How to build freestanding decorative arched doorway — 36" clear opening

Cut list

Step by step

1. Shape the arch

   Mark the circular arch on the loose head facing and cut only its curved opening.

   • Clamp the facing flat on supports with clearance below the entire arc.
   • Mark the center on scrap 7 1/2" below the bottom edge and 24" from either side.
   • Mark the arc ends 6" from each bottom corner.
   • Draw the upper arc with a 19 1/2" string compass.
   • Saw only the arc with a jigsaw from one marked end to the other.

2. Shape the side braces

   Shape both loose plywood braces into matching triangles before assembly.

   • Mark the peak 15" from either end of each top edge.
   • Draw a line from each bottom corner to the peak.
   • Clamp each blank flat with the waste supported separately.
   • Guide the jigsaw along a straightedge clamped beside each diagonal.

3. Smooth the exposed edges

   Sand all loose parts before the frame is assembled.

   • Support each loose part on a clean work surface.
   • Sand exposed edges with 180-grit abrasive.
   • Ease the arch edge and brace peaks lightly.
   • Remove sanding dust with a dry cloth.

4. Assemble the upper frame

   Join the top rail between the uprights with all top edges flush.

   • Support the uprights and rail flat on padded sawhorses.
   • Clamp the rail between the uprights with an outside width of 48".
   • Drill 2 pilot holes through each upright into its rail end.
   • Drive the 4 screws with their heads flush.

5. Attach the base runners

   Fasten each centered base runner under its upright while the frame remains supported.

   • Support the frame on its side with a helper.
   • Center each 36" base beneath its upright.
   • Clamp each base square to the upright.
   • Drill 2 pilot holes upward through each base.
   • Drive the 3" screws flush with the base underside.

6. Attach the side braces

   Secure each triangular brace to its upright and base runner.

   • Clamp each brace against the outer upright face and base top.
   • Center each 30" brace along its base runner.
   • Drill the 3 face pilots and 4 upward base pilots for each brace.
   • Drive the 2" screws through each brace into its upright.
   • Drive the 2 1/2" screws upward through each base into the brace edge.

7. Attach the doorway facing

   Fasten the straight side facings and curved head facing to the supported frame.

   • Support the frame face-up with both bases clear of the floor.
   • Clamp the side facings flush with the outer upright edges.
   • Clamp the arch facing above the sides with its top flush.
   • Drill pilot holes at the marked framing centers.
   • Drive the 1 1/2" facing screws flush.

8. Position the completed doorway

   Stand the completed decorative doorway on a level indoor floor with a helper.

   • Lift the completed doorway upright with a helper.
   • Place both runners fully on a level indoor floor.
   • Check both uprights with a level.
   • Inspect all joints for movement.
   • Keep the projecting runners outside normal walking routes.