8 ways to fix a door that won't close

Doors are an essential part of every home, but sometimes your doors just won't close. One of these eight practical tips may help you find some solutions to common door problems.

If a door refuses to shut or keeps swinging open, first diagnose and fix the underlying problem, then spray the hinges regularly with an oil-based lubricant.

To check if a door's latch and strike are out of alignment, smear lipstick on the edge of the door's latch and stick masking tape to the strike plate.

• Open and close the door. If there is a gap between the smudge and the hole, measure it.
• If there is no gap, check if the latch is going far enough into the strike hole, or if it's sticking due to paint build-up.

Lubricate your latches every six months to avoid latch problems. Use an multi-purpose, oil-based lubricant.

• Fix the plastic straw that comes with your multi-purpose lubricant in the nozzle to focus spray around the bolt, then wipe off any excess with a rag.
• Graphite powder is another effective latch lubricant. However, never mix lubricants – it's a sure way to gunk up a latch assembly.

If there's a build-up of old paint around a latch, use a utility knife to break the seal around the latch and scrape paint off its surface. If the latch in an older mortice-type lock case continues to stick, then you'll need to repair the lock case.

If a door's latch is too high or low for the strike, make sure all the hinge screws are tight.

• If that doesn't work, remove one of the screws on the jamb side of the hinge and drive in a 7.5 centimetre  screw. This will grab the wall framing and draw in the whole door jamb slightly.
• To raise the latch, install this screw in the top hinge.
• To lower the latch, install it in the bottom hinge.

If the latch is missing the strike hole by 0.3 centimetres (1/8 of an inch) or less, enlarge the hole.

• Use a simple metal grinding bit suitable for use in a drill, or a half-round file matched to the curve of the hole.

If the latch on an old interior door no longer extends far enough out of the latch hole to keep the door from swinging open, install a second strike plate over the first.

• If you can't find a matching strike plate, pack out the old one with cardboard or laminate.

If the latch isn't going into the strike far enough or is missing the hole by more than 0.3 centimetres (1/8 inch), move the strike plate up or down, in or out as required.

• First, use a sharp chisel to enlarge the rabbet.
• Then hold the strike plate in place and drill new holes for the screws.
• Install the strike plate and fill the gap in the remaining rabbet with wood filler.

Keep these eight practical tips in mind, and you'll be able to solve some common problems with doors that won't close.