Many DIY enthusiasts find installing a pre-hung door to be a challenging task that may seem best left to professionals. While making the door functional is achievable, ensuring it is plumb, sturdy, and aesthetically pleasing can be daunting. Quality doors can be costly, and you want to avoid any mistakes that could waste time and money. However, with the right tools and a patient approach, you can achieve flawless results by following these tips and tricks for DIY installing a pre-hung door. This project can be straightforward if you commit to accuracy.
Once you have your door and are ready to begin, choose your tools wisely. A popular trick among DIYers is using a door installation kit, such as the E-Z Hang installation kit. These brackets attach the door jamb to the studs with a sliding system that eliminates the need for shimming, providing a helpful shortcut for novices seeking flawless results.
If you prefer the traditional installation route, gather some shims, a drill, 2 ½-inch or 3-inch construction screws, a 4-foot or 6-foot level, and a hammer or brad nailer with 2 ½-inch nails. While this can be a one-person job, having a helper hold the door in place as you secure the sides can be beneficial, along with a second pair of eyes to help avoid common mistakes.
Check the floor and the door’s fit to make adjustments
When assessing the rough opening and determining the door’s fit, check for a level floor. If the floor is uneven, the jambs won’t rest evenly, affecting the head jamb’s alignment and the door’s ability to close. Use a level on the floor just in front of the frame to see if adjustments are necessary.
If the hinge side is lower, use a shim to raise the level until the bubble is centered. Mark the required height and either raise the hinge side with shims underneath or cut the same amount from the opposite jamb (the strike side). If the latch jamb is lower, no action is needed at this time.
Dry fit the door in the rough opening to assess where shimming is necessary and if any trimming of the door jamb is required. Check for significant gaps between the stud and jamb that require more than two shims. Remove the door and adjust the opening as needed. For large gaps, add wood blocks (e.g., 1-by-4 pieces) to the stud to bring mounting points closer to the door jamb. If adding blocks on the hinge side, place them where the hinges will sit for later shimming.
Add shims to level the door frame and line up your pre-hung door
With the floor resolved, level the hinge side of the rough opening for a straight installation. Place a level against the stud (starting at the bottom) to check if it’s plumb. If not, place shims behind the level until the bubble is centered, using opposing tapers to maintain a parallel face to the stud, avoiding twisting the door jamb when secured. Adjust the thickness by sliding the shims closer or further apart.
Nail the first set of shims into place, then move the level up the stud and repeat the process at the middle and top hinge locations. Place the door in the opening to check your work. Ensure the hinge jamb is firmly against the shims and level. Use your level as a straightedge to look for gaps indicating warps in the frame, adding shims as necessary. If the door slab is attached to the frame, open it 90 degrees and slip shims under it to keep the frame level while working alone.
Make the door flush with the drywall
When positioning the door in the rough opening, ensure the jamb is flush with the drywall to avoid issues during door trim installation. A simple method is to tack a board across the doorway near the top and push the door frame until it’s snug, confirming the jamb and drywall are level. Alternatively, place small blocks (e.g., 4-by-4 plywood pieces) around the perimeter to make the jamb flush at multiple points, avoiding shimming areas.
Optionally, install blocks on the door’s opposite side to lock the frame into the rough opening, simplifying handling. Use only a few wood pieces on each side, ensuring they cover the jamb but not the door to allow for opening and closing during the project.
Screw your door to the studs
Secure the hinge jamb, starting at the top where it is flush with the wall. Work down the jamb, adding nails at hinge locations over the shims, checking for plumb alignment. Fix the jamb securely with construction screws at each hinge shim set, drilling straight through the door stop and shims into the stud. Drill pilot holes to prevent wood splits and enhance joint quality. Use a countersink bit for smooth screw holes, allowing for wood filler and paint coverage later.
Alternatively, secure screws through the hinges, a common method for pre-hung door installations. Remove the middle screw from each hinge, replacing it with a longer screw that penetrates the jamb, shims, and stud. Use a screw matching the hinge color for concealment, drilling through the hinge hole closest to the stop for the best anchor into the stud without overtightening.
Finish on the latch side
After securing the hinge jamb, move to the strike jamb, using the reveal (the slim gap between the slab and jamb) as your guide. Aim for a roughly ⅛-inch reveal. If the hinge side is perfectly level, an even reveal at the top and latch sides indicates correct installation.
Check the top jamb’s reveal, adjusting the latch side with shims or trimming to achieve even spacing. Secure the latch side with a nail at the top, then shim as needed to perfect spacing and prevent future door sticking. Nail the shims into the studs once level and adjusted correctly.
Conclude by removing excess shim material protruding past the wall, either with a multitool or by scoring with a razor and snapping off. Install the doorknob and strike plate, then complete the job by fitting the trim, filling nail holes, and caulking seams for a flawless finish. Use paintable acrylic latex caulk for the best final appearance.
