How to Build an Arch-Top Door

Measure the height and width of the inside of the door frame, using a tape measure. Note the measurements on a piece of paper. Divide the width of the door by 2 to find the height of the arch. Note the arch height on the sheet of paper also.

Cut a sheet of 1 1/2-inch-thick plywood to a length equal to the width of the door and a width equal to the arch height, using a circular saw. Cut a piece of string to the height of the arch using a pair of scissors. Tape a pencil to one end of the string. Pin the other end of the string to the middle of one door width-long side of the plywood with a thumbtack.

Draw an arc on the plywood sheet using the pencil. Halve the length of the string. Draw a second arc on the sheet. Cut along both arc lines using a jigsaw, to form the top of the arch. Fit a 1/2-inch pilot bearing to the router. Cut a 1/2-inch-deep rabbet along the middle of the smaller curve in the arch.

Cut two sheets of 1 1/2-inch-thick plywood to a length equal to the height of the door minus the height of the arch, and a width equal to half the height of the arch. Cut a 1/2-inch-deep rabbet down the middle of one of the door height-long edges on both sheets.

Fit a 1/2-inch drill bit to the drill. Drill two 1-inch-deep holes in one end of both door-height plywood sheets, 1 inch from either edge of the sheet. Drill two 1-inch-deep holes in both ends of the arch, 1 inch from either edge. Cut the dowel into eight 2-inch-long pieces.

Apply wood glue around the circumference of four of the dowel pieces. Tap the pieces into the holes in the arch using a hammer. Fit the arch onto the height-long sheets via the dowels. Tap the arch down onto the other sheets using the hammer until the arch is flush with the height-length pieces.

Cut a sheet of 1 1/2-inch-thick plywood to a length equal to the half the width of the door and a width equal to half the height of the arch. Cut a 1/2-inch-deep rabbet along one of the half-door-width edges of the sheet using the router.

Drill two 1-inch-deep holes in the half-arch-height ends of the plywood sheet, 1 inch from the sides. Glue the circumferences of the remaining four dowel pieces. Tap the pieces into the holes in the plywood sheet using a hammer. Stand the sheet inside the door frame so the bottom of the sheet is flush with the bottom of the two door height-long pieces.

Mark on the door height pieces the points where the dowel pieces touch them, using a pencil. Drill 1-inch-deep holes at these marked points. Cut a sheet of 1/2-inch-thick plywood to a length equal to the height of the door minus 1 1/2 times the height of the arch plus 1 inch, and as wide as half the width of the door. Slide the sheet into the door frame.

Line up the dowels on one side of the remaining 1 1/2-inch-thick plywood sheet with the holes in one side of the door frame. Tap the other end of the plywood sheet until it is flush with the door frame. Line up the dowels on the other side of the sheet with the remaining holes in the frame. Tap the frame until the sheet is flush with the frame, to complete the door.