How to Hang Pre Hung Doors

Hanging a pre hung door can be a little trickier than you think, if you have some time and a fair amount of patience you should be ok. You might think that hanging a pre hung door is as easy as sliding the thing in place and pounding in a few nails, it's not so get it out of your head right now. I've always found that if you go into a project thinking it's going to be quick and easy, the frustration level skyrockets when it becomes a nightmare project. This is one of those projects that if you are not prepared for it will get the better of you and you will eventually settle for a less than perfect outcome. The main reason for problems with this task is that the door frame 95% of the time is not square and therefore will create a crooked door if you just slide it in and pound it up.

It is true that a pre hung door already has much of the work done which is helpful but you still have some work to do and work that will involve some attention to detail. The first thing you need to check for is the level of the floor. The door manufacturer usually keeps the length a little long on each side of the jambs so you can make some adjustment if you find that the floor is not level. If you find that the floor is not level (it's usually not level) you know that the jamb legs on the high side of level need to be shortened. If you don't do this you will have one jamb leg floating in the air and this will make it extremely difficult to install. To get the door square without the stability of the jamb legs is near impossible.

The pre hung door will always be perfectly square so the trick is to space the door evenly within the door opening so it is even all the way around. You want to start the job from the hinge side out, in other words you need to make sure the hinge side of the rough opening for the door is level. If it's not you need to make measurements to figure out how out of whack it is and make a note of the measurements and write them down with the details included like which part is out or in. If you take accurate measurements you will be able to shim out the door so it hangs square in the opening.

Next you need to position the door and the jamb in the rough opening and use shims and your level to get the door as square and level as possible leaving the same gap all the way around the door. Once you have gotten the door uniform on all sides tack it up with a few nails just to keep it in the correct spot while you make your adjustments. It is important to make your door jambs flush with the finished wall on both sides. As you put in shims between the jamb and the frame (at the hinges), tack these hinges between the door and rough frame. Once you have the hinge side tacked and shimmed you need to check the top and make sure the gap across the opening is even all the way across, if it is, continue the process all the way around, shimming and tacking as you go along. If the top is not even all the way across you need to adjust the appropriate side jamb and you should be good to go. Once you get the top you want to move to the door knob jamb, it works the same way as previous, just slide shims in until the gap is consistent all the way down the jamb. Once you find that the door works properly tack the jamb through the shims.

With all the previous steps done and the door in place you need to now attach the door with screws. If you just leave it tacked up with nails you will find that over the years the door will start to get out of whack. You need to put screws in the door on all sides. Make sure while you are screwing in the first few screws that you don't skew the door that you have worked so hard to keep square. Once you have all screws in then you can go back and tighten them up if you feel the need to be. Your pre hung door should be in and operating with great smoothness. Like I said earlier it's not the easiest thing to do even though it might seem that way. Patience is one of the biggest tools you'll need for this project because there will be some things that don't go exactly right. Good Luck