Plaster Repair near you

A plaster wall is built in place. Narrow wood strips, the lath, were nailed across the studs with small gaps between them, and plaster was pressed on in several coats. The first coat squeezed through the gaps and curled behind the lath, forming the keys that hold the whole surface to the wall. Drywall, by contrast, arrives as factory-made panels fastened to the framing, with taped and filled joints.

The difference shapes the repair. Plaster is thicker and harder than drywall, often gently wavy, and usually finished with a hard, smooth top coat. A patch made with soft drywall compound alone tends to stay visible, and fasteners that work well in drywall can crack plaster if they are driven carelessly.

Not every crack is urgent, but the pattern tells a plasterer what is going on. Framing that moves, heating seasons that dry the house out and an old building that has settled over decades all show up in plaster first. The key question is whether the plaster is still firmly attached to the lath behind it.

Every repair starts with the base. A plasterer checks by hand and by sound which areas are solid and which have come loose, removes crumbling material and cuts back to firm edges. Areas damaged by water are repaired only once the leak has been fixed and the wall has dried out.

Loose plaster is reattached rather than buried under filler. Plaster washers, thin perforated discs, are screwed through the plaster into the lath or the framing to draw the surface back and hold it, sometimes after an adhesive has been injected behind it. The washers then disappear under the finishing coats.

Most plaster can be repaired, and repair is usually far less disruptive than tearing out. Replacement starts to make sense when large areas have lost their keys, when the lath is rotten or badly water-damaged, when the wall is being opened anyway for new wiring, plumbing or insulation, or when layers of earlier repairs no longer hold together.

There is also a middle route: new drywall laid over sound plaster, or a full skim coat over a wall covered in small repairs. Covering keeps demolition to a minimum but makes the wall thicker, so door and window casings, electrical boxes and baseboards may need adjusting.

Tearing out is the messiest option: it creates heavy debris and fine dust, disturbs every old layer of paint and coating, and in an older home should only begin after testing.

In an older home, plaster is part of the character: rounded corners, cornices, ceiling medallions and walls that follow the soft irregularities of the framing. Repairing it keeps original material, avoids the dust and waste of demolition and preserves details that drywall can't reproduce. Ornamental work is a specialty, so ask whether the plasterer can run a cornice in place or cast a missing piece to match the existing profile.

In Quebec, the government says the owner of a classified heritage building must obtain authorization before altering, restoring, repairing or modifying it. If your home has a heritage status, ask the Quebec culture ministry or your municipality what applies to interior work before hiring anyone. The masonry page describes the conservation standards and heritage rules that apply to older buildings more broadly.

The layers on a plaster wall can be of very different ages. The Quebec government says asbestos products were used in construction in Quebec mainly between 1930 and 1990, and its list of materials that may contain asbestos includes wall and ceiling coatings, patching compound and drywall repairs. A wall with old patches or a textured finish may need testing even when the plaster underneath is older still, and when in doubt the Quebec government advises handling a material as if it contained asbestos.

Paint is the second concern. Health Canada says a home built before 1960 probably contains lead-based paint and warns against sanding it or stripping it with heat. Have painted plaster tested before anyone sands or scrapes it, and if asbestos is found, the affected work goes to a qualified asbestos removal contractor.

Plaster dust is fine and heavy, and it settles in every corner of a house; sanding compound only adds to it. Dust control is part of the job rather than an extra, and it matters even more when old paint or coatings are being disturbed.