The Trades AlmanacA homeowner's reference for every system in the house

How it works: Carpentry

How a door hangs, and why it sticks

Hinges, jambs, the strike plate, and the gap that has to stay open all year

An old wooden workbench with hand tools, a wooden mallet and a brass level in low afternoon light
An old wooden workbench with hand tools, a wooden mallet and a brass level in low afternoon light

A door is a wooden slab hung from two or three hinges inside a wooden frame, and it works only while there is a sliver of air all the way around it. When that sliver closes, the door sticks. The two usual reasons are that the hinges have let go a little, or that the wood has grown. This page covers the parts, the gaps, and the order of fixes, which starts with a screwdriver and ends, only if it must, with a saw.

The parts

A door in its frame: head jamb, hinge jamb with three hinges, strike jamb with strike plate, stop, casing, and the gaps around the slab 1/16 in. gap, hinge side 1/8 in., strike side Head jamb Hinge jamb Strike plateon the strike jamb Casing (trim) Hinges: the top one works loose first Stop: the slab closes against it Dashed line: the stop. The slab, the panels and the frame all swell in humid months.
A door in its frame. The slab hangs from hinges on the hinge jamb and closes against the stop; the latch enters the strike plate on the strike jamb. A 1/16-inch gap at the hinge side and 1/8 inch at the head and strike side keep it swinging through the seasons.

The frame. A door frame supports the door and consists of the head across the top, the jambs up each side, and, on an exterior door, the sill at the bottom. The side jamb the hinges are mounted in is the hinge jamb; the other is the strike jamb.

The slab. JELD-WEN’s term for the operating part of the door assembly that swings open and closed inside the frame.

The stop. A strip fixed to the inside of the jamb that the slab closes against. It is what keeps the door from swinging through the opening.

Hinges. The metal component that attaches the slab to the jamb and allows it to swing. The screws in the jamb-side leaf are the ones that work loose.

Latch and strike plate. The latch extends from the side of the door into the frame and retracts when the handle is turned. The strike plate is the metal plate on the strike jamb where the latch or bolt meets the frame.

Casing and reveal. The casing is the trim around the opening that hides the gap between the frame and the wall. It is set back slightly from the jamb’s edge, leaving a narrow strip of jamb showing, the reveal; one trim guide marks it 3/16 inch from the edge.

The gaps

JELD-WEN’s installation instructions specify about a 1/16-inch gap between the slab and the hinge jamb, and 1/8 inch between the slab and the head and strike jamb. Those small, even gaps are the whole point of hanging a door carefully. They are the allowance for the seasons.

Why it sticks

The Home Depot’s repair guide names both causes: hinges can become loose, or seasonal humidity can cause warping, because wood doors and frames shift and change depending on the humidity level in your home. The humidity half is the wood story told in how wood moves with the seasons: when the air is humid, wood adsorbs moisture and swells; when it is dry, wood shrinks. A door that swells 1/16 inch in a frame that swells 1/16 inch has used up its 1/8-inch gap.

The hinge half is mechanical. A door is a lever hanging from screws in soft jamb wood. Over years the top hinge screws loosen, the slab drops a hair at the latch side, and the top corner rubs the head jamb while the bottom corner rubs the strike jamb. That pattern, rubbing at the top latch corner, is the signature of a loose top hinge, and it is the one to check first because it costs nothing.

The fixes, in order

  1. Tighten the hinge screws. The Home Depot’s guide: tighten one at a time until you have solved the problem, checking the door as you go. Most sticking doors stop here.

  2. Replace stripped screws with long ones. If a screw spins without biting, replace it with a longer 3-inch wood screw that reaches through the jamb into the wall framing behind it. JELD-WEN’s own instructions call for a 2-1/2-inch screw through each of the top two hinges into the framing on heavier solid-core and stile-and-rail doors; on a hollow door it is still the strongest fix for a drooping hinge.

  3. Fix the latch. If the door swings freely but will not stay closed, the latch is missing the strike. Tighten the strike plate screws one at a time, checking the door after each; if the hinges were the problem, step 1 usually brings the latch back into line.

  4. Find the rub, then trim. The Home Depot’s guide says the key to fixing a sticking door is to determine the cause. If tightening did not cure it and the rub is seasonal swelling, mark the spot where it rubs while the door hangs, take the door off its hinges, and remove material along the marked edge with a sander or a saw (a hand plane does the same work on a solid wood door). JELD-WEN’s limit for its molded and flush doors is a maximum of 1/4 inch trimmed from each side. Take off the least that frees it; a door trimmed in August will be a loose door in February.

  5. Seal the cut edge. JELD-WEN: the slab should be finished, painted or stained, on all six sides with an equal number of coats after all trimming and boring is done. A raw edge soaks up moisture faster than the finished faces, swells, and brings the problem back.

Hanging a new door

The same parts in reverse: the frame goes into the rough opening plumb and square, held off the framing with shims behind each hinge and the strike, with the gaps above set before the casing goes on. A level on the hinge jamb and a tape across the diagonals of the frame are the two checks. A frame that is out of plumb gives a door that swings open or closed on its own.

When to call a carpenter

A door that sticks at the top on one side and the bottom on the other, with the gaps visibly uneven, may be in a frame that has racked as the house settled, and the fix is re-hanging the frame, not shaving the door. An exterior door that has swollen enough to leak or to defeat the lock, or any door in a wall that is cracking at the corners of the opening, is worth a carpenter’s or a contractor’s eye, because the door may be reporting a problem in the wall.

References

  1. Parts of a Door: Front Door Anatomy 101. Pella. https://www.pella.com/ideas/doors/entry-doors/parts-of-a-door/
  2. Installation Instructions for Interior Door Slabs (JII110). JELD-WEN. https://images.thdstatic.com/catalog/pdfImages/c4/c4e413f0-2507-4cf8-aca0-e604fc01a6d9.pdf
  3. Interior Trim Work Basics. Family Handyman. https://www.familyhandyman.com/project/interior-trim-work-basics/
  4. How to Fix an Interior Door. The Home Depot. https://www.homedepot.com/c/ah/how-to-fix-an-interior-door/9ba683603be9fa5395fab9016815bceb
  5. The Shrinking and Swelling of Wood and Its Effect on Furniture (FNR-163). Purdue University Forestry and Natural Resources. https://www.extension.purdue.edu/extmedia/FNR/FNR-163.pdf

Every fact and number on this page comes from one of the sources above, read during the writing of this page. Codes and standards vary by jurisdiction and edition; your local code and your equipment's manual control.