two side beams out of 2-by-8-foot wood to fit on either side of the frame, using a circular saw. Attach the boards to the frame, flush with the post tops, using exterior wood screws and a drill.
Space the 12 2-by-4-foot boards on their sides evenly across the top of the frame vertically between the two decorative side pieces. Adjust the boards to have an equal overhang on each side. Attach the boards to the side pieces using exterior wood screws.
Paint or stain the pergola with a high-quality exterior finish to match your existing outdoor decor.