How to Make an Arch for Hallways

Cut the drywall surrounding the hallway entry with a utility knife until the framing is exposed around the sides and the top. If there are corner beads present in the edges of the entry, remove them using a hacksaw.

Push a pin through the center of a cardboard piece and tie a string to it. Tie a pencil to the other end of the string. Pull the string away from the center of the cardboard until it is fully stretched. Start drawing a circle on the cardboard. Keep the string stretched as you are drawing to end up with a perfect circle.

Cut the circle out from the cardboard with scissors and divide the circle into two equal parts to get two cardboard arches.

Tape one of the arches to the bottom of the top frame to ensure that you have enough space underneath to walk in and out of the hallway.

Trace the outlines of the cardboard arch onto two pieces of 1/2-inch plywood and cut them out with a saw to get two plywood arches.

Position the plywood arches on either side of the top frame the same way you did with the cardboard arches, making sure that they coincide. Nail them into the top frame using 2-inch nails.

Cut two pieces of drywall that resemble the size and shape of the arches. Position them over the plywood pieces and screw them into place using drywall screws.

Trim the small wooden blocks until they can fit smoothly between the plywood pieces. Shape them with a utility knife so that they run along the curve of the arch. Screw drywall screws through the plywood and into the wooden blocks to secure them in place.

Cut a strip of drywall that is as thick as the arch. Soak it in water for an hour so that it becomes flexible enough to bend into the shape of the arch.

Position the drywall strip directly underneath the wooden blocks and nail it into the blocks using 2-inch nails, bending it into the shape of the arch as you go along. Space the nails at least 4 inches apart.

Apply flexible corner beads to the edges of the arch to help retain its shape. Bend the beads tight against the drywall and secure them with a stapler.

Mix the joint compound and apply it to the corner beads to cover them. Apply a second layer if required. Let the arch dry.

Sand the arch and paint it.