How to Build an Archway With Wood

Measure and mark 14 segments of 19 3/4 inches along the two 2-by-6 pieces.

Measure and mark four segments of 9 7/8 inches along the two 2-by-6 pieces.

Set the miter saw to 22.5-degrees.

Cut along the marks on the 2 by 6 boards with miter saw. Angle the cuts so that each piece has one long side one shorter side.

Measure and cut a 20-inch long piece of string.

Hold the string horizontally along the plywood edge. Press one end of the string down against the plywood. Hold the pencil to the other end of the string.

Hold the string tight, move the string and pencil in an arch over the plywood while holding the other end tight. You should have drawn an arch with a 20-inch radius. Mark the location where you held the stationary end of the string.

Cut a piece of string to 23 1/2-inches. Hold one end on the mark along the edge of the plywood in the middle of the arch. Hold the other end with the pencil, stretched tight. Move the string and pencil in an arch exactly as in the previous step. You should now have a 23 1/2-inch radius arch enclosing a 20-inch radius arch. Cut the arch out with the jigsaw to make a template.

Make an arch by laying out the miter cut 2-by-6 pieces end to end. Start with a short piece, then three long pieces and finish with another short piece. Cover the arch with a layer of wood glue.

Lay out four long miter cut pieces over the first arch. You should have two over lapping arches. None of the edges of the bottom arch should be in the same position as the edges on the top arch.

Attach the top arch pieces to the bottom arch pieces by drilling six screws through each segment.

Lay the round template over the unfinished arch of 2 by 6 pieces. Trace the outer and inner radius of the template onto the arch. Remove the template.

Trim the arch with the jigsaw following the traced lines from the template. You should now have a solid, 4-inch thick, 40-inch diameter curved arch.

Repeat Steps 9 through 13 with the remaining miter cut pieces. Allow for the glue to dry on both arches, then sand the edges to a smooth finish.

Lay the arches upside down, parallel to each other so that they are 40-inches apart with their ends sticking up.

Lay two of the 1 by 4-inch boards over the ends of the arches so that the two ends of one board are laying over one end of each arch. Screw the boards into the ends of the arches. Both arches should be connected as one unit. Turn the arches over so that they rest on the 1 by 4-inch boards.

Place four of the 40-inch wood strips on top of the arches, screw them to the arches to add extra support.

Screw the remaining two 1-by-4-inch boards to the ends of of the 4-by-4-inch posts. The posts should be at either end of the long boards. These will form the support units.

Lay six wood strips along each support unit, parallel to the 1-by-4-inch boards that connect them at the top. Screw the strips into the posts to provide extra support.

Place the concrete blocks in position where you want to install the archway. The blocks should form a square with four 40-inch long sides.

Place the posts into the brackets on the blocks. Attach the posts to the brackets with screws.

Place the archway unit on top of the support units. The 1 by 4-inch boards that connect the arches should be placed directly on top of the 1 by 4-inch boards that connect the posts.

Drill 6 1-inch screws through the each of the boards so that the arch unit is connected to the support units.