Most of the time, hanging prehung doors is the first stage of finish carpentry. The painters prime the walls and the trim carpenters get the house to themselves. The goal is to stay ahead of schedule and set the next stage up for easy trim install.
It seems like a lot of problems during the finishing stages of a project have to do with doors. It's hard to estimate how long it will take a carpenter to install a door correctly. Time is wasted while installing casing because the top corners of the jamb are not flush with the drywall, and worse, when it's time to install the latch set, the components don't line up. In the end, it results in call backs for doors that are not functioning properly.
I have been taught many different ways of hanging a door. It seems like everyone wants the same outcome. Plumb, square, perfect reveals and a door that closes flat against the jambs rabbit. Yet every carpenter does it differently. Old guys would always say “It's all experience. You learn to get a feel for it.” Then they would hang it slightly different every time.
Any task in finish carpentry is at its most efficient if it’s broken into repeatable steps. Door hanging has to be consistently done this way.
Carpenters have plenty of excuses for improperly hung doors . Some of the best would blame the hinges,“They don't make em like they used to.” Many talented carpenters will blame the cheap hinges and the heavy door. They will just accept a wide reveal above the top hinge and a tight reveal under the bottom hinge. “As long as it's not binding it’s ok. There’s not much you can do.”
After this article you won't need to make anymore excuses. You won't be frustrated with tough miters while casing and all your latch sets will work flawlessly.
1) Get To Know Your Door and Opening
Get To Know Your Door
-Measure the door O/D and check the swing direction. Make sure it’s the right door for the opening.
Get To Know Your Rough Opening
-Check the floor for level. If it’s out more than a ¼” you may need to shim the door higher on the hinge side.
-Set up a laser or plumb bob. Strike a parallel line to the opening. This allows you to set up a laser square to the opening, providing a more accurate line. If your laser doesn't have a square line you can just lay a framing square against the level and strike a square line.
-Set up the laser square to the opening with a 2” offset from the bottom of the jamb.
-Check the opening for plumb and if your door will still fit after shiming.
2) Pre-shim The Top And Bottom Of The Hinge Side
Pre-shim The Bottom
-Drive a screw at the bottom of the rough opening and leave it proud the amount you need to center the door in the opening.
For rough openings 2 ½” oversized, leave the screw head ⅜” off the framing. Keep the screw within ¾” of the edge of the framing and a ½” above finish floor.
Pre-shim The Top
-Drive a screw at the top of the opening.
It’s height should line up with the head of the doors jamb. This will allow you to shim against it without flexing the jamb.
-Measure the bottom screw to the laser and adjust the top screw so it is equal and plumb.
Place Your Door At The Right Height
-Lay two shims down that will bring the door to its appropriate height.
This shim thickness is found by adding the finish floor dimension and the desired gap under the door. (Most builders like a ½ ”gap between the door and the finished floor), then subtract the excess jamb length (how much the jamb runs longer than the bottom of the door, usually 1”).
Don't worry about leveling the shims. It's easy enough to remove the shim and adjust the latch side up or down.
*Note if two or more doors are beside each other, your going to want to find the highpoint of the floor and shim their heads all to the same height. This keeps the casings aligned so your eye doesn't catch anything out of level.
-Lean the doors bottom into the opening and remove the plug or nail that keeps it closed during shipping.
-Lean it all the way in and drive a shim or two into the top of the latch side. This will push the jamb plumb against your screw shims on the hinge side.
-Open the door and shim under the front of it to support it while it’s open. I use a shim bag but a scrap of plywood and a shim will work too.
3) The 5 Fasteners
-Flush the top of the hinge side up with the drywall and drive one nail into the top of the rabbit.
Make sure this is nice and flush. This step saves valuable time when casing the door later in the project.
-Flush the top of the latch side to the drywall and drive one nail into the top of the rabbit.
-Make sure the bottom is tight against your screw shim. This will ensure your jamb is plumb top to bottom.
-Flush the jamb with the drywall and drive one nail into the rabbit 1 ½” up from the floor.
-Shim the jamb off the bottom of the opening slightly and flush the jamb to the drywall.
Check that the door closes flat against the rabbit. Adjust as necessary. If the door is way out of wind, you can fix this by kicking the bottom of the hinge side in or out and splitting the difference.
-Drive one nail into the rabbit 1 ½” up from the floor.
Do not go through the shim. You will still need to adjust this side to the door later.
-Drive a nail above and below the top hinge. Drive a 3” trim head between the top of the hinge and the rabbit.
This should flex the jamb, slightly pinching the door when it’s closed. The two nails hold the screw from over flexing the jamb. This step is important. It picks up any slop in the hinge and on heavy doors this slop can mess up all your reveals. This step gives you control of the top hinge reveals.
4) Remove The Hinge Center Screws
This step is only for doors with screws that haven't been ground off and are sticking out of the other side of the jamb.
-Remove the center screws on all the hinges.
This gives you room for a shim without grinding the screws down before the install.
5) Shim the bottom hinge reveal
-Drive a shim behind the bottom hinge.
Watch as the bottom hinge gap opens nicely to your desired reveal. This only works if the bottom of your jamb is securely fastened (fastener 3). I snug a shim in and add additional nails.
5) Shim the top hinge reveal
-Drive a shim behind the top hinge.
Watch how the gap opens nicely to your desired reveal.
This only works if you overdrive your fasteners, causing it to flex the jambs slightly (fastener 5).
You may need to adjust this screw to in or out.
6) Shim The Middle Hinges Straight
-Drive a shim behind the middle hinge until it's inline with the other hinges.
You can use a straight edge or by feel and watching the reveal. Usually when the door is open it holds the middle hinge in line and you can just snug a shim in.
-Nail off the jamb side.
Make sure there is a nail above and below each hinge and one through the face of the jamb.
7) Fit The Latch Side To The Door
Adjust The Head Reveal
-Close the door and check the head is level and the reveal is nice.
If it's out you can pry the latch side up or down.
Shim The Latch
-Adjust the shim at the bottom of the latch side so the reveal is equal to the top. and nail through the shim.
-Slide a shim just under the latch mortise. Drive a 3” trim head screw just above the shim in the bottom corner of the latch mortise.
Check the reveal with the door closed. Adjust the shim and screw to the desired reveal.
-Add another nail through the jamb jace
-Shim the top third of the jamb to the desired reveal and nail it.
8) Cut The Shims Off And Clean Up
-replace all your hinge screws.
-Check that all the fasteners are in.
-Trim off your shims with a multi tool or a japanese handsaw. I wouldn’t knife them or break them, It justs prys the jamb away from your nails and weakens the install.
I just went into great detail on every step and how I personally do it. You might be thinking all those steps are overkill. Sure, you could probably feel your way through hanging a 6’8” hollow core but when you start hanging solid core and/or tall 4 hinged doors you will be frustrated or forced to make compromises.
I just hung a 9’ x 4’ front entrance. It was stain grade so I didn't use my 15 gauge and I hid my screws behind the weather stripping. I was successful because I followed these essential steps to door hanging, and then adapted my process to the job at hand.
1) Get to know your door and opening
2) Pre shim top and bottom of hinge side 3) The 5 fasteners 4) Remove the hinge center screws 5) Shim the bottom hinge reveal 6) Shim the top hinge reveal 7) Shim the middle hinges straight 8) Fit the latch side to the door 9) Cut the shims off and clean up
One More Great Reference To Understand Prehung Door Installation
This video from Garry Katz is amazing and is all you need to know when installing a 6'8 hollow core. The extra information I gave you should keep you sane when it comes to those big tall heavy doors or terrible framing.
The big difference between Garry and I is he uses wood to pre-shim the jamb (bringing in the opening) instead of screw jacks. Garry Katz is a legend and this video inspired me to make this detailed blog
I hope you enjoyed this post and maybe your reveals will finally be even.
Thank you for reading.
After filming this video I designed a tool pouch that meets my needs as a finish carpenter. It's the perfect size and is modular/customizable.
Come check it out! Click the pic below for more information.