How to Cut an Arched Doorway

By Paul Miceli

An arched doorway can add style to a home and creates an impressive entryway that is both grand and inviting. Although the prospect of creating an arched doorway may seem like a large job, it’s actually quite simple for anyone with basic woodworking skills. The task utilizes a basic method that can be used for all arched doorways, irrespective of size, and it requires no specialized tools or knowledge.

List of Items Needed

  • Plywood
  • 2-inch-by-4-inch lumber
  • String
  • Framing square
  • Pencil
  • Tape measure
  • Nail
  • Hammer
  • Circular saw or handheld cutting tool
  • Screws
  • Screwdriver
  1. Take a piece of plywood measuring 8 feet by 4 feet by ½ inch in thickness; this will be the basis for your arched doorway. Measure the width of the doorway where the arch will be located. Remember that most arches are 3 feet wide so gauge measurements accordingly.

  2. Make one line on the plywood 12 inches in from one of the long sides. Add another line 1 inch from the top on the shorter side and a third line 9 inches down from the top on the shorter side. This will create a rectangle on the plywood measuring 36 inches wide by 9 inches deep.

  3. Measure and mark a line, thus dividing the plywood into two 18-inch-wide rectangles and extend the line across the entire length of the plywood. Draw a diagonal line from the bottom outside corner of the rectangle to the point where the center line crosses the top of your rectangle. Note the length of this line, then make a mark halfway along its length. Draw a straight line from the mark until it intersects the center line below the rectangle. Put a nail into the plywood at this point.

  4. Tie the string around the pencil and place the pencil point on the bottom left-hand corner of the rectangle. Pull the string taut and loop the end over the nail. Draw a line clockwise around the rectangle to create the arch shape; it should touch the line near the top of the rectangle at the center, and finish at the other bottom edge of the rectangle. Cut out the shape with a circular saw or a handheld cutting tool and use it as a template to create another arch of the same size.

  5. Measure the thickness of the wall where the arch will go (4 inches, for example). Position your two arch pieces with one on top of the other; together, they should be 1 inch thick. Cut blocks of the 2-inch-by-4-inch timber to 3-inch lengths. Nail the blocks around the straight edges of the arch. Insert screws through the blocks to secure the arch into position. Add blocks on the curved underside of the arch. To finish, cover the arch with plaster, smooth, sand and paint to match the walls.

© Demand Media 2011