What tools do I need for repair holes and cracks in plasterboard before painting?

This guide includes a comprehensive tools list. Key painting & decorating tools are detailed in the Tools Required section.

What is the Australian standard for finishing plasterboard walls?

The Australian standard for finishing plasterboard before painting is AS/NZS 2589:2017. This standard specifies a Level 4 finish as the minimum requirement for walls receiving non-critical flat or low-sheen paints. A Level 4 finish mandates that all joints, interior angles, and fastener heads receive three compound coats feathered out smoothly to prevent surface flashing.

Why must you prime plasterboard patches before painting?

You must prime plasterboard patches before painting to equalise surface porosity across the repair. Plasterboard joint compounds are significantly more porous than factory face paper. Applying a dedicated primer-sealer or pigmented sealer undercoat prevents the topcoat binder from soaking into the filler, which stops suction differences and eliminates flashing or glossy band marks under raking light.

How do you repair a crack in plasterboard to prevent it returning?

To repair a plasterboard crack permanently, rake out loose core material with a utility knife to form a shallow V-groove. Bed paper joint tape or self-adhesive fibreglass mesh tape into a base-setting compound like Gyprock Base Coat 45. Apply two subsequent feathering coats using a 150mm broadknife before final sanding with 180-grit abrasive paper.

What PPE is required when sanding plasterboard filler in Australia?

SafeWork Australia mandates respiratory and eye protection during dry sanding of gypsum joint compounds. Workers must wear a properly fitted P2 particulate respirator compliant with AS/NZS 1716 to prevent inhalation of respirable gypsum and silica dust. AS/NZS 1337-compliant safety spectacles or goggles and drop sheets for dust containment are also required.

How to repair holes and cracks in plasterboard before painting

Flawless interior paint finishes rely entirely on seamless wall preparation. Whether repairing minor picture hook holes, door handle dents, or hairline settlement cracks, executing plasterboard repairs correctly prevents unsightly flashing and cracking down the track. This guide walks you through tr

Quick answer

To repair holes and cracks in plasterboard before painting, clear loose core material, apply a base compound reinforced with joint tape, and finish with a feathered topping layer. Sand flush with 180-grit paper, then apply a dedicated primer-sealer to achieve an AS/NZS 2589 Level 4 finish and prevent topcoat flashing.

Skill level: Beginner
Time: 2-4 hours active work (plus 2-4 hours drying time)
Trade: Painting & Decorating
Updated: 6 November 2026

Tools you will need

🔧 Equipment Required
50mm
150mm
Sanding block or pole sander with 180
Utility knife
Drop sheets
Microfibre dusting cloth
230mm microfibre roller setup

🎨 Complete Guide: Repairing Holes and Cracks in Plasterboard Before Painting

Why is proper plasterboard preparation essential before painting?

Skill Level

Beginner — Estimated time: 2-4 hours active work (plus 2-4 hours drying time)

What tools and equipment are required to repair plasterboard walls?

🔧 Equipment Required 50mm (2") and 100mm (4") flexible stainless steel filling blades 150mm (6") broadknife (for feathering larger patches) Sanding block or pole sander with 180-grit and 240-grit sandpaper Utility knife (snap-off blade) Drop sheets (canvas or plastic-backed) Microfibre dusting cloth 230mm microfibre roller setup (10-12mm nap) and sash cutter brush for priming

Which compounds, tapes, and primers are needed for patching plasterboard?

Gyprock Rapid Patch or Selleys Spakfilla Rapid (for pinholes and shallow dents) Gyprock Base Coat 45 or CSR Base Coat (for deeper gouges or structural cracks) Self-adhesive fibreglass mesh tape or paper joint tape (for active cracks and large patches) Perforated metal patch or backer timber (for door handle holes larger than 50mm) Dulux 1Step Prep or Taubmans 3-in-1 Interior/Exterior Primer Sealer Undercoat Estimated material cost: $10–$15 per m² of repaired area

What safety precautions and PPE are required when sanding plasterboard?

⚠️ Safety: Wear a P2 disposable respirator and safety glasses during dry sanding to protect against airborne gypsum dust. Test for lead-based paint on homes constructed prior to 1970 using a rapid chemical test kit before sanding existing substrates (refer to AS 4361.2 Guide to hazardous paint management). Ensure adequate cross-ventilation in small spaces like hallways and powder rooms.

Step-by-Step Guide

1️⃣ Assess and Prepare the Damage

Inspect the area thoroughly. For small screw holes and nail pops, cut away any protruding, frayed face paper using a sharp utility knife to create a clean, recessed bevel. For hairline cracks, use the corner of your filling blade to rake out the crack slightly into a shallow "V" profile, removing loose debris and powdery plaster.

2️⃣ Reinforce Settlement Cracks (If Required)

If addressing hairline cracks wider than 1mm or movement cracks along sheet joints, apply self-adhesive fibreglass mesh tape directly over the centre of the crack. Without tape reinforcement, building movement will cause standard filler to crack again within weeks.

3️⃣ Apply Base Filler (First Coat)

Mix a small batch of Gyprock Base Coat or scoop out Selleys Spakfilla Rapid. Holding your 100mm blade at a 45-degree angle, press the compound firmly into the void, ensuring zero air pockets remain behind the patch. Draw the blade tight across the wall to leave the compound flat or marginally proud of the surface. Allow 1-2 hours drying time.

4️⃣ Second Coat & Feather the Edges

For larger patches and taped joins, apply a thin second coat of finishing compound using a 150mm broadknife. Extend the compound 50-75mm past the edges of the first coat, feathering the edges flat against the surrounding wall by applying more pressure to the outside edge of your blade. Allow 2-4 hours drying time until completely hard and chalk-white.

5️⃣ Sand to a Seamless Finish

Attach 180-grit abrasive paper to your sanding block. Using gentle, circular strokes, sand the perimeter of the patch first to blend the transition, then gently flat-sand the centre. Finish with 240-grit paper to remove sanding scratches. Run your bare hand across the patch with your eyes closed—if you can feel an edge or hollow, it will show through the paint. Wipe off all residual dust with a damp microfibre cloth.

6️⃣ Seal and Undercoat (Crucial)

Never paint topcoats directly over raw filler, as porous plaster causes severe patchiness and sheen variation ("flashing"). Apply one coat of Dulux 1Step Prep or Taubmans 3-in-1 across the entire repaired area, feathering the paint 100mm past the repair. Achieve standard coverage of 12-14m²/L and allow 2-4 hours recoat time before applying interior topcoats like Dulux Wash&Wear or Taubmans Endure.

Common Mistakes to Avoid

1.Skipping primer-sealer: Applying topcoat directly to bare filler leads to binder absorption, leaving a visible, dull patch (flashing) under raking light.

2.Overfilling in one thick pass: Piling filler on too thick causes deep cracking, shrinkage hollows, and excessive sanding time. Build up deep voids in two thin layers.

3.Leaving frayed plasterboard paper: Paint and filler will not stick cleanly to torn, loose plaster paper; failure to trim it causes blisters under the patch.

4.Using high-grit, rough sandpaper: Coarse sandpaper (under 120-grit) tears the plasterboard facing paper and leaves gouges that telegraph through low-sheen wall paints.

Pro Tips
💡 Pro tip: Surface prep is always 80% of the job — take extra time feathering edges during sanding, because paint only highlights flaws rather than hiding them. 💡 Check your sanding quality using a handheld trade work light held parallel to the wall (raking light) to reveal subtle ridges and dips before priming. 💡 When feathering with a broadknife, place your index finger near the outer edge of the blade to apply uneven pressure, keeping the outer perimeter tissue-thin.

Recommended Tools

Marshalltown 150mm Stainless Steel Broadknife: Essential trade tool with flexible blade edge control for feathering compounds seamlessly into surrounding plaster. Mirka Handy Dustless Sanding Block: Hooked up to a standard vacuum, this cuts down 90% of fine plaster dust in domestic living rooms.

Selleys Spakfilla Rapid (Tub): High-grade, fast-drying lightweight filler formulated to resist shrinking and cracking for holes under 10mm deep.

Frequently asked questions

What is involved in repair holes and cracks in plasterboard before painting?: Flawless interior paint finishes rely entirely on seamless wall preparation. Whether repairing minor picture hook holes, door handle dents, or hairline settlement cracks, executing plasterboard repairs correctly prevents unsightly flashing and cracking down the track. This guide walks you through tr
What skill level do I need for repair holes and cracks in plasterboard before painting?: Beginner — Estimated time: 2-4 hours active work (plus 2-4 hours drying time)
What are common mistakes when repair holes and cracks in plasterboard before painting?: 1. Skipping primer-sealer: Applying topcoat directly to bare filler leads to binder absorption, leaving a visible, dull patch (flashing) under raking light. 2. Overfilling in one thick pass: Piling filler on too thick causes deep cracking, shrinkage hollows, and excessive sanding time. Build up deep voids in two thin layers. 3. Leaving frayed plasterboard paper: Paint and filler will n
What tools do I need for repair holes and cracks in plasterboard before painting?: This guide includes a comprehensive tools list. Key painting & decorating tools are detailed in the Tools Required section.
What is the Australian standard for finishing plasterboard walls?: The Australian standard for finishing plasterboard before painting is AS/NZS 2589:2017. This standard specifies a Level 4 finish as the minimum requirement for walls receiving non-critical flat or low-sheen paints. A Level 4 finish mandates that all joints, interior angles, and fastener heads receive three compound coats feathered out smoothly to prevent surface flashing.
Why must you prime plasterboard patches before painting?: You must prime plasterboard patches before painting to equalise surface porosity across the repair. Plasterboard joint compounds are significantly more porous than factory face paper. Applying a dedicated primer-sealer or pigmented sealer undercoat prevents the topcoat binder from soaking into the filler, which stops suction differences and eliminates flashing or glossy band marks under raking light.
How do you repair a crack in plasterboard to prevent it returning?: To repair a plasterboard crack permanently, rake out loose core material with a utility knife to form a shallow V-groove. Bed paper joint tape or self-adhesive fibreglass mesh tape into a base-setting compound like Gyprock Base Coat 45. Apply two subsequent feathering coats using a 150mm broadknife before final sanding with 180-grit abrasive paper.
What PPE is required when sanding plasterboard filler in Australia?: SafeWork Australia mandates respiratory and eye protection during dry sanding of gypsum joint compounds. Workers must wear a properly fitted P2 particulate respirator compliant with AS/NZS 1716 to prevent inhalation of respirable gypsum and silica dust. AS/NZS 1337-compliant safety spectacles or goggles and drop sheets for dust containment are also required.

Written by Painter, the Painting & Decorating specialist at VIC.Tools.