Quick Answer

Most plasterboard (Gyprock) repairs in Melbourne homes can be done with materials from a hardware store for $20–$80. Small holes under 50mm wide are filled with joint compound and sanded; larger holes need a patch or backing piece. The main challenge is matching the existing paint finish — budget an extra $30–$60 for touch-up paint, or plan to repaint the whole wall for a seamless result.

What You’ll Need

For Small Holes (Under 50mm)

  • Lightweight patching compound or ready-mix joint compound — $15–$25 (Parchem, USG, or Gyprock brand)
  • Putty knife or flexible filling knife (75–100mm) — $8–$15
  • Sandpaper — 120-grit and 180-grit — $5–$10
  • Self-adhesive fibreglass mesh patch (optional, for holes 20–50mm) — $12–$18
  • Primer/sealer for repaired area — $12–$20

For Large Holes (50mm–300mm)

  • Piece of 10mm or 13mm plasterboard (offcut from hardware store) — $8–$15
  • Timber backing pieces (19×38mm pine) — $5–$10
  • Corded drill or impact driver
  • 25mm plasterboard screws — $5
  • Joint compound and paper tape
  • Drywall saw or jab saw — $15–$25
Pro tip: Always use the same thickness of plasterboard as the existing wall — 10mm for internal walls, 13mm for ceilings and wet areas. Mixing thicknesses creates a lip at the join that shows through paint.

How to Repair a Small Hole (Under 50mm)

Step 1 — Clean the Hole

Remove any loose paper, crumbled plaster or protruding screws. For doorknob holes, press in any loose core material and let it dry. For screw pops, push the screw back in (or replace with a new 32mm plasterboard screw) and apply compound over the dimple.

Step 2 — Apply Mesh Patch (if needed)

For holes between 20–50mm, stick a self-adhesive fibreglass mesh patch over the hole. These are sold at Bunnings and Mitre 10 for $12–$18 and provide reinforcement for the compound.

Step 3 — Apply Joint Compound in Thin Coats

Apply ready-mix joint compound with a flexible filling knife, slightly overfilling the hole. Feather the compound out 50–80mm beyond the edges. Allow to dry completely (2–4 hours, longer in winter). Apply a second thin coat to compensate for shrinkage. For deep holes, three thin coats are better than one thick coat — thick applications crack as they dry.

Step 4 — Sand Smooth

Once fully dry, sand with 120-grit to remove ridges, then finish with 180-grit for a smooth surface. Wipe down with a damp cloth to remove dust. Sand in good lighting — a torch held at a low angle reveals any ridges that will show through paint.

How to Repair a Large Hole (50mm–300mm)

Step 1 — Cut a Clean Opening

Using a drywall saw, cut a clean rectangle around the damaged area. Extend the cut to the nearest stud on at least one side (studs are typically 450mm or 600mm apart — use a stud finder or knock to find the hollow/solid difference).

Step 2 — Install Timber Backing

Cut two pieces of 19×38mm pine slightly longer than the hole height. Hold them inside the wall cavity and screw through the existing plasterboard into the timber backing — this creates a fixing point for the patch piece.

Step 3 — Cut and Fix the Patch

Cut a piece of matching plasterboard to fit the opening. Screw it to the backing timber with 25mm plasterboard screws at 200mm intervals. Keep screw heads just below the surface (dimpled, not punched through).

Step 4 — Tape and Compound the Joins

Apply paper jointing tape over each joint, bedded into a thin layer of joint compound. Apply two or three additional coats of compound, feathering 150–200mm each side of the join. Sand smooth between coats.

Painting Over the Repair

Bare joint compound is highly porous and will absorb paint differently from the surrounding wall unless primed first. Apply one coat of water-based primer/sealer (Dulux Aquanamel or similar, $20–$35 for 1L) to the repaired area. Allow to dry, then sand lightly with 180-grit before top-coating.

Matching existing paint is the hardest part. If you have leftover paint from when the wall was last painted, use it. If not, take a photo of the wall and visit Dulux, Taubmans or the Bunnings paint counter for a colour match — $20–$40 for a 1-litre sample pot. For best results, repaint the full wall from corner to corner rather than spot-patching.

Troubleshooting

Problem Cause Fix
Compound cracking as it dries Applied too thick in one coat Allow to cure fully, then apply thin skim coat over cracks
Repair visible as bump under paint Not enough feathering, or skipped sanding Sand back and reapply compound, feathering wider
Paint soaks in unevenly (flashes) Skipped primer on bare compound Sand lightly, prime, then re-coat with paint
Tape bubbling under compound Not enough compound under tape when bedding Slice tape, re-bed with fresh compound, re-tape
Screws popping through wall surface Timber framing shrinkage Drive popped screw in further, add second screw 50mm below, fill both dimples

When to Call a Professional

Hire a plasterer or builder for: holes larger than 300mm, damage from water leaks (fix the leak first), ceilings (working overhead is difficult and messy), areas showing mould behind the plasterboard, or if you need a seamless invisible finish on a feature wall. A professional plasterboard patch costs $150–$400 depending on size and complexity.

Safety warning: Before cutting into any plasterboard wall, check for electrical cables and pipes. Use a stud-and-cable scanner (available for hire at Kennards for $25–$40/day) to scan the area before cutting. Never cut blindly into a wall — cables are not always run where you expect them.

Top 10 Tips and Gotchas

  1. Thin coats always. One thick coat of compound shrinks and cracks. Three thin coats of 1–2mm each produce a flat, hard finish.
  2. Sand in good light. A torch held at a low angle reveals imperfections invisible in flat overhead light. Do this before priming and before painting.
  3. Buy ready-mix, not powder. Ready-mix joint compound is easier to use for small jobs and won’t dry out mid-repair. Powdered setting compound (like Durabond) is stronger but sets irreversibly — not suitable for beginners.
  4. Moisture in walls = mould risk. If the plasterboard is soft, discoloured or smells musty, there’s a moisture problem behind the wall. Fix the source before patching — otherwise mould will return.
  5. Match the texture. Some Melbourne homes have textured (orange peel or skip trowel) walls. After patching, replicate the texture with a sponge or by stippling wet compound before it sets.
  6. Don’t skip primer on fresh compound. Unprimed compound flashes — the paint looks different on the repair than on the surrounding wall even after two coats.
  7. Ask for offcuts at the hardware store. Full sheets of plasterboard cost $25–$45. Many hardware stores have offcuts in the timber section for $5–$10 — perfect for small patch repairs.
  8. Screw pops are common in new homes. Timber framing shrinks as it dries, pushing screws back through the plasterboard face. This is normal in homes under 5 years old and is a quick fix.
  9. Fibreglass mesh patches are not suitable for large holes. Mesh patches are good to 50mm; larger holes need rigid backing and a plasterboard patch or the repair will crack over time.
  10. Repaint corner to corner. Spot-patching paint rarely matches exactly — the sheen and colour vary. For a clean result, repaint the entire wall between corners or to a natural break.

Local Melbourne Resources

Frequently Asked Questions

Can I use filler instead of joint compound for plasterboard repairs?

For very small holes (under 20mm), general-purpose filler (like Spakfilla) works fine. For larger repairs, use ready-mix joint compound specifically designed for plasterboard — it dries harder, sands more easily and is less prone to cracking on larger repairs. Avoid using exterior fillers or cement-based products on interior plasterboard.

How do I fix a doorknob hole in plasterboard?

A doorknob hole (typically 60–100mm) is best repaired with a peel-and-stick mesh patch for the smaller end, or a backing-and-patch method for larger holes. Apply compound in thin coats over the mesh, sanding between coats. Also install a door stopper to prevent the same damage recurring — a floor-mounted stopper costs $5–$15 at hardware stores.

How long does plasterboard repair take to dry?

Ready-mix joint compound takes 2–4 hours per coat in warm weather, 4–8 hours in winter. Allow each coat to dry completely white (not still grey) before applying the next coat or sanding. Rushing the drying time causes the compound to crack or shrink unevenly. In Melbourne winters, a fan heater in the room speeds drying significantly.

Why does my paint look different over the repaired area?

The most common cause is skipping primer over bare compound. Joint compound is highly porous and absorbs the first coat of paint completely, leaving a flat “dead” patch compared to the sheen on the surrounding painted wall. Always apply a water-based primer/sealer to bare compound before top-coating, and apply two full coats of your top-coat paint.