Plastering in Ontario

A skim coat is touch-dry in a day but needs roughly a week to fully dry before painting; full re-plaster can take several weeks depending on thickness, ventilation and season. Paint too early and you trap moisture, causing peeling. Use a mist coat (diluted emulsion) first.

Yes, if the substrate is sound — plasterers key the surface and use bonding agents. But blown (hollow-sounding), crumbling, or damp-stained plaster must come off first. A good plasterer taps the walls during the quote to check; be wary of anyone who doesn't.

Fine crazing usually means the plaster dried too fast (heat, draughts) and is cosmetic — fill and paint. Straight-line cracks along boards or above doors indicate movement at joints. Wide or recurring cracks are worth a builder's inspection before redecorating.

It is one of the messiest trades — expect splatter, dust and high humidity. Empty the room if possible, or centre furniture under sheeting. Floors should be fully covered. Ask whether the quote includes protecting surfaces and cleaning up.

Rendering is exterior plastering with cement- or silicone-based mixes to protect and finish outside walls; plastering refers to interior walls with gypsum or cement finishes. Many plasterers do both, but exterior render is priced and scheduled differently (weather-dependent).

No — plaster over damp fails within months. The moisture source (rising damp, leaking gutter, condensation) must be fixed first, then damaged plaster cut back and replaced, sometimes with a salt-resistant renovation plaster. Any plasterer who skips the cause is selling you a repeat job.

It can — asbestos was added to plaster, stucco and drywall compound into the 1980s. A lab test on a small sample costs little and is required before contractors legally sand or demolish suspect material in most provinces.