Installing and Replacing Doors
- Removing an Existing Door
1. Take the door off the hinges or tracks.
2. Remove the door casing (trim) on both sides.
3. With a reciprocating saw or mini-hacksaw, cut through nails holding the jambs.
4. If the door has a threshold plate, pry or cut it loose.
Framing a Rough Opening
On exterior and load-bearing walls you'll be removing a few existing wall studs that support the house. Therefore, the door's rough opening framing must take over the load.
In most cases, 2x4 or 2x6 lumber is used for side framing and two 2x10s (or larger) lumber makes up the header. Mark the outline of the doorway— 6" wider and 3" higher to accommodate framing. Make sure to remove any baseboard in the way.
Saw or chisel away the existing wallboard or plaster. Cut away the existing wall studs in the new opening below where the top of the framing header will be, or remove them completely if the header reaches the wall's top plate.
Remove the sole plate at the threshold. A reciprocating saw or hand saw is handy for this job. Cut two 2x4 (or 2x6) king studs to run the full length of the wall, or use an existing wall stud if possible.
Scab trimmer studs on to the king studs to support the header. Cut and fit the header on the trimmer studs and toenail the header to the king studs.
Installing a Pre-Hung Door
If you're putting in a pre-hung door, fitting the door into the jambs is already done for you. It works best to install the entire unit (jambs and door) at once.
Set it in the opening and use shims on either side of the head jamb to squeeze the unit into the opening. Then make sure that the hinge-side jamb is at least level (or perhaps a little higher than) the strike-side jamb. Shim underneath the hinge jamb if it is not.
With the door open, shim the hinge-side jamb until it is straight and plumb. Use a long level and shim behind the hinges. Always use a pair of shims pointing in opposite directions to create a flat surface. Nail through the jamb, through the shims, and into the framing.
Close the door and shim under the strike-side jamb until there is an even gap between the door and the head jamb (meaning that the head jamb is level). Shim behind the strike-side jamb until it is also straight and plumb. Use the door itself as a guide, shimming until there is an even gap between the door and the strike-side jamb. Nail through the jamb and shims and into the framing. Then shim and secure the head jamb.
To firmly anchor the door to the framing we usually remove one of the hinge screws in each hinge and replace it with a screw long enough to reach well into the trimmer stud.