You can replace just door but new prehung might be cheaper

Q. My wood front door needs to be replaced, but I want to save some money and not remove the entire frame and jamb. What is the best way to install a new wood front door in the existing door frame?

A. The door itself usually takes much more abuse over the years than the door frame and jamb. You can save some money by installing just the door itself, but it often is easier to remove everything and install a new prehung door. Check the pricing at your local home center store before making your decision on just a new door or a complete prehung door.

To install a new wood door in the existing door frame, accurately measure the height, width and thickness of your existing door. Purchase a new door which is as close as possible in size to the existing door. Most likely, the old door is a standard size. None of the dimensions of the new door should be smaller than the existing door. An edge of a door can always be trimmed down, but it is extremely difficult to add to the size.

Mark the outdoor surface of the new door with a strip or two of blue masking tape on the hinge side. It might sound silly, but when working on a door and flipping it over several times on a work table, it is easy to get mixed up on which side is which. This is particularly important so the latch edge of the door is properly beveled.

You will need the assistance of a helper to handle the door. If the door threshold is adjustable, adjust it to its lowest setting on the floor. Place the new door in the existing door frame and have the helper hold it against the door jamb. Using tapered wooden shims, shim it up from the threshold so it is centered in the door frame.

If your house is very old, the door frame make no longer be square. This will be apparent when the new door is shimmed and centered in the door frame. Plane a slight bit off the top of the door (called cheating) so it fits more evenly along the top. Although this step is not necessary, it looks better from indoors when the gap a the top of the frame is more uniform.

With the door securely held in the frame, mark the vertical locations of the hinges using a scribe. The hinge locations determine the finished position of the door. If you have to remove material from the width for a good fit, it should be removed from the hinge side. It is better to leave more material on the latch side in case you install a deep lockset.

When trimming the door to size, always score the cutline with a sharp utility knife. This minimizes the chances of tearing out some wood when the saw blade cuts through the wood surface. Using a circular saw, saw within about 1/16 inch of the scribed line. Remove the remainder of the wood to the scribe line with a plane.

Next bevel the side edges of the door so it clears the frame when it swings open. The final step is to screw the hinges to the door and check that it swings freely.

Starcott Media Services