Sometimes your door must be cut down to open properly. New carpeting or flooring, putting in a threshold or buying a new door will sometimes cause rubbing or binding. You’re going to have to cut down the door.
To cut off a door without chipping the wood, draw your door clearance line with a pencil. Then score another line with a utility knife a fraction of an inch above the clearance line to create an edge where the wood will not splinter when cut. The knife cuts the wood veneer so splintering won’t occur when the circular saw cuts. You can clamp on a straight edge as a guide for the circular saw cut or do it free hand. The blade can’t be dull, but it doesn’t have to be a great blade.
To protect the face of the door from scratches from the circular saw base, you could put wide strips masking tape along the face to protect the door.
Cut the door with the good-side down because the saw blade cuts up. Chipping occurs when the blade cuts down. The blade teeth should be just outside of the scored line. Cut slowly.
Finally, lightly sand all the edges at a 45 degree so the sharp edges don’t catch the flooring, and the edges will hold paint better.
Hollow-core doors have a 3-inch block of wood in the bottom of the door. After you cut, be sure the door bottom is still solid. If not, replace the solid section that was cut off. You can recover the solid section from the piece you cut off from the door, then strip the veneer off, and glue the block of wood into the hollow opening so it’s flush with the bottom.
Remember: Wear on safety glasses.
Important: Pull open the fence, and do not allow the blade to touch the wood before starting the saw because it will kick.