Installing an interior door can bring dramatic transformation to the look and feel of your home in just hours. DIYers with basic carpentry skills should not find this project too challenging, although you should enlist help from friends for lifting purposes.
If the trim and jambs are out of plumb, use shims to level them back out and use putty that matches your door frame color for best results.
Measure the Opening
Before purchasing a pre-hung door, it is necessary to determine the size of your rough opening. Remove any interior trim around the doorway, measure between door studs and record these measurements in inches. Also take note of height from floor surface to sill on both sides of rough opening.
Important measurements must be taken, because otherwise you won’t be able to install your door properly. Also important are determining whether your door swings left or right for optimal fitting within its space, known as its “handing.” Once these measurements have been taken, purchase some wood shims and finish nails to begin your project.
Measure the Jambs
If your existing door frame is still attached to the wall, remove its trim and pry loose the head and side jambs using a painter’s pry bar without damaging the wall. Use a tape measure to obtain its width by taking measurements between studs at various locations; additionally record any minimal height and jamb depth measurements that occur along each side of the frame.
If your jambs appear too low in relation to the rough opening, add shims underneath each jamb to raise them up. If the strike side of the hinge jamb seems off square, use a 6′ level and adjust its middle and lower strike sides until the bubble of level sits centered – this will ensure your new door swings smoothly.
Cut the Jambs
Before installing jambs, use a level and plumb bob to ensure that both walls and trimmer studs are level with one another. Otherwise, hanging pre-hung doors may prove impossible due to their head jambs not sitting flush against the drywall surface.
Shim the hinge side of your frame to correct for unevenness, placing a level on the floor in front of an opening and using shims underneath its bubble until your head jamb is level.
Repeat this process on the latch side of the frame. After installing shims, use your carpenter’s level to level out the frame before nailing through them to secure. Finally, check alignment of door with level, making any necessary adjustments as necessary.
Install the Jambs
To install a pre-hung door, begin by stabilizing its frame with shims on both sides. Use the hinge side as your guide; be sure to shim it at least 4 inches above the floor before checking it with a level to make sure everything is perfectly vertical.
Apply a thick bead of caulk around the bottom edge of the sill and insert the new door unit, shimming its latch side until it aligns with the stud before fastening it with finish nails. If your carpentry skills are subpar, consider calling in an expert; an experienced carpenter should be able to set up a pre-hung door within an hour – which can save time and headaches in the future!
Hang the Door
Even though pre-hung doors may be easier than slab ones to install, even for novices the task remains complex and requires carpentry skills as interior doors are heavy. Don’t hesitate to seek assistance if necessary!
Before installing your door, let it acclimate by placing it on a flat surface for three days prior to hanging it up. Be sure to protect yourself and the work area with protective work gloves and eye goggles; additionally chisel away wood that’s too thick to fit hinge recesses, marking where each hinge should go on the door.
Use a level to check that the head jamb is level, then slip shims under hinge side until bubble centers. At this stage, secure hinges using just one screw per flap.