Restoration Register

Heritage plaster restoration in Toronto and the GTA

A sagging plaster ceiling is almost never a reason to pull the ceiling down. In most cases the plaster keys have broken off the lath and the whole field can be re-secured from below with washers and adhesive, which is a day's work that saves an original ceiling and the cornice attached to it.

GTA heritage plaster work divides into flat work and ornament. Flat work is three-coat lime plaster on wood lath: re-keying loose fields, patching to the original thickness so the surface stays flush, and skimming with a compatible finish rather than a hard modern topcoat that will craze. Ornament is run cornices, ceiling medallions, corbels and enrichments, reproduced by running a profile in place with a zinc template or by casting from a mould taken off a surviving section. Drywall is the standard replacement answer and it is almost always the wrong one. It sits at a different thickness, kills the reveal at the cornice, and turns a repairable ceiling into a permanent loss.

What to ask before you hire

  1. Can this ceiling be re-keyed rather than replaced? Ask before anyone quotes a tear-out. The answer is yes more often than the trade admits.
  2. Will you run the cornice in place or cast it? Both are legitimate. A contractor who proposes stock polyurethane cornice from a catalogue is not doing restoration.
  3. What mix are you using over the existing plaster? A hard modern skim over soft lime plaster cracks along the boundary within a couple of seasons.
Grant funding

Interior plaster is eligible under Toronto's program where the interior is designated, and under several other GTA programs where interior features are named in the designation by-law. Check what your by-law actually protects before applying.

Contractors on this page

Part of

All heritage service pages · Grants by municipality