Installation of pre-hung doors in your house can be an effortless project that adds both beauty and utility. But before starting to hammer away, take time to double check all measurements – buildings settle over time, leading to an irregular gap around door jambs.
Utilize a level or plumb bob to ensure the gap is equalized, and add additional shims where necessary.
Level the Door
If your door isn’t level, it will stick and catch when opening or closing it. To correct the imbalance, use shims to provide equalization of pressure across its width.
Insert wedges or shims to raise the latch side of the frame in an uneven opening, until its gap with the lintel is even. After this has happened, nail the top of your door frame into place.
A carpenter’s level and tape measure will allow you to determine whether your door frame fits within its rough opening in terms of squareness. Shim the jambs if necessary for plumbness before installing your hardware–doorknob, lockset and strike plate; this step may be easier if your jambs are level and square; otherwise you’ll have to improvise. Don’t forget a sill pan!
Shim the Jamb
To keep the door swinging smoothly and avoid dings, it’s necessary to stabilize its jamb with shims. These will ensure that its frame remains flush against its surrounding stud framing.
Begin by placing shims close to the hinges on either side. Check your alignment of jamb and shims with your level, adding more shims until the gap along the top of jamb is uniform and level with wall.
Shimming and level-checking must then be repeated on the latch side of the jamb. Reduce shimming if gaps are too wide; increase it if gaps are too narrow.
Shim the Hinges
If your door hangs unevenly or rubs against its frame, adjusting its hinges might be necessary to make it run more smoothly. Doing this is straightforward with the appropriate tools.
Use a nail set rather than a hammer when tightening hinge leaves, as using either will likely leave an ugly mark in their place.
As with the jamb side, this step should be carried out for both strikes and jamb sides. First, place a suitable-sized shim behind the strike plate on hinge side – not too small nor too large!
Use a level to ensure the hinge side of the door is level with and plumb against the wall, adding shims if necessary. Finally, test closing it to make sure both hinge and strike sides close evenly before checking that all hardware has been secured securely to its respective hinges or strikes.
Shim the Lock Stile
Consider your home’s swing direction and handle placement before ordering the appropriate door to ensure it fits perfectly when it arrives.
Gently pry away the interior trim and unbolt hinges. If your new door features a strike plate, use a hammer and screwdriver to disassemble it from its frame.
Use a carpenter’s level and square to measure the width and depth of your opening, then add wood shims if it’s slightly wider than required by adding them on either the lock stile side directly across from hinge side to keep frame plumb or use wood shims on latch side to increase door jamb height. It may take two people for this step.
Shim the Door
For even spacing between door and frame, shim each hinge location on both the latch and hinge side of the frame. You may also need to shim your sill plate up or down until it lines up correctly with pre-hung door and frame.
After setting the gap correctly, use a carpenter’s level to check that the head jamb is plumb against the wall. If it is not plumb, slip shims beneath hinge side jamb until level and repeat on latch side frame until level as well. Using finish nails secure shims directly to jambs resulting in an equally level and plumb door with uniform reveal.