Plaster Crack Repair, SydneyWall cracks, ceiling cracks, cornice-junction cracks — diagnosed and fixed for good.

Most plaster crack repairs in Sydney cost $290 to $800 depending on crack length, location, and finish standard. A single hairline crack under a metre in an accessible room sits at the lower end. Multiple settlement cracks, cornice-junction cracks, or ceiling-crack repairs at height sit at the upper end. Every quote is fixed-price and written — no hourly rates.

Most Sydney plaster cracks are cosmetic — house settlement, wet/dry seasonal movement, or minor impact. Hairline cracks under 1mm are almost always cosmetic. Cracks wider than 2mm, cracks that grow month-on-month, cracks running diagonally across load-bearing walls, or cracks accompanied by sagging or doors that suddenly stick — those need a plasterer to inspect, and possibly a structural engineer if we spot underlying movement.

Sydney plaster walls crack for five main reasons. (1) House settlement — soil expansion and contraction between wet and dry seasons, especially on the Northern Beaches sandstone-and-clay sites. (2) Age — plaster over 30 years old loses flexibility and cracks under normal thermal movement. (3) Impact — TV brackets, furniture knocks, DIY drilling. (4) Cornice failure — old cornices detach from the wall-ceiling junction and pull adjacent plaster with them. (5) Vibration — bus routes, nearby construction, upstairs renovation. Correct diagnosis matters for correct repair.

The right method depends on crack width. Under 1mm: sand back, apply flexible filler, feather with joint compound, skim, sand, paint-ready. 1-3mm: cut back to sound plaster, re-tape with fibreglass mesh, apply topping compound over the tape, feather 300mm each side, sand, skim, paint-ready. Over 3mm or sagging: cut out the damaged section entirely, replace with new plasterboard, re-tape at joins, skim, paint-ready. All three methods carry the 2-year written guarantee.

Not if we diagnose and repair correctly. Cracks re-emerge when the underlying cause is ignored — the classic mistake is skim-filling a settlement crack without cutting back, re-taping, and using a flexible compound. We inspect first, identify the cause (settlement / age / impact / cornice failure), and repair to the standard the cause requires. Cosmetic-only repairs on structural cracks are why some homeowners see the same crack return within a year. We won't do that. If our repair fails inside 2 years, Jack comes back and fixes it free.

Yes — the cornice-junction crack (a horizontal crack running along where the cornice meets the wall or ceiling) is one of the most common Sydney plaster problems. Cause is usually cornice detachment from long-term thermal movement. Fix depends on cornice condition: if the cornice is sound we re-bond and skim; if the cornice is failing we replace the affected section and skim. Both approaches restore the profile invisibly.

Most single-room crack repairs are done in one visit — usually 2 to 4 hours including drying time between compound coats. Multi-room bundle jobs run half a day to a full day. If a crack needs a section cut-out and replaced (over 3mm or with sagging), we sometimes need a second visit 24-48 hours later for the final skim once the first coat cures properly.

For small cracks (under a metre), we blend the patch under your existing paint so well that touch-up painting the immediate area matches perfectly — you rarely need to repaint the whole wall. For longer repairs (2m+) or repairs across multiple walls, we recommend repainting the whole affected wall so the age and sheen match. We'll tell you honestly which approach makes sense for your job at the quote stage.

Yes — but they can wait if you have other priorities. Hairline cracks under 1mm are cosmetic and grow slowly. The reason to fix them: they tend to widen over 3-5 years, they collect grime and become more visible, and they're trivial to repair while small ($290 range) vs. much more expensive once they widen. If you're selling the house or repainting soon, bundle them into that work.

Federation, Victorian and Edwardian plaster walls (pre-1930 Sydney builds) need a different approach than modern gyprock. The original lime-and-horsehair plaster is more fragile and requires specialist handling — modern joint compound sometimes chemically rejects the old plaster surface. We use a bonding primer (Wattyl Plaster Bond or USG Tuff-Hide) between the old plaster and any modern repair layer. This preserves heritage character AND makes the repair invisible.