Why is my front door hard to lock?

A front door that is hard to lock is usually a door problem, not a lock problem. The deadbolt bolt has to slide straight into a hole in the frame, through a metal strike plate. If the door has moved even a little, the bolt rubs on the edge of the strike and you end up pushing, pulling or lifting the door to turn the key. The fix is usually a screwdriver and some patience, not a new lock.

First, find out whether it is the lock or the door

Open the door and work the deadbolt with the key and with the thumb turn, several times. Then close the door and do it again.

• Smooth with the door open, stiff with it closed: the lock is fine. The bolt is rubbing on the strike, and the rest of this page is for you.
• Stiff even with the door open: the problem is inside the lock or the cylinder. Skip to "When it is the lock itself" below.

The common causes

The door has dropped out of line. Schlage lists the usual reasons a door stops lining up with its lock: "your house has settled or shifted over time, the door frame is old or warped, or the door is sagging on its hinges."^[1] The way you fight the door is a clue. In Schlage's words, "if you have to lift your door to lock it, that could be a sign that your bolt or latch is hitting the bottom of the strike rather than extending fully into it."^[1]

Loose hinges. The top hinge carries most of the door's weight, and when its screws loosen, the latch side of the door drops. Schlage notes that worn or loose hinges can let the door sag, and that replacing the hinges or adding shims under them are the two ways to correct it.^[1] Therma-Tru's installation manual shows why the top hinge matters: it calls for #10 x 2-1/2 inch screws in place of the two top-hinge screws closest to the weather strip, through the hinge and into the stud, to anchor the door frame and prevent sagging.^[2] Short screws that only grip the thin jamb work loose over the years.

Weather. If the door locks easily part of the year and fights you the rest, Schlage says it may be a sign that "changes in temperature or moisture are causing your door to warp, even just temporarily."^[1] Wood moves with humidity: Simpson Door notes that its wood doors "may shrink or swell slightly as it “breathes” with climate changes",^[4] and its fitting instructions allow about 3/16 inch of clearance for swelling when a door is hung in fully dry conditions.^[4] Schlage recommends making adjustments at the time of year when the door is not fitting, not when it is.^[1]

Weatherstripping. New, thicker weatherstripping pushes the door away from the stop, and the bolt no longer meets the strike squarely. Schlage warns against weather stripping that is so thick it obstructs the bolt or keeps it from entering the bolt pocket,^[1] and suggests a thinner strip or moving the strike. Therma-Tru's installers do the reverse on a new door, moving the strike plate in or out to get proper weatherstrip contact and door operation.^[2]

A shallow or misplaced bolt hole. The bolt needs room to extend all the way. If the hole behind the strike is shallow, the bolt bottoms out and the key will not turn fully. Schlage's fix is chiselling the bolt hole until it is 1 inch deep and lets the bolt extend fully without dragging.^[1]

Finding exactly where it rubs

Schlage passes on a simple trick: "Put some chalk – lipstick also works – on the bolt before locking and unlocking it."^[1] Close the door, lock and unlock it, then open it and look at the strike. The smear shows where the bolt is rubbing, and the bolt is probably rubbing on just one or two sides of the strike.^[1] A smear along the bottom edge points to a sagging door. A smear on the outer edge points to a door that sits too far out, often because of weatherstripping.

If the rub is small, chiselling a little wood out of the bolt hole at that spot, or filing the strike opening slightly, is often enough. If it is larger, the strike needs to move, which means filling the old screw holes and re-drilling. When you replaced the lock, did you keep the old strike? Schlage says the supplied strike is the correct size and shape for the bolt to extend and retract without dragging,^[1] so fit the one that came with your lock. For a stubborn case, Schlage offers an alternate strike and security plate with more clearance from its customer support.^[1]

When it is the lock itself

If the bolt is stiff with the door open, the cylinder or bolt mechanism is dirty, dry or worn. JELD-WEN's care guide recommends cleaning door hardware and tightening loose screws any time a door is not opening or closing properly, or at least biannually,^[3] and calls for spraying the lock's keyway with graphite lubricant and oiling hinges with a light oil annually or when they are noisy.^[3] Check your lock's own manual too; makers differ on lubricants. A key that is bent or badly worn can also make a good lock feel stiff, so try a spare.

Stop and call a pro if

• The jamb is cracked or split around the strike, the frame has pulled away from the wall, or the wood near the bottom of the frame is soft. That is a frame repair, often after a forced entry or years of water.
• The door rubs along its whole edge, will not close at all, or the gaps around it are wildly uneven. It may need rehanging or a new frame.
• The cylinder spins, a key breaks off, or the lock was damaged. Virginia's private security services law defines locksmith services to include adjusting, installing or rekeying locks and deadbolts,^[5] and locksmith is one of the registration categories for private security services.^[5]
• A motorised smart lock struggles after you have fixed the alignment. Contact its maker before taking it apart.

Related on Loclis

If the door is drafty as well as stiff, see how to weatherstrip a drafty door and how often to check weatherstripping and caulk. If the frame is past saving, see what a new front door costs installed in Virginia. Browse door repair businesses, entry door businesses and more exterior answers. To have it fixed, describe your door problem once and local businesses will quote it.