Crack appeared in your ceiling in Woolwich? How to tell a harmless hairline crack from one that needs attention, and how ceiling cracks are repaired properly.
Most ceiling cracks are cosmetic. Plaster and plasterboard move slightly as a house warms up and cools down, as timber joists dry out, and as people walk about upstairs, and that movement shows up as fine lines, usually along the joints between plasterboard sheets or around the edges of the room. They look worse than they are.
The type of ceiling matters. In the Victorian terraces around Plumstead and Woolwich Common, many ceilings are still the original lath and plaster, and cracks there can be a sign the plaster is losing its grip on the timber laths above it. In newer homes, the Royal Arsenal riverside flats and the estates around Abbey Wood and Thamesmead, cracks usually follow the plasterboard joints, where the tape underneath was not bedded in well.
What deserves a closer look is a crack that keeps growing, one that has a step in it where one side has dropped lower than the other, or a crack that comes with a bulge, a stain or a sag. Those can mean the plaster is coming away, or that water is getting in from above. A straight hairline crack along a board joint is almost always just a repair job.
Fine hairline cracks are almost always cosmetic. A crack with a step, a sag, a bulge or a stain is different and should be checked, because the plaster may be coming away.
Filler alone does not stop movement at a plasterboard joint. A proper repair cuts the joint out, re-tapes it and skims over it so it holds.
Usually not. Most cracks can be repaired on their own. If an old lath and plaster ceiling is coming away in several places, overboarding and skimming can be the better fix.
Rarely, on a ceiling. If cracks are wide, growing quickly, or doors upstairs have started sticking, get a surveyor to look before any plastering is done.
A straight crack along a line is usually a plasterboard joint. Random, spidery cracks are more common on old lath and plaster ceilings.
If the ceiling moves, feels soft or sounds hollow when you press lightly with a flat hand, the plaster may be coming away. Do not push hard.
A brown stain, a bulge or a sag next to a crack usually points to water from a bathroom, tank or roof above. That needs sorting first.
Mark the ends of the crack lightly with a pencil and the date. If it grows past the marks over a few weeks, it needs looking at.
A photo of the crack and one of the whole ceiling helps us tell you what is likely going on before we visit.
Send a photo or a quick video of the room on WhatsApp, or get a free fixed quote, no obligation, and we’ll tell you straight what it needs.
