A door that's installed well closes tightly and quietly and doesn't swing open on its own. That means it's been trimmed to leave a very small gap next to the jamb, or, as This Old House general contractor Tom Silva explains, "about the width of a nickel." What he means is: Make it just under inch. So measuring and trimming the door before installation must be done carefully and precisely.

In the same vein, the various mortises on the door—the recesses in which the hinges sit or the lockset slides—must be carefully cut out. Too deep and the door won't close properly and might spring open. Too shallow and you'll get creaks and scrapes every time you move the thing. The key to a good mortise is a sharp chisel and a steady but light hand. This is not the time to bang and dig with all your strength.

The good thing about doors these days is that you don't have to spring for the expense of solid wood to get its look and feel. Many doors are made from solid medium-density fiberboard (MDF) or are so-called "solid-core" doors, which means they have a veneer of wood or MDF over a core of particleboard or wood pieces. They're not only better at soundproofing than hollow-core doors but more resistant to warping than solid wood. In fact, MDF is one of the most stable materials you can choose. However, if you intend to use a stain or clear finish on your door instead of painting it, you'll want to get one with solid wood or wood veneer.
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    Tools List

    • folding ruler
      Tape measure and folding ruler
    • circular saw
      Circular saw
    • bench plane
      Bench plane
    • combination square
      Combination square
    • wooden mallet
    • drill
      Drill/driver with auger bits
    • centering punch
      Centering punch
    • ratcheting screwdriver
    • hand clamps

    Shopping List

    1. DOOR

    Measure the width of your opening, jamb to jamb, in three places (top, middle,bottom) and the height, threshold to jamb, in three places. Note the largest of each and use these as a guide to buy the door.

    2. KNOB SET

    A set for a cylinder lock should include two knobs, a spindle, and two round escutcheon plates. For a mortise lock with a bolt, two escutcheons or a long backplate with a keyhole may be required.

    3. LOCKSET

    Choose between a cylinder lock (a tube-shaped ;acthset with a lock on the knob) or a mortise lock (a rectangular set with a bolt and a skelton key). You can reuse an old lock, but a new mortise lockset might be worth the cost (less than $20) just for the mortise-cutting template that comes with it. Before buying a mortise lock, make sure the distance from the spindle hole to the keyhole matches the one on the backplate you choose, and that the lock body isn't too thick to fit your door.

    4. HINGES

    You will likely need three to hanadle the weight of a solid-wood door or solid-core door. Many doors come with instructions that indicate the size and number needed.


    If necessary, for drilling for a cylinder lock. Tool companies make these kits, which come with two different hole saws that attach to a drill, along with a jig to guide where the holes go. Some kits also include a drill-mounted router bit and jig for carving out shallow mortises for the lock's faceplate and the strike plate.


    To hold the door in its opening as you check the fit and mark for hinges.