Getting right fit, hang for interior door can take work

Q: My son got angry and kicked a hole in a door. Now I get to replace it. It is a flat, hollow interior door with no panels. I’d like to just take the door off the hinges and install a new door, rather than install a more expensive pre-hung door. How difficult is this?

A: Hollow-core interior doors are inexpensive to replace. However, getting them to hang just right is a different matter altogether.

To start, measure the door and buy a replacement at a home center. The door you purchase will probably be slightly larger than the one you are replacing. Don’t worry about that; you will just have to trim it.

Unless you have some specialty tools, buy a door that comes pre-bored for the handle and latch.

Remove the doorknob by removing the two screws that keep it secured to the door. The screws may be visible, but most likely you will have to remove a cover plate on one side of the doorknob. Lift it off with a standard screwdriver and remove the screws.

Knock the hinge pins up and out and lift the door off. Remove the hinges from the door and set them aside.

At this point, you’ll use the old door as a template to mark and cut the new door. On a hollow-core door, only the edges have solid wood. This gives the hinge screws and doorknob something to bite into. (Hey, there’s an idea for your son!) It also gives the hollow door some rigidity.

Lay the new door down and then lay the old door on top of it. Make sure the holes for the doorknob are aligned and the front edge is even. Use a pencil and trace around the old door to make lines on the new one.

You should need to cut only a sliver from the back edge of the door. If you cut too much, the hinge screws won’t have anything to bite into. If your door isn’t a standard size, you may have to order a custom door.

The best way to trim the back edge of a door is with a table saw, but a circular saw with a guide works equally well.

Use a circular saw to trim the height of the door, but make sure that you don’t change the position of the doorknob hole. For example, if the doorknob hole is 35 inches from the bottom of the old door, make sure it is in the new door, too.

When the door is cut to size, mortise the hinges. In this case, mortising refers to cutting the exact depth of the hinge into the edge of the door so that when the hinge is screwed in, it sits flush with the door.

Stand the old door and the new door on edge so that the doorknob holes are aligned and facing down. Mark the locations of the hinges on the back edge of the new door.

The quickest, most accurate way to cut a mortise is with a router and a hinge template. However, if you don’t plan to do a lot of woodworking, forgo the expense of these tools and go with a faithful standby: the hammer and chisel.

Take the hinge and trace its outline in the locations you marked. Be sure that the hinges are in the same locations as the old door. Tap the chisel along the outline to cut the edge of the mortise. Then take shallow passes to remove the wood inside of the outline. Occasionally test the depth of the mortise by inserting the hinge. If the hinge is not flush, remove more wood until it is. Repeat for the other hinges.

When the mortises are all cut, screw the hinges into the mortises. Stand the door up and rehang it by aligning the hinges and installing the hinge pins.

Test the swing of the door. If it sticks along the top or side, use a block plane to smooth out the contact point. It is likely you will have to tinker with the door to get it just right.

Reinstall the handle and latch and make sure they contact the strike plate. If it doesn’t latch, leave the door alone and move the strike plate. It’s much easier than recutting the hinges.

When the door operates to your liking, paint it and consider taking your son to the soccer field.

Mike Klimek is a licensed contractor and owner of Las Vegas Handyman. Send questions to handymanoflasvegas@msn.com or 4710 W. Dewey Drive, No. 100, Las Vegas, NV 89118. Visit handymanoflasvegas.com.