Opanpan Door Skins
Knowing how to shim a door will help you resolve a number of issues with all kinds of DIY projects, ranging from the installation of an entirely new prehung door to fixing a door that’s no longer level within its frame.
How to shim a door in preparation for prehung doorframe installation
When installing a new prehung door, you’ll need to add shims between the new frame and the rough opening. Begin by sliding the doorframe into place, then use your hands or a hammer to wedge shims into place anywhere you see open space between the frame and the drywall (or other rough opening building material).
Once you’ve added your shims in all the right places, you can add the door casing that will cover up where the shims are, as well as the unsightly border between the rough opening and doorframe. Before adding your casing, cut the shims—they tend to be much longer than the width of doorframes. Shims are easily cut using a small hand or hacksaw.
To correct doors that aren’t level within doorframes
Knowing how to shim a door to correct the plumb of a door within its frame can save you a lot of time and money, especially if you’re laboring under the misconception that the entire door and frame will have to be replaced because it isn’t level.
To begin, you need to remove the interior or exterior door from the doorframe. Next, remove the hinges from both the door and the frame entirely: use this opportunity to clean and grease each hinge to ensure it slides smoothly and without any resistance. Before reinstalling the door hinges onto the door frame, place a shim right over the existing screw holes for each hinge. You can apply these to the doorframe with long finishing nails or screw them in with a power drill.
Now you’re ready to reinstall the door hinges to the frame. This time, don’t use the old screws: instead, use longer screws along with screw anchors to ensure a longer-lasting hold. Finally, reinstall the door within the frame by screwing in each hinge, beginning with the hinge in the middle, then the top hinge, and lastly, the bottom hinge. Your door should now be level within the frame. If the door still isn’t level or is still rubbing against the frame and having trouble shutting, check for door warping and swelling, which are easily repaired as well.