Shorten a Door

There are several occasions when it might become necessary for you to shorten an existing door. The installation of new carpeting or an area rug are perhaps the most common reasons. Adding air space under a bathroom door for more efficient operation of bathroom fans is another reason (you need about a 1-in. gap to allow replacement air to enter). You may also need to shorten an exterior entry door when installing weatherstripping on the door's bottom. Here are basic instructions for shortening a hollow-core or solid-wood door.

Materials List:

• Tape measure
• Wood glue
• Straightedge and pencil
• Sanding block
• Retractable utility knife w/blades
• Medium and fine-grit sandpaper
• Clamps
• Wood finish that matches door
• Circular saw

1. Mark the Door: If you can install and close the door, do so. Lay a 1/2-in. thick board on the floor against the door and use it to guide your pencil while you mark a line on the door. If you can't install the door, measure the distance from the head jamb to the floor (or carpeting) at the left and right side of the opening. Subtract 5/8 inch from each measurement (to include a 1/8-in. gap above the door plus a 1/2-in. gap below the door). Transfer dimensions to the door and connect these points with a straightedge.

• Tip: If you don't have a 1/2-in. board, use any size and either add or subtract from the line drawn when penciling the final cut line.

2. Score the Veneer: To prevent the up-cutting circular saw blade from chipping the veneer, clamp a metal ruler or other straightedge to the door on your cut line and cut through the veneer using several passes with a utility knife. Use the same procedure to prevent chipping when cutting across the grain of a solid-wood door's vertical stiles.

3. Make Guided Cut: Clamp a straightedge to the door to guide a circular saw along your cut line. Make sure the saw blade remains about 1/16 inch away from the cut line on the waste side. Skip to Step 7 for solid wood doors.

• Tip: Place two pieces of scrap lumber lengthwise under the door, so they support the door and the cutoff. Then you don't have to support the cutoff with a free hand, or worry about the damage to the unscored underside veneer that may occur if it is allowed to fall free.

4. Clean off Core: If your cut exposes the hollow portion of the door, you must reinstall the solid-wood rail from the cutoff. Start by making room for it by pushing in the ribbed cardboard or wood-strip core and scraping off any glue from the inside face of the veneer.

5. Salvage the Rail: Peel the veneer off the cutoff. Scrape and/or sand the glue residue off the rail. If the two stile sections on the ends of the rail don't just fall off, break them off.

6. Reinstall Rail: Apply wood glue to both faces of the rail and insert it into the door bottom until it is flush with the bottom edge. Do not push too far, as it may be difficult to pull out. Wipe off any excess glue and apply two or three clamps for at least an hour.

7. Sand and Seal: Use a sanding block with medium- and then fine-grit sandpaper to round over and smooth the cut edges. Seal the bottom edge of the door with a finish to match the door (varnish or primer-and-paint). If you don't, particularly with a solid wood door, the door will absorb moisture and may warp.

Writen by Roy Barnhart, home improvement expert, Fairfield, CT.

Courtesy of HardwareAndTools.com A commercial sales member of True Value Company