Plasterboard wall repair may seem like a straightforward job, but it’s surprisingly easy to get wrong—especially if you’re tackling it for the first time. Many homeowners attempt a DIY fix, only to end up with lumpy finishes, visible seams, or recurring cracks that ruin the aesthetics of their home.
This guide explores five of the most common mistakes people make when repairing plasterboard walls. From choosing the wrong materials to rushing through the process, each misstep can affect the durability and appearance of your repair. The good news? Every mistake is avoidable with the right information and a bit of preparation.
By understanding these pitfalls and how to steer clear of them, you can ensure your walls are not just patched—but properly restored.
Mistake #1: Using the Wrong Filler or Compound
The first and most common error in wall repair is selecting the wrong product to patch the surface. There are different types of compounds—each with their own strengths and purposes. Using the wrong one can result in shrinking, cracking, or poor adhesion.
For small dents and nail holes, lightweight spackle or pre-mixed filler is generally fine. But for anything larger than a 5-cent coin, you’ll need joint compound or a patching compound that dries solid and can be sanded smooth.
Some DIYers mistakenly reach for fast-drying fillers, thinking quicker is better. However, these products can dry too quickly, leading to brittle patches that crack with the slightest movement or temperature change.
Tip: For areas larger than a few centimetres, use a joint compound and apply it in thin layers, allowing each coat to dry before the next. This prevents sinking and cracking later.
When working with gyprock wall installation, choosing the right compound becomes even more important. Since gyprock is a common interior wall surface in Australia, ensuring proper filling, joining, and finishing is key to a smooth, seamless finish. Using the correct joint compound and proper layering technique helps maintain the integrity of the gyprock panels and ensures a professional result.
Mistake #2: Failing to Sand Properly
If your repair still stands out after painting, poor sanding is likely to blame.
Sanding is crucial to blending the repaired area seamlessly with the rest of the wall—especially in plasterboard wall repair, where the surface needs to be perfectly smooth to match surrounding areas. Common sanding mistakes include:
- Over-sanding: This can gouge the patch and expose the plasterboard underneath, making it harder to conceal.
- Under-sanding: Leaves behind lumps or ridges that show through paint.
- Skipping feathering: Results in hard edges around the patch that are easily noticeable once painted.
For best results, use a sanding block or pole sander with 120 to 150-grit sandpaper. Apply light, even pressure and focus on feathering the edges so the patch fades naturally into the wall.
Tip: Run your fingers over the patched area with your eyes closed—if you feel a bump or ridge, keep sanding. Smooth transitions are essential for a professional-looking plasterboard wall repair.
Mistake #3: Skipping the Primer Before Painting
It might feel like an optional step, but priming patched areas before painting is essential if you want an even, professional finish—especially after repairing holes in wall surfaces.
Plasterboard compound is porous and absorbs paint differently than the surrounding wall. Without primer, you risk:
- Blotchy paint finish
- Uneven colour tone
- Reduced paint durability
Use a stain-blocking primer or a plasterboard-specific sealer. These products ensure better paint adhesion and help the topcoat cover evenly by sealing the repaired area.
Tip: If you’re painting an entire wall, apply primer over the whole surface—not just the patch—for smooth, consistent coverage.
Mistake #4: Not Reinforcing Larger Repairs
Many homeowners attempt to fill large holes in plasterboard using only compound. While it might appear fine at first, the repair can later sag, crack, or crumble under minimal pressure.
Repairs larger than about 5cm in diameter need reinforcement to stay structurally sound. Options include:
- Adhesive mesh tape: Prevents cracks from forming at seams or where the filler meets the existing wall.
- Backing boards (plasterboard or timber batten): These support larger holes and prevent the filler from collapsing.
Tip: For large patches, secure a small board behind the hole to screw in the new plasterboard piece. Then tape and fill around the edges.
Mistake #5: Rushing the Job Without Letting Layers Dry
It’s tempting to breeze through repairs in a single afternoon, but plasterboard compound needs time to cure properly.
Each layer of compound—especially in deeper patches—needs to fully dry before the next one goes on. Rushing can cause:
- Bubbling
- Cracking
- Uneven drying
- Poor sanding results
Drying time varies with humidity and temperature. In some cases, it may take overnight or longer.
Tip: If you’re in a hurry, use a setting-type joint compound that hardens within 20–90 minutes, but be prepared to sand carefully—these dry harder and are less forgiving.
Bonus Tips for a Professional Finish
- Clean the wall before starting to remove dust, dirt or grease that can affect adhesion.
- Use a dust brush or vacuum after sanding to clear fine powder before painting.
- Use light layers of paint and a roller to blend the patched area with the rest of the wall.
- Inspect with a torch at an angle—this highlights imperfections you might miss under regular lighting.
These small touches can make the difference between a passable fix and a flawless wall.
Conclusion
Plasterboard repairs don’t have to be intimidating—but they do require attention to detail and patience. Avoiding common mistakes like choosing the wrong filler, skipping primer, or rushing the job ensures a longer-lasting, better-looking repair.
By understanding these five key pitfalls and following best practices, you can repair your walls confidently and professionally—without calling in a tradie.
