You can add architectural interest to your home by softening a few of its right angles with curved archways. Although it is a normally rigid material, drywall you can wet drywall and manipulate it from its usual flat state to bend along an archway. The drywall is then secured to the framing of the home and allowed to return to its original hardness with the contour of the arch locked in place.
Stand underneath the arch and measure the distance from the outside edge of the framing on one side to the opposite wall of the other side to determine the width of the piece you need cut down. Save this measurement.
Measure the length of the piece as well. Press the tape measure against the start of the arch on either the left or right side of the archway, and push the tape up into the arch of the doorway all the way to the other side and save that measurement.
Put on your safety gear. Mark your piece of drywall according to your measurement. Place the blade on the pencil mark, line the T-square up with the edge of the drywall and pencil mark, and press your blade into the drywall sheet the length of the square. If necessary, flip the square around to the other side of the board to guide your blade for longer cuts. Snap the drywall in two by applying pressure along the cut area.
Spray the back of your piece of drywall with the water bottle until the entire surface is damp. Allow it to sit for at least five minutes or until the piece becomes pliable.
Press the piece of drywall into place and gently force it to follow the curve of the arch. Work with a companion for best results to hold the board in place.
Secure the drywall to the wooden framing with drywall screws. Start at the top of the archway and work your way down each side independently, pressing the damp drywall against the arch of the framing and screwing it down every 3 to 4 inches -- wherever there is a block supporting the wooden framework of the arch.