Prehung doors differ from slab doors by including hinges and frames for mounting them with near-perfect alignment for free swinging and closing action.
Beginning by placing shims above the screws on the latch side of the frame, use your level’s bubble level and add more shims as necessary until your frame is plumb.
The Rough Opening
Pre-hung doors come complete with jamb and frame attachments, making installation much simpler than with unmounted single doors requiring hinges for mounting.
Before beginning the installation of your new door, it’s essential that the rough opening is appropriately sized. Framing doesn’t always line up perfectly square or level – leaving a little extra space can help ensure a successful and smooth door installation experience.
To determine the size of your rough opening, remove any interior casing trim from around the existing door and pry out with a painter’s pry bar. Measure both widths at center and both sides using a tape measure; record measurements from floor level up to sill height on both sides, writing down dimensions as you go.
Prehung doors contain two jambs: hinge side and latch side. They’re usually secured together at both their heads and inside corners with nails; to unfasten these use a pry bar to loosen and remove casing from both sides of opening using level as guide; then add shims under level’s bubble until both are level; this should bring all jambs back together again.
Before ordering a pre-hung door, take note of its handing (inswing or outswing) and swinging (right-hand or left-hand) to help guide your selection process. Also keep track of wall thickness (the sum of wall studs plus sheetrock), to help match jamb width to size of opening. Nail temporary cleats to walls opposite rough openings to act as stops when installing frames; additionally shimming jambs against both wall studs and against each other will help as well.
Pre-hung doors are ideal for replacement purposes or as the primary door in new construction projects, offering versatility of style, finish and color choices. Two main prehung door styles exist – frame or slab doors. A slab door does not include a frame while prehung doors contain hinged frames which fit around jambs to support and anchor them securely.
Preparing to install a prehung door requires first removing its interior casing and trim using a pry bar without damaging anything, then measuring its bottom width between studs using a tape measure in accordance with its frame or slab requirements for your new door.
As well as selecting your new door’s swing direction – is it opening into the room or out into the exterior – you must also establish its swing path. One simple method we’ve found for doing so is placing one’s nose near its hinge pins and seeing which way is more comfortable when grasping its handle.
Prehung doors provide homeowners with an effortless solution, eliminating the hassle and time involved with creating frames, purchasing wood slabs, marking, cutting and installing doorknobs and locksets themselves. However, prehung doors must still be carefully examined to ensure proper functioning; prehung door must still be checked for conditions like swing and fit before installation begins to ensure smooth performance and secure closing action.
To ensure the new door is level and plumb, have someone hold it while you insert shims under it on both hinge sides – this should result in a level bubble between trimmer and wall studs on hinge side and across from it on latch side.
Once all the shims have been installed, hammer finish nails at each location of shim. Check your reveal using your level to achieve an even surface and add more shims if necessary for uniform appearance. When completed, nail through all shims to attach top and latch sides of frame.