Sagging doors have gotten complicated with all the “plane the door” advice and hinge shimming tutorials flying around. As someone who has fixed more sagging doors than I care to count — in my own house and others — I’ve learned what the actual cause usually is and the fastest path to fixing it. Today, I’ll share everything I know.

How to Fix a Sagging Door

Diagnosing the Cause First

Before touching anything, open and close the door slowly and watch where it contacts the frame. A door that drags at the latch side corner is almost always a hinge problem — either loose screws or worn hinge hardware. A door that sticks along its full length usually indicates wood movement from humidity changes, which is a different fix entirely. Diagnosing correctly saves you from doing the wrong repair.

Tools Required

For hinge-related sagging: a screwdriver matched to your existing hardware, a cordless drill, wooden toothpicks or wooden shims, wood glue, and a level. That’s it for most cases.

Checking and Tightening the Hinges

Start simple. Open the door and check every hinge screw by hand. Loose screws are the most common cause of sagging and the easiest fix. Tighten all loose screws. If the screws turn without biting — the holes are stripped — that’s the actual problem. Remove the hinge leaf from the jamb, fill the stripped holes with toothpicks or a wooden shim dipped in wood glue, let the glue dry completely, then reinstall. The wood filler gives the screws something to bite into again. This fix works reliably and lasts for years.

Adjusting the Hinges with Cardboard Shims

If tightening doesn’t solve the problem, the hinge may need to be repositioned slightly. Unscrew the hinge leaf from the door frame side. Cut a piece of cardboard to fit behind the hinge, place it, and reinstall. This shifts the door position relative to the frame. Adjust shim thickness until the door swings freely and sits square in the opening. I spent a Saturday afternoon doing this on a bedroom door that had been dragging for years — took about twenty minutes once I understood the geometry.

Using a Wooden Shim for More Significant Adjustment

For cases where the door sits noticeably low, a wooden shim between the top hinge leaf and the jamb raises the latch-side corner. Remove the top hinge jamb leaf screws. Wedge the shim in, insert one screw to hold, then check with a level. Adjust shim thickness until the door is plumb and swings without dragging. Once you have the alignment right, install all screws and do a final open-close check.

Final Check

Open and close the door repeatedly. It should swing freely without catching anywhere and close snugly against the stop without needing to be lifted. Check that the latch engages cleanly — a properly aligned door’s latch lines up with the strike plate without forcing. If it doesn’t, the strike plate can be adjusted by filing the opening slightly or by relocating it.

One Final Thought

Most sagging door problems resolve with the stripped screw fix or a cardboard shim — fifteen minutes of work that homeowners avoid for years because the problem sounds more complicated than it is. Check the hinges first. That’s where ninety percent of the answer is.