How plaster walls are built
Before drywall became standard, walls were built from thin strips of wood, called lath, nailed across the studs with small gaps between them. Plaster was pushed through the gaps, where it curled behind the lath and hardened into "keys" that hold the wall on, then built up in two or three coats. Mid-century homes often have gypsum lath or veneer plaster instead. Knowing which you have matters for the repair.
Common problems
- Hairline cracks from normal settling and seasonal movement.
- Wide or recurring cracks, often over doors and windows, from movement in the structure.
- Loose or bulging plaster that sounds hollow when tapped: the keys have broken and the plaster is coming away from the lath.
- Holes from impact, old fixtures or plumbing and electrical work.
- Water damage, which softens plaster and can make paint bubble or flake.
Before you start: lead and asbestos
Health Canada advises that a home built before 1960 probably contains lead-based paint, and that homes built up to 1990 may have it on exterior surfaces. Painted plaster in an older home should be treated as lead-painted until tested, which means no dry sanding and careful dust control. Some plaster, textured finishes and joint compounds also contain asbestos. In BC, WorkSafeBC requires possible asbestos in homes built before 1990 to be identified before work disturbs it, so a sample test comes first.
How each repair is done
Loose plaster. Rather than tearing it out, the plaster is re-attached to the lath with screws and wide plastic plaster washers, often with an adhesive injected behind it, then the washers are skimmed over.
Cracks. The crack is opened slightly and cleaned, loose material removed, then bridged with fibreglass mesh tape and setting-type compound or plaster in thin coats. Setting-type compound bonds well to plaster; premixed drywall compound is more likely to crack again.
Holes. Small holes are filled in layers with setting compound. Larger holes get new lath or a piece of drywall shimmed to the depth of the surrounding plaster, then finished flush.
Walls with many cracks. A skim coat over the entire wall, or laminating with thin ¼-inch drywall, can be cheaper than repairing dozens of separate cracks.
Repair or replace with drywall?
Repair keeps the original walls, their sound-deadening mass and their trim details, and is almost always cheaper for localized damage. Replacing plaster with drywall means demolition, dust, disposal, and often new trim, because drywall is thinner than the plaster it replaces. For wall repairs in drywall homes, see drywall repair cost.
What plaster repair costs
| Job | Typical cost |
|---|---|
| Small patch or crack job, Metro Vancouver Drywall repair rates; plaster tends to cost more | $150–$600 |
| Handyman labour, Vancouver | $70–$120 / hr |
| Larger areas or many cracks Skim coat or overlay may be cheaper than patching | Quoted after photos |
For drywall walls, see drywall repair cost.
Common questions
Can I use drywall compound on plaster walls?
Yes. Setting-type compound bonds well to plaster and is the usual choice for crack and hole repair. A bonding agent helps on very smooth or painted plaster.
Why do plaster cracks keep coming back?
Usually because they were filled without being bridged with tape, or because the plaster around them is loose. Re-attaching loose plaster and taping the crack stops most recurring cracks.
Can I hang pictures on plaster walls?
Yes. Drill a pilot hole first rather than hammering a nail, which can crack the plaster, and use a screw into the lath or a stud for anything heavy.
Related guides
Metro Vancouver drywall repair and labour rates from published 2026 local pricing guides (HomeStars, local contractors), in CAD. Lead guidance from Health Canada; asbestos requirements from WorkSafeBC. We update these figures as we complete jobs.