Interior doors develop a small set of recurring problems: squeaky hinges from dried-out lubricant, sticking or binding from seasonal wood expansion or shifted framing, loose hinge screws that cause the door to sag, and worn locksets that no longer latch properly. Most of these are 15-minute fixes. A squeaky hinge needs a drop of silicone lubricant or white lithium grease on the pin. A sagging door usually has one hinge with stripped screw holes — replacing the short screws with 3-inch screws that reach the structural stud behind the jamb pulls the door back into alignment. A door that sticks along its edge in humid months can be planed or sanded slightly rather than re-hung.
Close every interior door in your home and check for problems: does it latch cleanly, swing freely without rubbing, and sit evenly in its frame? Most issues are visible as uneven gaps between the door edge and the jamb. Fixing the most common problem — a sagging hinge — requires only a screwdriver and a single 3-inch screw, making it an ideal first repair for building confidence with household fixes.
Interior door problems cluster into a predictable set of failure modes, each with a signature symptom and a matched repair. The diagnostic step is always the same: close the door fully and inspect the gap between the door edge and the door frame (called the jamb). In a well-hung door, this gap is even all the way around — roughly the width of a nickel. Uneven gaps tell you exactly what is wrong and where.
If the gap is wide at the top of the hinge side and narrow or rubbing at the latch side, the door has sagged. Sagging is almost always caused by loose hinge screws, not structural failure. A door hung on three standard ½-inch screws is supported by very little material — those screws bite only into the jamb's thin casing, not the structural framing behind it. Over years of use, the screws work loose, the hinge tilts slightly, and gravity pulls the door down and outward. The repair is counterintuitive in its simplicity: remove one of the hinge screws from the top hinge (the one bearing most of the door's weight), replace it with a 3-inch screw, and drive it all the way through the jamb into the stud behind it. That single screw reaches solid wood and pulls the hinge — and the top of the door — back into alignment. From your furniture assembly experience, you already know how dramatically anchor depth affects holding strength; this is the same principle.
If the door sticks along an edge seasonally — especially in humid summer months — wood expansion is the likely cause. Wood is hygroscopic: it absorbs moisture from the air and swells when humidity rises. A door that closed perfectly in February may drag against the frame in August. Light sanding or planning along the binding edge (the side opposite the hinges) removes just enough material to restore clearance. Sand only the amount needed; the gap will return in dry months when the wood contracts.
Squeaky hinges are the simplest repair of all: the metal-on-metal friction of the hinge pin against the barrel needs lubrication. Silicone spray or white lithium grease applied to the pin and the barrel knuckles quiets the squeak immediately and lasts for years. Apply it while moving the door back and forth to work the lubricant into the joint. A worn latch that no longer catches the strike plate is usually a vertical alignment issue — the latch bolt misses the strike plate hole because the door has settled. Before replacing the latch, check whether elongating the strike plate hole with a file resolves it; if not, the strike plate can be remounted slightly higher or lower with a chisel to deepen the mortise.