Easy fix for a jammed garage door

When an up-and-over, or canopy, garage door doesn't open, it may have dropped out of its vertical guide track. This can happen when you open or close the door from one side, rather than in the middle, or try to open or close it too quickly.

• To put it back, lift the side that's in the track as high as possible while keeping the loose side low. With a bit of pushing, you should be able to pop the loose roller back into the track.
• Check that the rollers aren't worn or missing. Replacements are available from garage door specialists.
• Dirty tracks may cause the door to stick and make you pull it unevenly. Clean out the tracks with a rag soaked in denatured alcohol — take care as the metal edges can be sharp.

Hinged garage doors are heavy and can sag over time. If the lower edge of the door drags on the ground, it will sustain damage and make a grating noise whenever it is opened and closed.

• Open the door, and push a wooden wedge beneath the edge farthest from the hinge so that the door is level. Loosen — don't remove — the screws or bolts holding the hinges to the frame and door. Tighten the screws holding the hinges in place. If the screws are loose, replace them with longer screws with the same head size, or pack out the screw holes with matchsticks.
• For a long-term solution, buy and fit a caster to each door. These large wheels, available from DIY stores, fix to the bottom of the door and support it against the ground. Installing the casters will involve taking the doors off. Casters are usually spring-loaded to cope with uneven surfaces.

• Many canopy, or up-and-over, garage doors have a large spring to provide the lifting power. The spring stores a huge amount of energy and can cause serious injury if released or removed incorrectly.
• Don't attempt a garage-door repair unless you know exactly what you are doing. If in any doubt, call in a professional.