STEP 3. Attach the Door Installation Brackets to the Door Jamb. To start the installing interior door, place a door installation bracket behind each of the 3 or more. Problem free Prefit Doors THISis. Carpentry. Ive been hanging doors for over thirty five years, and writing about it for nearly twenty five. For many years, I approached door installs differently every time like most carpenters. After all, there are so many steps, and there is a lot you need to watch for Its tough to do it the same way every time. But a door is a door is a door. Which means unless youre doing exactly the same thing every time you install one, youre wasting valuable energy and time. In this article, Ill break down door installation into the most important stepsthe first five fasteners. But always prepare the opening before you attempt to set the jamb. Prepare the Opening. Rough openings are exactly thatrough openingsespecially today when framers often frame them more than 2 in. And floors are almost always out of level, too. And walls are frequently cross legged. Images/Corinthian/Door%20Systems/Prehung/PreHungKit.jpg?bc=White&as=1&h=414&vs=1&w=552' alt='Install Split Jamb Prehung Interior Door' title='Install Split Jamb Prehung Interior Door' />Before you attempt to set a jamb, be sure to correct all those problems or theyll become bigger problems later. Correct Cross Leg. If you set a jamb into an opening with cross legged walls, the door wont lay flat against the jamb and the door stop. You might even think the door is warped, when it isnt. There are two ways to check for cross legged walls. Drive a nail or screw into each corner of the rough opening, then run a string around the four screws, creating an X at the middle of the doorway. The two strings should touch each other at the X. If they dont, try to move the walls at the bottom of the openingjust a little. Note Click any image to enlargeUse a small sledge hammer and a block of wood, and tap the bottom of each wall lightly. JELDWEN guides you through the steps of preparation and installation of a prehung interior door including a recommended list of tools. How to Hang a Prehung Door. Prehung doors are doors that come from the manufacturer installed in a door frame. Prehung doors are purchased with the hinges attached. Before banging on a wall, check to be sure theres no plumbing fixtures or electrical outlets. Amos Software Mac here. And look around the back side of the wall for tile, too Dont worry about getting it all. You can correct for cross legged walls when you set the jamb, too. You can also check for cross legged walls by cross sighting a jamb. If the jamb isnt at the end of a narrow hallway, stand to one side of the rough opening and sight across the edge of the jamb nearest you to the opposite edge of the jamb farthest from you. How To Install Split Jamb Prehung Interior Doors' title='How To Install Split Jamb Prehung Interior Doors' />Level the Floor. Dont wait until the jamb is in the opening to level the floor. Its too difficult and awkward to hold a level over your head while youre trying to nail the jamb flush with both sides of the wall. Instead, place a level on the floor and shim it until the bubble is centered in the vial. If youre installing the door on a finished floorlike stone, tile, or hardwoodyou can measure the thickness of the shim and cut that amount off the opposite leg. If the flooring isnt installed, leave the shim in place and set the jamb on top of it. Shim the Rough Opening. Most rough openings are framed too big and must be shimmed in before setting the jamb, otherwise piles of shims must be inserted between the jamb and the framing. Use plywood squares to shim in the rough opening so that the corrected rough opening is 18 in. But do not shim behind the hinges. Shimming behind the hinges before setting the jamb will prohibit you from making critical adjustments to hinge gaps and will prevent you from making necessary adjustments to strike gaps. Install Split Jamb Prehung Interior Door' title='Install Split Jamb Prehung Interior Door' />Pin the Door in the Opening. Place the jamb in the opening, then remove the fastening screws or temporary latch. Insert two shims at the top of the jamb on opposite sides of the head jamb. These two shims will safely secure the jamb and the door in the opening. The First Five Fasteners. Install the first five fasteners in precisely the correct locations and in exactly the right order. Otherwise, you may not be able to adjust the door properly. Move the bottom of the hinge jamb in or out of the wall until the door is lying flat against the strike jamb. If the jamb is severely crosslegged, dont try to. Tom Silva does a plumb job putting up a prehung door. DEAR TIM I need to know how to install a prehung door. This door is a regular interior door, not an exterior door. Is this job as easy as the salesman made it out to. In this instructional example, Im driving screws through pre drilled counter sunk holes in the face of the jamb. Instead, drive 1. Fastener 3 Fastener 3 must be driven at the very bottom of the hinge jamb, as close to the floor as possible. But before driving fastener 3, correct any remaining cross leg. Fastener 4 Fastener 4 must be driven at the very bottom of the strike jamb, as close to the floor as possible. But before driving fastener 4, correct any remaining cross leg. In order to maintain a consistent and acceptable strike gap approximately 18 in., you may need to insert an additional shim to back up the jamb before driving fastener 4. Fastener 5  This last fastener corrects a serious issue with prefit doorsespecially heavy prefit doors. The weight of a door will pull down on the top hinge, placing the top hinge under tension. To relieve the tension on the top hinge and jamb, replace one of the top hinge screws with a screw long enough to penetrate the jamb and the wall framing. Do not torque this screw too much or the door will be jamb bound. A slight amount of pressure on that screw will correct the top hinge gap. And in the future, that screw can be loosened or tightened to correct the fit of the door in the event the home settles. Correct the Bottom Hinge Gap. Most heavy doors will apply pressure and compress the bottom hinge, which will close the hinge gap beneath the bottom hinge. Triumph Serial Numbers Yearly Calendar. Frequently, prefit doors are not installed correctly and the bottom of the door touches the jamb, leading to the door being jamb bound. To support the bottom hinge and adjust the bottom hinge gap, install a shim just above the bottom hinge. Insert the shim until the hinge gap is equal at the top and the bottom of the door. Support the Hinge Jamb. Insert pairs of shimsone from each directionabove and below each hinge, and every 1. Shim the Strike Side and Head. Do not drive fasteners near the lockset or deadbolt locations. Shim the head jamb so that the head gap is even across the top of the door. Click here to read a related article, Installing SidelightDoorSidelight Units. How To Install A Prehung Door. DEAR TIM I need to know how to install a prehung door. This door is a regular interior door, not an exterior door. Is this job as easy as the salesman made it out to be I am suspicious, as it seems that you need some good skills to install a prehung door. What can you share so that I might have a fighting chance as I wrestle with this door Bill F., Greeneville, NCDEAR BILL Installing a prehung door is not a job I would entrust to a rookie carpenter. The job is fraught with all sorts of little challenges that are solved with tricks that come with lots of experience. To end up with a door that fits perfectly without rubbing, you need to know some of these tricks. In other words, the salesman either thought you were a seasoned carpenter or he needed to make a sale. No worries though, as I will try to give you as many tips as possible to help you survive this job. Tapered wood shims are needed when you are installing a door. PHOTO CREDIT Brent Walter. I am going to assume you purchased the right sized prehung door and that it is handed correctly. It is a very common mistake to purchase a prehung door that swings the wrong way. To determine proper handing, always imagine looking at the door and be on the side where the door swings towards you. If the door knob is on the left side of the door, it is a left handed door. If the knob is on the right, it would be a right handed door. Prehung doors often come from the factory with the jambs a little long. This is done on purpose so you can install the door in places where there will be carpet and not have to cut off the bottom of the new door. The goal is to have about one half inch of airspace between the bottom of the door and the top of the carpet or any finished flooring material. The door jambs dont have to touch the subfloor in carpeted situations, but they must be in contact with hardwood flooring, ceramic tile, cork or other finished floors that are typically smooth. Before the door is installed, make sure the top and bottom of the door is painted. You can just lay the door flat on the ground and open it to check to see if this was done at the factory. It is important to have the top and bottom of doors sealed to prevent warping. Prehung doors typically come from the factory with a one eighth inch gap between the edges of the door and the door jamb. The doors are almost always perfectly square, so the challenge is to square up the jamb within the rough opening so the gap between the door and the jamb stays consistent. The biggest challenge is cutting the lengths of the jambs correctly so the gap at the top of the door is correct. If one leg of the jamb is too long, you will end up with the door rubbing against the top jamb or a horribly large gap between the door and the jamb just above the door knob. It is really important for the door jambs to be installed plumb. Use a four foot level to see how plumb the rough opening is that is common to the hinge side of the door. Use wood shims with the level and tack the shims against the jamb until the level is perfectly plumb. It is best to install shims at the same height as the door hinges. Position the prehung door into position, slide it up against the shims, and see how things looks. You know you are in great shape if the gap along the hinge side of the door and the top of the door are the consistent one eighth inch. Dont worry for now about the gap along side the door knob side of the door. This is the least important jamb. Use 1. 0 penny finish nails to attach the hinge jamb of the door to the rough jamb. Carefully nail through the jamb and into the shims. Do not drive the nails completely into place. Leave at least one half inch of the nails exposed in case you need to make adjustments to the length of the door jambs or you have to move the jambs slightly in and out so the door fits perfectly. Once all adjustments are made, all shims are in place and the door fits well, then you can drive the nails home recessing the nail heads with a nail setting tool. To really add a professional touch to your installation once complete, you will want to temporarily remove the top hinge from just the door jamb. Doors are heavy and over time the weight of the door can actually pull the jamb away from the finish nails. This will cause the door to rub and not fit well. If you take a three inch long screw and drive it through the jamb into the rough jamb at this upper hinge, the door should stay put for many years. It is important to predrill the hole so you do not split the jamb and create a countersink hole so the head of the screw does not touch the back side of the hinge once the hinge is reinstalled. Some carpenters just remove one of the regular short hinge screws and replace it with a longer one that will penetrate into the rough jamb. This method will also work. When shimming the jambs, place the shims at about two foot intervals and always nail through the jamb at a location where you have installed shims.