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How to Build an Angled Pergola

By Jonah Morrissey
A cat enjoys a bird's eye view atop a pergola.
katze auf der pergola image by Falkenauge from Fotolia.com

Pergolas add a decorative element to any outdoor space. In addition to decoration, pergolas can provide several functions, providing shade, defining a space, and providing a structure for vines and vertical growing plants. Grapes and ivy, for example, grow well on pergolas. The foliage also provides extra shade. A standard pergola has no angles, but some outdoor spaces might work better with an angled pergola. A salt box-style house is one example of a place an angled pergola would look best.

Cut the top ends off two of the 4-by-4-by-96-inch posts at a 14-degree angle, using a miter saw. These are the front corner posts of the angled pergola. Cut the top ends off two of the 4-by-4-by-72-inch posts at a 14-degree angle, using a miter saw. These are the back corner posts. Measure up 36 inches from the bottom of the front and back corner posts. Mark this measurement with a pencil.

Measure in at 12 inches and 30 inches from both ends of the remaining four 4-by-4-by-96-inch posts, using the measuring tape. Mark these measurements with a pencil. Measure in at 12 inches and 36 inches from the ends of the remaining 4-by-4-by-72-inch posts. Mark these measurements with a pencil. Set up the dado set on the table saw. Set up the table saw to make a 1 1/2-inch-deep-by-3 1/2-inch-wide dado cut. Run a test piece of 4-by-4 post through the saw to make sure the saw is set up to make a correct cut. Cut a dado on the center of the pencil marks on each of the posts. These posts will form the interlocking grid of the roof.

Position the four 4-by-4-by-72-inch posts parallel to each other with the dado cut facing up. Lay the four 4-by-4-by-96-inch posts perpendicular to the 4-by-4-by-72-inch posts with the dado cut facing down. Lock the posts together, placing the upward-facing dado cuts into the downward-facing dado cuts. The boards will form a grid. The grid will form the roof of the angled pergola.

Screw one 2 1/2-inch coated deck screw at each intersection of the 4-by-4-by-72-inch and 4-by-4-by-96-inch posts, using a screw gun. Flip the pergola roof over. Place the two front corner posts on the center of the first intersection point of each front corner of the roof. Align an L-bracket with the post. Fasten the bracket to the post and the intersection point on the roof, using a screw gun and the screws provided with the brackets. Do the same for the back corner posts.

Fasten the two 2-by-4-by-48-inch boards to outside of the front and back posts at the pencil mark you made on them at 36 inches. Use a screw gun and two 3-inch deck screws per end. These will support the pergola on the sides. Flip the pergola upright and move to the desired spot in your yard.


Things You Will Need

  • 6 4-by-4-by-96-inch Douglas fir posts
  • 6 4-by-4-by-72-inch Douglas fir posts
  • Miter saw
  • Tape measure
  • Pencil
  • Table saw with dado set
  • Screw gun
  • 16 2½-inch coated deck screws
  • 2 2-by-4-by-48-inch Douglas fir boards
  • 4 L-brackets with screws
  • 8 3-inch coated deck screws


  • Plant vines or other vertical-growing plants such as grapes on each side of the pergola. Over time the pergola will be shaded with the foliage.


  • Wear eye protection when working with wood.
  • Follow tool safety precautions carefully.

About the Author


Jonah Morrissey has been writing for print and online publications since 2000. He began his career as a staff reporter/photographer for a weekly newspaper in upstate New York. Morrissey specializes in topics related to home-and-garden projects, green living and small business. He graduated from Saint Michael's College, earning a B.A. in political science with a minor in journalism and mass communications.