Most cracks and holes in plasterboard ceilings are cosmetic rather than structural and are well within DIY capability. The key is matching the repair method to the damage size, using the right product for each layer, and allowing sufficient drying time between coats. Rushing with thick coats of filler — the most common mistake — produces repairs that shrink, crack again, and fall out within months.
A well-executed patch, properly feathered and lightly sanded, should be invisible under paint. This guide covers everything from hairline cracks to access holes of up to 200 mm across.
Tools and Materials
| Item | Approx cost (2026) | Notes |
|---|---|---|
| Jointing compound (e.g. Gyproc EasiFill 60 or similar) | £6–£12 per 2 kg tub | Use for filling and first coats |
| Fine surface filler (ready-mixed) | £5–£10 per 600 ml tub | For final thin skim coat |
| Paper jointing tape (50 mm wide) | £3–£6 | For cracks wider than 2 mm |
| Self-adhesive fibreglass mesh tape | £4–£8 | For medium holes — easier to position overhead |
| Plasterboard backing plates / access hole repair kit | £8–£18 | For holes 50–200 mm diameter |
| 150 mm and 250 mm plastering knives / drywall knives | £12–£30 | Wide knife for feathering |
| Fine-grit sanding sponge (120–180 grit) | £2–£5 | Wet-sand between coats |
| Dust sheet and step ladder | Already owned / hire | — |
| Mist coat primer or contract matt | £8–£15/2.5L | Essential before top coat paint |
Diagnosing the Damage
Before grabbing the filler, it is worth a 60-second inspection:
- Hairline crack along a joint — almost always the taped joint between two plasterboard sheets opening up as the building moves seasonally. Not structural.
- Crack radiating from a corner — can indicate differential movement, but in ceilings this is typically thermal expansion of the boarding. If the crack has grown over several months, investigate before filling.
- Circular or irregular hole — access for a light fitting, pipe, cable, or physical impact damage.
- Sagging area or multiple parallel cracks across the ceiling — potential screw-pull through or damaged noggins. Do not fill; investigate whether the board is secure before proceeding.
- Brown staining at crack edges — historic or active water ingress. Fix the leak before any repair work. Stained plaster must be sealed with a stain-blocking primer (such as Zinsser BIN) before painting or the stain will bleed through.
Repairing Hairline Cracks
For cracks narrower than 2 mm with no movement history:
- Widen the crack slightly with a scraper or the corner of a filling knife — a slightly wider, clean V-profile accepts filler better than a tight hairline.
- Brush out dust and lightly dampen the crack with a damp brush.
- Press jointing compound into the crack with a 150 mm knife, drawing it slightly proud.
- Allow to dry fully (at least 2 hours at 18°C; longer in cool or humid rooms — ceilings in winter can take 4–6 hours per coat).
- Lightly sand flush and apply a second thin coat if the first has shrunk visibly below the surface.
- Finish with a thin final skim of ready-mixed fine filler, feathering 50–75 mm either side of the joint to blend into the ceiling.
- Sand with a damp sponge when just dry — ceiling dust falls in your face; a damp sponge reduces airborne particles considerably.
Repairing Cracks Along Plasterboard Joints (With Tape)
If a joint crack keeps reopening, the original tape has failed and needs re-bedding:
- Rake out the old tape with a scraper.
- Spread a thin bed of jointing compound along the joint with a 150 mm knife.
- Press a strip of 50 mm paper tape into the wet compound and draw the knife along it firmly to embed it, removing excess compound.
- Allow to dry, then apply a wider first coat (200 mm knife) over the tape, feathering the edges.
- Second coat with a 250 mm knife when the first is dry — this wide feathering is what makes the joint invisible.
- Light sand, prime, paint.
Repairing Small to Medium Holes (up to 100 mm)
For holes left by old light fittings, cable entry points, or minor damage:
- Clean up the hole edge — irregular tears are harder to fill than a neat circle or square. Use a padsaw or drywall knife to cut to a clean shape.
- Apply self-adhesive fibreglass mesh tape across the hole (it will bridge a gap of up to about 60 mm without backing).
- Apply a first coat of jointing compound across the mesh, pushing it through the mesh to anchor it.
- Allow to dry; the mesh will telegraph through if you apply the second coat too soon.
- Build up with two to three thin coats, feathering wider each time.
- Finish with fine filler, sand, prime, paint.
For holes 60–150 mm, a proprietary backing plate kit gives a far more stable base. Most kits use a rigid board with a toggle or toggle-bar mechanism that grips behind the existing plasterboard. Follow the kit instructions, then tape and fill over the patch as above.
Repairing Larger Holes (100–200 mm+)
For holes above about 150 mm, the most reliable repair involves a timber-backed patch:
- Cut the damaged area back to a rectangle with a padsaw, extending the cut to centre over the nearest joist or noggin on each side if possible.
- Fix short offcuts of 50×25 mm timber behind the existing board using screws driven at an angle through the surrounding board — these act as a ledger for the patch.
- Cut a piece of new 12.5 mm plasterboard to fit the hole and screw it to the timber ledgers.
- Tape all four joints with paper tape bedded in jointing compound.
- Build up coats as described above.
This approach is more involved but produces a repair with structural backing. For holes larger than about 300 mm, consider whether it is more economic to replace the entire board.
Cost to Hire a Plasterer
| Task | Typical cost (2026) |
|---|---|
| Small crack filling (1–3 cracks, one room) | £80–£150 |
| Multiple patches, one room | £150–£300 |
| Full re-skim of one ceiling (e.g. 15 m²) | £250–£500 |
| Full re-board and skim (15 m²) | £400–£800 |
Plasterers typically charge £180–£280/day (2026 UK), so small patch jobs are often quoted as a half-day minimum. Grouping several rooms’ repairs into one visit reduces the per-job cost significantly.
When to Re-Skim Rather Than Patch
If a ceiling has more than four or five discrete cracks, widespread small holes, or a surface that is visibly uneven, patching each defect individually quickly costs as much as or more than a full re-skim. A plasterer can skim a 15 m² ceiling (one coat over existing plaster) in three to four hours; this gives a flat, uniform surface and is often the more economic and better-looking outcome.
