Question: A visible crack or gap has opened at the joint between the wall and the plaster cornice. Will regular polyfilla keep it closed?
Answer: Regular polyfilla usually lasts three to six months at this joint. The wall and the ceiling expand at different rates in Malaysian heat and humidity, so a rigid fill pops. The lasting repair is to rake out loose material, fill with flexible acrylic, reinforce larger gaps with mesh tape, then skim, prime and repaint to match. Replace the cornice only if it has fully detached or is heavily water-damaged.
This is the wall–ceiling cornice joint, not cracked plaster ceiling board joints in the field of the ceiling, and not hairline cracks on painted walls.
Why the Cornice Joint Opens
- Thermal expansion of the ceiling versus the wall.
- Cornice adhesive drying out over time.
- Water damage weakening the plaster bond — check for stains at the same time.
- Building settlement in the first five years.
When It Is More Than Cosmetic
| Sign | Action |
|---|---|
| Hairline along the mitre or wall line | Flexible fill + paint |
| Gap wider than 3 mm | Mesh + skim, not filler alone |
| Cornice starting to detach | Secure or replace the run |
| Water stains at the same joint | Find the leak first |
A stain at the cornice is a leak clue — see ceiling leak after rain before decorating.
What Repair Involves
- Rake out loose compound and vacuum the joint.
- Fill with flexible acrylic filler.
- Embed mesh tape for larger gaps.
- Skim, prime and repaint to match the existing cornice and wall.
Typical bedroom cornice repair (fill + skim + repaint) is RM 200 to RM 380. Living rooms or larger runs are RM 450 to RM 900. Published problem range is RM 200 to RM 900+ depending on room count.
KL Servis Rumah publishes cornice and L-box concealed light trough on quote, water-damaged ceiling repair from RM 220, and ceiling repair and re-skim from RM 8 per sq ft. Ceiling repair carries the 90-Day Structural Sagging & Crack-Free Warranty.
Compare ceiling types in gypsum vs plaster ceiling.
Related Problems
- Cracked ceiling joints — board joints in the ceiling field.
- Sagging plaster ceiling — the board is dropping, not just the cornice line.
- Hairline cracks on walls — the wall field, not the cornice.
Frequently Asked Questions
Can I fix cornice cracks with regular polyfilla?
It lasts 3–6 months. Flexible acrylic filler plus mesh lasts years even with thermal movement.
Do I need to replace the entire cornice?
Only if it is fully detached or heavily water-damaged. Most cracks are surface repair only.
How much per room?
Typical bedroom RM 200 to RM 380. Living room or larger area RM 450 to RM 900.
Close the Joint So It Stays Closed
If the same cornice line opens after every repaint, the filler is too rigid. KL Servis Rumah provides ceiling repairs across Kuala Lumpur and Selangor.
Send a photo of the gap and say whether you also see water stains — WhatsApp our ceiling team.