Pre-hung doors come complete with their own jambs, making installation simpler than with slab doors. Still, a level and plumb bob will need to be used in order to ensure an opening is plumb and level.
In this article, you’ll learn five effective solutions for pre-hung doors that will leave a stylish and functional doorway ready to weather any storms that come your way.
Before hanging your new pre-hung door, use both a level and tape measure to ensure its frame is both plumb and square. If your wall framing was built using standard sizes with just drywall on top of them, shims are likely not needed for installation.
But if your house was constructed with uneven framing, shims will likely be necessary in order to correctly fit a door frame into its opening. Shims are thin wedge-shaped pieces of wood used to fill gaps or level surfaces and ensure an even surface.
Start by applying shims to the hinge side of the frame to level it and create an even 1/8-inch gap along its top portion. When attaching latch side shims, adjust as necessary until reveal is uniform across top jambs; finally nail through these shims into the wall beneath.
Installing a pre-hung door will make the installation process quicker and simpler, yet still require basic carpentry knowledge and skill for completion correctly. When installed on an exterior door, installing prehung doors will help prevent weather damage over time, saving both time and money in the long run.
Before installing a pre-hung door, it is essential to test its fit by sliding it centered in its opening and inspecting each side for plumbness. If your new door is wider than existing frames, shims may need to be added either on hinge side or lock stile to reduce opening width and maintain plumbness.
Apply shims between the wall framing and latch-side casing of the frame several inches below the top of the door frame, and centering of your bubble with a level. Nail the latch-side casing onto the frame using 8d finish nails every 18 inches around its perimeter.
Pre-hung doors should fit securely to their frames without sticking out or swinging loosely, providing an even gap of at least 1/8 inch at the bottom to protect trim and framing from water damage.
Before installing your new door, run a bead of caulking around its edges to seal off water penetration. Be sure to apply two more thick layers at both the bottom of the doorway where exterior trim will reside and along the floor surface where threshold will reside.
Install the door into its frame while ensuring its shipping brace remains attached, then use a level to check its jambs are plumb and square with the wall. Shimming side jambs may be necessary in order to accommodate for opening dimensions; however, typically no need is required in terms of top door jamb shimming as casing will keep it secure. Also make sure the king stud and trimmer stud are both level.
Installing a new door is an affordable and simple way to update your home, yet can be challenging when attempted as a DIY project by novices. Even pre-hung doors may still need some adjustments for them to hang straight and be secure against drafts.
Maintain a uniform 1/8-inch gap around the frame to ensure optimal functioning of your door. You can do this by aligning it with its frame, using a tape measure to verify both diagonals are square, and adding or subtracting shims as necessary until gap centers.
One common problem can occur when the hinge-side gap tightens over time, causing hinge knuckles to rub against the door handle and reduce door swinging without incident. A crescent wrench or similar tool may be useful in opening this gap by bending jamb-side hinge knuckles towards the handle – this will reduce chances of accidental door dings while swinging.