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WALLS & CEILINGS

Ceiling Crack

Ceiling cracks may be harmless surface defects, but widening cracks, sagging, staining or loose plaster need closer investigation.

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Check for hidden cables, pipes, loose plaster and moisture before drilling, cutting or removing material

Wear eye and dust protection. Stop if the surface is sagging, heavily damp, contains suspect asbestos materials or shows significant structural movement.

MOST LIKELY CAUSES

Start with these

Plasterboard joint movement Cracks often follow board seams.
Drying shrinkage Fine cracks can develop in new plaster.
Water damage Leaks weaken plaster and jointing materials.
Structural movement Wider or stepped cracks may indicate movement.
◫ Symptom variations Match the exact damage, movement or finish defect. ⌄
  • Straight crack along board joint
  • Hairline ceiling crack
  • Brown staining
  • Sagging nearby
  • Crack widening over time
✓ Quick checks Simple checks before cutting or filling. ⌄
  1. Identify the wall or ceiling material.
  2. Check for damp, leaks or movement.
  3. Look for hidden service zones.
  4. Remove only loose material.
  5. Choose filler and fixings for the substrate.
1 Step 1 — Check for danger signs Check for hidden cables, pipes, loose materials and moisture before cutting or drilling. ⌄

Look for sagging, staining, dampness or loose material.

2 Step 2 — Confirm the ceiling is dry and stable Check for hidden cables, pipes, loose materials and moisture before cutting or drilling. ⌄

Repair the leak or movement cause first.

3 Step 3 — Reinforce and finish Check for hidden cables, pipes, loose materials and moisture before cutting or drilling. ⌄

Tape recurring joints, apply compound, sand and repaint.

⌁ Common causes explained Why wall and ceiling defects develop. ⌄

Ceiling cracks may be harmless surface defects, but widening cracks, sagging, staining or loose plaster need closer investigation.

⌘ Advanced diagnostics Further checks for recurring or serious defects. ⌄
  • Inspect the space above.
  • Check board fixings and joists.
  • Test for moisture.
  • Assess artex or older coatings before disturbance.
  • Seek structural advice for significant movement.
▣ Parts and materials needed Common materials linked to this repair. ⌄
  • Joint tape
  • Jointing compound
  • Drywall screws
  • Stain-blocking primer
  • Ceiling paint
! When to call a professional Conditions that should end basic DIY work. ⌄
  • Cracks are widening or structural.
  • The ceiling is sagging or unstable.
  • There is significant damp or water damage.
  • Large areas of plaster are loose.
  • Hidden services or suspect asbestos may be present.
? Frequently asked questions Common wall and ceiling repair questions. ⌄

Can I fill over a moving crack?

No. The cause of movement should be understood first or the repair is likely to fail.

Do I need primer over filler?

Usually yes. Porous filler can flash through paint unless it is sealed or primed.