When ordering a pre-hung door, you will have the choice of a right- or left-hand swing, as well as having the manufacturer drill the holes in the door for the locksets. If the unit arrives with a brace to keep the door and frame aligned, leave the brace on until the door unit is plumbed, shimmed and secured into place. DK - Do It Yourself Home Improvement, 2009 Dorling Kindersley Limited Trim any excess drywall around the doorway to make sure the new door will hang plumb. Mark for any shims that are needed under the level. Measure and mark against the jamb where any shims are needed. Cut the door to the appropriate length. Remove the plug that comes on the pre-hung door, as well as the temporary trim on the bottom of the door. Tack one nail on a shim in the doorway to get started. Place the door inside the opening. Position the door so it is plumb, and the door is able to swing open. Secure the jamb with nails along its length. Use a straight edge to check the door opening, ensuring that it has room to open and close (Image 1).
With the door closed, place a shim by the bottom hinge to accommodate any adjustments (Image 2). Also, check the door again to make sure it is level. Check the center shim and the gap to make sure the door is plumb. Nail the door in place, from the jambs through the shims. Use a nail set to set the nails beneath the wood, creating a smooth finish. Fill the holes with spackle. Check the door to make sure it opens and shuts properly. Place a level on the vertical surface to check that the door is plumb (Image 1). If you need to adjust the door, try using a sledgehammer with a very gentle tap (Image 2). If your doorframe is damaged, you need a pre-hung door, which includes the frame and door. If your frame is in good shape, a slab, also called a blank door (image to the right), is fine. Whichever type you use, there are a variety of styles available to match your home decor. If you're installing a pre-hung door, make sure you get the correct swing, determined by the placement of the hinges and doorknob.
Open the door and stand with your back to the hinges. If the doorknob is on the left, you need a left-handed door. If the knob is to the right, select a right-handed door. Some blank doors have a specific swing direction. The strike side (the side with the lockset) of these doors has a beveled edge so the door can swing freely. The steps below describe installation of a blank door. Good to KnowWhen buying a new door, choose one that's the same size as the old one. Removing the Old Door You can use your old door as a template to install the new one. Before removing the old door, close it and make marks 10 inches up from the floor. You'll use these as reference marks later to trim the new door. Good to KnowPurchase hinges that are the same size as your existing hinges. Remove the old lockset and hinge pins, and take out the door. Remove the hinge plates from the door as well. Good to KnowYou can use a flathead screwdriver and a hammer to tap up the hinge pins for removal.
Marking and Trimming the New Door With the new door on sawhorses, set the old door on top — keeping the tops and hinge sides flush — and clamp in place. Mark any excess on the new door. You'll trim it off later. Use a combination square to mark the locations of the hinge mortises on the new door. Use the square to transfer the distance of the mortises from the door edge. Mark the mortise depths using a hinge as a guide. Mark the lockset location. Transfer the 10-inch reference marks you made above from the old door to the new one. Set the old door aside. From these reference marks on the new door, measure 9-7/8 inches toward the bottom and make a straight line across the door. This line shows you where to cut for a 1/8-inch clearance at the bottom of the door, Cut any excess from the sides and bottom of the new door with a saw or planer. Check the door manufacturer's instructions for cutting recommendations. Good to KnowWhen cutting, remember the strike side of the door may be beveled — don't cut the beveled edge.
Attaching the Door Hardware Door hinges may be rounded or square. If your hinges are rounded, you can use a router with a hinge template to cut mortises. If your hinges are square, you can cut the mortises with a chisel, using the steps below. Score the mortise lines you made in Steps 2 and 3 above with a utility knife. Use a chisel and hammer to outline the edges of each mortise and make relief cuts across the area. Don't go deeper than the mark you made in Step 4 above. Chisel out the wood inside the marks. Keep the beveled side of the blade down to remove only small amounts of material. Watch our DIY Basics video: How Do I Use a Chisel? At each mortise, hold the hinge in place. Drill pilot holes and attach the hinge with screws. See How to Drill a Pilot Hole to learn about pilot holes. Drill the lockset holes according to the hardware instructions. Cut only halfway through one side of the door. Flip the door over and finish the holes from the other side.
This technique helps prevents splintering. Good to KnowA door lock installation kit or drill guide (pictured above) simplifies lockset installation. Drill the edge-bore hole for the latch with a 1-inch hole saw. If you plan to paint the door, it's a good idea to do it now. On the jamb, install the new hinge plates. Check the fit of a plate by holding it in a mortise. It should be flush with the casing. Good to KnowIf the holes on your new hinge plates don't match the holes in the screw holes in the door jamb, drill pilot holes for the new screws. If the holes in the jamb are too large for the screws, use wood glue to secure a short portion of dowel tightly in the hole. Allow the glue to cure and drill the pilot holes. As an alternative, you can use longer screws to fasten the hinge plate — just make sure the pilot holes will accommodate them. If a mortise isn't deep enough, remove some wood with a chisel. Remember to keep the beveled side of the chisel against the wood to remove small amounts of material.
If a mortise is too deep, use cardboard as a shim behind the hinge plate (as pictured to the right). Once you have a good fit, attach the hinge plates with screws. Attach the new strike plate if you're not using the old one. Set the door in the hinges. Use wood shims on the floor to elevate the door if necessary. Insert the hinge pins. You can use a hammer to tap the hinge pins flush if necessary. Good to KnowIf you have trouble getting the hinges to line up, loosen all the screws. The excess play will help the hinges slide together. Insert the pins and retighten the screws. Test the door by working it back and forth. You should have about 1/8 inch clearance at the header and strike sides, and 1/16 inch clearance along the hinge side. Remove the door to make any adjustments. Install the lockset or door knob according to the directions. Look at to How to Install a Lockset for general steps. Test the door to make sure it fits and swings freely. Watch our DIY Basics video: What's Wrong with My Door?