Summer humidity hits, and suddenly the bedroom door that slid effortlessly in January now scrapes the jamb with a grating sound. You push harder, it binds further, and by August you’re contemplating planing the whole thing down only to watch it hang loose come winter. This pattern isn’t random—it’s wood doing what wood does. Interior doors stick for two main reasons: the door itself swells as it absorbs ambient moisture, or the house frame shifts slightly under seasonal loads. Knowing which one you’re dealing with saves you from removing material you shouldn’t, and the fix is often simpler than replacing the door.
Wood is hygroscopic—it exchanges moisture with the surrounding air until it reaches equilibrium moisture content (EMC). In winter, indoor relative humidity might drop to 20–30 percent, and the door’s EMC settles around 6–8 percent. In humid summer, indoor RH can climb to 60–70 percent, pushing the EMC to 12–14 percent. That 6 percent swing in moisture content causes the wood to expand across the grain—most doors are constructed with stiles and rails where the grain runs vertically, so width changes more than height.
A typical 32-inch wide hollow-core door can gain roughly 1/8 to 3/16 inch in width from winter to summer. That doesn’t sound like much, but standard door clearance is only 1/8 inch on each side and at the top. When the door swells past that gap, it binds against the jamb. The lock side is usually the first to stick because the hinge side is fixed. If you see paint rubbing off the edge of the door near the latch, that’s a clear sign of moisture-driven expansion.
Solid wood doors—especially those made from pine, fir, or oak—expand and contract more than hollow-core doors with MDF skins. MDF (medium-density fiberboard) is more dimensionally stable because it’s made from wood fibers and resin, but it swells irreversibly if it gets wet. Solid wood can cycle back and forth for decades if the finish remains intact. If your door is solid wood and sticks only in summer, planing is usually safe. If it’s MDF-skinned, sanding too aggressively can expose the honeycomb core, which ruins the door.
Before you plane the door, close it and look at the gap between the door edge and the jamb. If the gap is tight at the top but wide at the bottom, or vice versa, the frame has likely shifted. This is called frame racking—the jamb is no longer square. It happens when the house settles, when foundation movement occurs, or when a heavy piece of furniture is installed near the door opening and transfers load through the floor joists. Frame racking also appears after basement or crawl space work that changes the support structure.
To test, use a carpenter’s square or measure diagonals. Place the square in the upper corner of the door opening: if the corner isn’t 90 degrees, the frame is racked. Alternatively, measure from the top left corner to the bottom right, then top right to bottom left. If the two measurements differ by more than 1/4 inch, the frame is out of square. In that case, planing the door only masks the problem—the door will still bind when the frame continues to move.
You need to pinpoint the binding points before you touch any tool. Here are three tests that take less than five minutes total:
If the paper test and chalk test confirm the door is swollen uniformly, planing is the standard fix. But doing it wrong creates gaps that whistle in winter. Use a block plane or a belt sander with 80-grit paper—never a circular saw or a hand saw freehand. Mark the area to remove with a pencil, staying within the chalk transfer marks. Remove only as much as needed: take off 1/64 inch, test, repeat. In most cases, 1/8 inch total removed from the latch edge is enough.
After planing, taper the cut slightly so the door fits snug at the latch plate and widens gradually toward the stile. A straight cut leaves a visible gap when the door dries in winter. Seal the raw wood immediately with primer and paint or polyurethane. Unsealed wood will reabsorb moisture and swell again within weeks. For hollow-core doors with veneer, use a fine-tooth rasp rather than a plane to avoid chipping the veneer edge.
If the binding is isolated to one corner—say the top latch corner—the door may simply be tilted in the frame. This is common after carpet replacement or floor refinishing that changes the floor height. The fix is hinge adjustment, not door planing. Remove the hinge pin, lift the door off its hinges, and place a thin cardboard shim behind one hinge leaf. A cereal box or a 1/16-inch piece of hardboard works. Replace the hinge pin and test.
Shimming behind the top hinge moves the bottom of the door toward the strike side (inward). Shimming behind the bottom hinge moves the top of the door inward. If the door binds at the top latch corner and the hinge side gap is wide at the bottom, shim the top hinge. If the door binds at the bottom latch corner and the hinge side gap is wide at the top, shim the bottom hinge. This method saves the paint job and keeps the door’s full width.
Sometimes the jamb itself has pulled away from the framing behind it. If you open the door and the hinge side gap is uneven or the jamb feels springy, remove one hinge screw from the jamb-side leaf and drive a 3-inch screw through the same hole into the stud behind. This pulls the jamb back tight and often clears the binding without touching the door at all. Do one screw per hinge, making sure the screw is long enough to reach the stud but not so long it penetrates the door casing on the other side.
If the frame is out of square by more than 1/4 inch, the condition won’t fix itself, and planing the door will only help temporarily. Frame racking usually means the jack studs or header have shifted. To re-square the opening, you need to loosen the casing nails on the high side, tap the jamb back into square with a straightedge and level, and re-nail using 8d finish nails through the jamb into the rough framing. This is more invasive but is the only permanent fix for a racked frame.
For DIYers, the simplest approach is to identify which side of the jamb is moved inward. Place a long level against the jamb on the hinge side and see if it’s plumb. If it’s leaning in at the top, remove the casing from that side, use a pry bar to push the jamb outward until it’s plumb, then shim behind it and nail. Replace the casing afterward. If the frame is square but the door doesn’t fit, you can also adjust the strike plate location. Remove the strike plate, enlarge the hole in the jamb slightly with a round file, and reposition the plate so the latch catches without rubbing.
Once you’ve fixed the sticking door, you can reduce the chances of it happening again. The single most effective prevention is keeping indoor relative humidity below 55 percent during humid months. A portable dehumidifier in the hallway or a whole-house dehumidifier tied to the HVAC system keeps the door’s EMC lower. Similarly, check the paint or varnish on the door edges—if the edge finish is worn, moisture penetrates faster. Touch up the edges with primer and two coats of semi-gloss interior paint before next summer.
Also inspect the weatherstripping around the door. In many homes, interior doors don’t have weatherstripping, but if yours does—especially on a door leading to an unconditioned garage or basement—make sure it isn’t trapping moisture against the door edge. Replace any worn or missing weatherstripping with low-profile felt or silicone strips that don’t compress the door too tightly.
Summer door sticking is one of those home annoyances that most people live with year after year, but understanding why it happens turns a frustrating problem into a predictable one. Next time the humidity spikes and that bedroom door starts grating, grab a piece of chalk and a block plane instead of a sledgehammer. Nine times out of ten, a careful 1/16-inch removal and a coat of paint on the raw edge will get you through the season. If the binding returns exactly the same way next year, check the frame squareness—it’s probably not the door after all.
Browse the latest reads across all four sections — published daily.
← Back to BestLifePulse