How to Build an Arch Entryway

Cut away the drywall around the entryway using a utility knife until the framing is exposed. If there are corner beads at the corners, use a hacksaw to cut them out. You should be left with a rectangular entryway.

Measure the distance between both sides of the entryway.

Tie a pin to one end of the string and a pencil to the other end. Lay the large piece of cardboard on the floor. Push the pin through the center of the cardboard. Pull the string away from the pin until it is fully stretched and begin drawing a circle.

Remove the pin and cut out the circle. Divide the circle into two equal semi-circles.

Position one of the semi-circles at the bottom of the top frame and tape it into place. Move back and examine the arch formed to ensure that you would have enough room to walk underneath.

Trace the outline of the semi-circle onto two pieces of 1/2-inch plywood and cut them out to get two plywood arches.

Position the plywood arches on either side of the frame and nail them into place using 2-inch nails, ensuring that the arches coincide.

Cut drywall to the size of the plywood arches and cover the arch with one piece of drywall on each side. Cut off any excess drywall using a utility knife.

Saw the wooden blocks to the shape of the arch and nail them in between the plywood pieces using drywall screws.

Position the hardboard directly underneath the wooden blocks and nail it into the blocks using 2-inch nails. Bend the hardboard to curve along the arch as you are nailing it into place.

Measure the distance between the plywood pieces and cut a strip of drywall to these measurements exactly.

Immerse the strip of drywall in water completely and let it soak until it becomes flexible.

Position the drywall strip beneath the curve of the arch and screw it unto the hardboard using drywall screws.

Apply corner beads to the edges and staple them into the drywall. These beads are flexible so you can push them to the shape of the arch edges.

Apply joint compound to the archway, covering the beads in a double layer. Let the arch dry.

Sand the arch with sandpaper and paint to your liking.