Pergolas are outdoor structures that are composed of four or more beams and feature evenly spaced apart vertically placed wooden planks. Pergolas do not provide much shelter from rain or even sunshine, but they do define an open space without adding constricting walls. Pergolas can be placed over pathways or sit on the lawn to provide a defined seating area. When climbing vines are added to pergolas they can offer shade as well as protection from rain. Pergolas are easy to build since the design is very simple and straightforward.

Pergolas can be built in 3 easy steps
- You must first select where you want to build the pergola and then mark the placement of the posts. Only four posts are required. Use a post-hole digger or other implement to dig holes to a 24 inch depth. The width should be 9 inches. A few inches of gravel should be added to the bottom for drainage. Place posts and make sure they are even. Attach a temporary brace to hold in place. Mix and pour cement. Let this cure for 24 hours.
Cut the joist beams from boards that are 2×10 in size. Wooden boards can be cut to provide a decorative design. Clamp into place temporarily on the inside of the posts and then drill holes through posts and beams. Use 3-inch lag bolts to attach the beams.- Cut 2×6 boards into stringers so that they overhang the joist beams. Creating designs on the wood ends can be accomplished by drawing a curved or straight line and then cutting. The stringers should be evenly placed at a perpendicular angle to the beams and then attached with galvanized 3-inch deck screws.

Pergolas can add a focal point to any yard and provide a decorative touch that enhances the look of the space without creating obstructions.
Sources:
http://www.popularmechanics.com/home/how-to-plans/pergola/3352816






