How to Drywall an Arch

Add an arch to a doorway for a stylish feature.

Arches in drywall are a common design element in Mediterranean architecture. Arches can also be added into standard passageways in a traditional or modern home without any major complications. Once the arches are cut into the passageway, the final step is adding drywall over the wall cavity to create a finished appearance. This is a rather simple process that anyone with minimal building skills can complete in a short amount of time.

Things You'll Need

• Flexible tape measure
• 1/4-inch thick drywall
• Pencil
• Straight edge
• Drywall saw
• 5-inch screws
• Drill
• Phillips head drill bit
• Drywall plaster
• Drywall tape
• Putty knife
• Drywall sanding block

Instructions

1. Measure the wall cavity between the two walls joining the arch. This distance can be a couple inches to a few feet, so measure accurately to the nearest 1/8 inch.

2. Measure one of the arch sides with the flexible tape measure. Curve the tape measure along the arch to find the measurement of the total arch area you will cover with drywall.

3. Draw an outline of the measurements onto the 1/4-inch sheet of drywall with a pencil. Mark your measurements and use a straightedge to guide you for straight lines. For an easier marking, use a corner as a starting point. This will eliminate the need to draw on a full rectangle or square, allowing you two use two outer edges as sides of the arch cover.

4. Cut along the lines with a drywall saw. Cut carefully to avoid damaging the drywall.

5. Curve the drywall section into the arch cavity on the wall. Press drywall in carefully at the bottom, allowing some of the drywall to stick out until you can secure it in place.

6. Drive two 5-inch screws through the drywall to join it with the underlying wall studs. The wall studs may be set back a little, which is why 5-inch screws are used to bridge the gap. Press the drywall into the cavity until it is flush with the joining drywall and screw it in place.

7. Cover the new drywall section with a thin layer of drywall plaster. Tape along the joining edges and apply a thicker layer of plaster over top the tape. Allow drywall to dry completely before continuing.

8. Sand away excess plaster using a drywall sanding block. This will smooth out the drywall over the arch, creating a seamless finish. Apply a second coat of plaster if any tape is exposed and re-sand when dry. Paint the arch as desired.

References

• "Extraordinary Interiors: Decorating with Architectural Salvage & Antiques"; Brian Coleman, et al.; May 6, 2005