Do you have a door that’s been lying against a wall, waiting to be installed? I have seen these unhinged doors lying around at other people’s homes and cottages. I guess thinking about the energy it will take to install the door leads many people towards procrastination regarding this project. If you’ve ever wondered how to professionally hang an interior door, well look no further. We spoke to a longtime professional trim carpenter Jerome Worm and asked him to share his professional tips for installing a door.

Naturally, you want to ensure that the door will actually fit into the opening. Measure the opening height and the width at the top and bottom. With a bubble level, make sure that both vertical sides are centered on the bubble. The accuracy of the vertical plumb will not be 100% spot-on, but as long as it’s 99%, this will allow enough space for your door.
It is important that the bottom doorjamb is at the proper height for the door opening. You’ll have to make a few on the fly adjustments if you’re installing the jamb on a finished floor that isn’t quite level. This adjustment can be achieved by cutting a little off the bottom of the jamb.
Our professional, Jerome Worm, uses a circular saw to cut doorjambs down as required. An 80-tooth saw blade is recommended for clean cuts to prevent tearing on the wood veneer. As the old saying goes, “Measure twice, cut once.” On the high side of the door, cut the jamb that rests on that area. Be careful not to cut the wrong jamb. The jamb to cut will be on the side opposite to the door opening where you marked your shim. Use a rafter square (carpenter’s marking out tool) as a saw guide for this purpose.
Before permanently fastening the door jamb flush with the drywall, Worm attaches temporary blocks to both sides of the jamb to hold it in place. Use five 4-inch or 5-inch lengths of scrap woodblocks. Using 2-inch 18 gauge brad nails, nail three blocks on the latch side and two on the hinge side. A pro tip is to keep the blocks away from the door hinges so they won’t interfere with shimming. When the blocks are removed, the casing will cover up the nail holes.
Now at this point, you may be asking, “But what if I’m installing a door on a floor that’s unfinished?” If carpeting will be installed, rest the jambs on temporary wood blocks while the door is being hanged. To make sure that jambs are on a level plane, adjust the size of the blocks. Professionals recommend a space under the jambs between 3/8 of an inch to 5/8 of an inch, but this depends upon the thickness of the underpad and carpet itself.
Ensure that you have a consistent gap between the door and the three sides of the jamb. Make sure that the door is properly centered on the opening. It’s crucial that the jambs were cut properly beforehand as this will ensure the gaps will be consistent. The result is the top will be horizontal level and the sides will be vertically plumb.
Remove the plug that holds the door in place. Make sure that the door opens and closes smoothly. This can be done once the plugs that hold the door in place have been removed. During this test phase, pay attention to the door itself as it closes and comes into contact with the doorstop. One of the most important tips for installing a door is if the door hits the stop at either the top or the bottom, you will need to adjust the jambs. You want to ensure that the door comes into the stops evenly and on all sides for its entire length. Depending upon which part of the door hits first, make adjustments to the top and bottom sides of the jamb moving it in or out as required.
Starting with the top hinge, remove the center screw from all three hinges. Fill the whole gap evenly between the jamb and the framing to prevent the door from being out of alignment if the whole gap is not filled evenly between the jamb and the framing.
Pay close attention to the jamb as you drive in the screw. Go slowly on the last few turns so that you keep the door aligned. A pro tip is to replace at least one factory screw of each of the hinges with a longer one. Keep checking the gaps, and after each screw has been installed, open and close the door to make sure that it’s moving smoothly.
You are almost finished! Insert and secure shims four inches down from the top of the door. Repeat this step four inches up from the bottom of the floor. Nail in the shims similar to how you did this on the hinge side.
Hopefully, after reading these professional tips for installing a door you are able to install your door with ease.
You might be interested in reading, “Repairs for Your Home You Can Do Yourself“.