How to build an angled pergola

Updated February 21, 2017

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 mitre 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 mitre 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 centre 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 centre 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.


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.

Things You'll Need

  • 6 4-by-4-by-96-inch Douglas fir posts
  • 6 4-by-4-by-72-inch Douglas fir posts
  • Mitre 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
  • Screw gun
  • 4 L-brackets with screws
  • 8 3-inch coated deck screws
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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.