Can a cracked lath and plaster ceiling be repaired?
The short answer
Usually, yes. Fine cracks in a lath and plaster ceiling are often cosmetic and can be filled. If the plaster has come away from the laths and is sagging, it can often be re-secured with plaster washers and adhesive, or patched. Only when large areas are loose or the laths are rotten is it better to overboard or replace the ceiling.
Key points
- Hairline cracks that are not moving are usually cosmetic.
- A ceiling that bows, sounds hollow or drops dust needs a plasterer to look at it soon.
- Loose plaster can be re-fixed with plaster washers, screws and consolidating adhesive.
- Original cornices and roses can often be kept even if the flat ceiling is replaced.
- If the ceiling has a textured coating, test it for asbestos before any work.
How lath and plaster works
Most Glasgow tenements built before the 1930s have lath and plaster ceilings. Thin strips of timber, the laths, are nailed to the joists with small gaps between them. Wet lime plaster was pushed through the gaps so it curled over the back and set, forming "nibs" that hold the ceiling up. Over a century, vibration, leaks and building work can break those nibs, and that is when ceilings start to crack and sag.
Cosmetic crack or real problem?
| What you see | Likely meaning | Action |
|---|---|---|
| Fine cracks, ceiling flat and firm | Cosmetic movement | Fill and redecorate |
| Cracks along joist lines | Some nibs breaking | Get it checked; re-fix if loose |
| Bowing or sagging, sounds hollow | Plaster detached from laths | Prop or keep clear, call a plasterer soon |
| Brown staining, crumbling plaster | Water damage | Find the leak first, then repair |
A full lath and plaster ceiling is heavy. If a section is visibly dropping, keep people out of the room until it has been looked at.
The repair options
- Fill and line. For fine cracks, rake out, fill and use lining paper or a skim coat.
- Re-secure. Loose areas are pushed gently back up and fixed with plaster washers and screws into the joists. Specialists can also inject adhesive to bond the plaster back to the laths.
- Patch. Small holes can be repaired with new laths or expanded metal and plaster, matched to the existing ceiling.
- Overboard. Plasterboard is screwed over the old ceiling and skimmed. It is quicker and less messy, but it lowers the ceiling slightly and can hide the edges of cornices.
- Replace. Taking the ceiling down is very messy and should only happen when it is beyond repair. Plan for dust and protect the rest of the flat.
Your plasterer may recommend lime for repairs to match the original. See lime or gypsum plaster in a tenement for why.
Saving cornices and ceiling roses
Glasgow tenement cornices are part of what makes these flats special, and they add value. Even if the flat part of a ceiling needs replacing, a skilled plasterer can usually keep the cornice in place, or take a mould and run a matching section. If your building is listed, removing original features may need consent.
Our ranked table of Glasgow plasterers highlights firms with cornice and heritage experience.
Before any work starts
- Fix any leak from the flat above first. In a tenement, this can involve your neighbour's insurance.
- If the ceiling has a textured or Artex-style coating, have it tested. Read is it safe to remove an Artex ceiling.
- If you are rewiring, do it before the ceiling is repaired, so new cables can go in while the ceiling is open.
Questions
How much does it cost to repair a lath and plaster ceiling?
It depends on the size and the method. Small patches are often a half-day job. Overboarding and skimming a room is usually priced like a ceiling skim; see our skimming cost guide for current figures.
Can I overboard a lath and plaster ceiling myself?
It is heavy, overhead work and needs secure fixing into the joists. Most people are better hiring a plasterer, especially in a tenement with high ceilings.
Will my home insurance pay for a collapsed ceiling?
If the damage comes from an insured event, such as an escape of water from the flat above, it may. Gradual wear and tear is usually not covered. Check your policy.
Is lath and plaster better than plasterboard?
Lath and plaster has good sound insulation and suits old buildings. Plasterboard is quicker and cheaper. Repairing what you have is often the best choice in a period flat.
Sources
- Scottish Lime Centre: introduction to lime in traditional buildings (opens in a new tab)
- Checkatrade: cost of skimming a room (opens in a new tab)
This guide is general information about Glasgow and Scotland, checked on 3 November 2026. Prices and rules change, so confirm anything important with the organisation named before you act.
