Industry Insights

Why Wall Cracks Keep Reappearing and How a Plasterer Can Fix Them

Written by Marie Julian | May 2, 2025 6:47:01 AM

You've patched it, painted over it, and hoped it wouldn’t come back—but it did. Again. Repeating wall cracks are one of the most frustrating things a homeowner can face. If you're wondering why your walls keep splitting or flaking and how to put a stop to it for good, you're not alone.

Let’s take a look at the real reasons behind persistent cracking and why hiring a professional plasterer is often the best way to get lasting results.

1. Why Do Wall Cracks Keep Reappearing?

Wall cracks can return for a number of reasons—some more serious than others. While not all cracks mean structural issues, they’re often symptoms of poor installation or movement beneath the surface. Common causes include:

• Inadequate Surface Preparation

If the wall wasn’t properly cleaned, primed, or keyed before plaster was applied, the bond can fail over time. Even minor cracks can form when surfaces aren't ready to take on new material.

• Incorrect Plaster Application

Plaster that's applied too thick or too thin can dry unevenly or become brittle. There’s a recommended thickness for a reason: going outside of it can lead to crazing or larger splits down the track.

• Lack of Reinforcement

Hairline cracks can form naturally as plaster cures, especially on larger areas. But without mesh tape or appropriate reinforcement over joints or problem zones, small cracks can quickly return or spread.

• Speed Drying or Suction Issues

Turning on the heating to "help" plaster dry? That could be doing more harm than good. Fast drying causes surface cracks known as crazing. Similarly, strong suction from the wall surface can pull moisture out too fast, weakening the plaster.

• Poor Adhesion to the Substrate

Tap gently on the wall with your knuckles or fingernails. If it sounds hollow, the plaster might not be properly bonded underneath—and that’s a common cause of reappearing cracks.

• Movement in the Structure

Timber framing, shifting studs, and minor building movement can all cause stress behind your walls. Without flexible or reinforced plastering, cracks will often follow these fault lines.

2. Not All Cracks Are Equal

While some small hairline cracks are purely cosmetic, others signal a deeper issue.

  • Hairline cracks in lime plaster are relatively normal. If you can’t get your fingernail into the crack, it might not be worth worrying about.
  • Wider, deeper cracks or cracks that keep reappearing in the same location should be inspected by a professional.

It’s important not to guess. A qualified plasterer can distinguish between harmless shrinkage and something that might require more serious repair.

3. Why Paint Isn’t the Solution

It might be tempting to paint over cracks and call it done. And yes, paint might hide hairlines temporarily. But if the issue lies beneath the surface, the crack will return—and it usually brings friends.

Paint doesn’t fix the bond between plaster layers or solve curing issues. It's simply a cover-up, not a cure.

4. How a Plasterer Can Fix It—For Good

A trained plasterer does far more than patch and fill. Here's how they ensure your wall crack repair actually lasts:

• Proper Assessment

They’ll check whether the plaster is hollow or sound, test the suction of the wall, and inspect for movement or substrate issues.

• Cutting Out and Filling

Rather than slapping on filler, a good plasterer will widen the crack slightly, apply mesh tape if needed, and use compatible materials for a flexible, long-lasting repair.

• Re-skimming Where Needed

For larger areas or extensive damage, a full re-skim might be the most reliable fix. Skimming creates a smooth, reinforced surface ready for a fresh coat of paint.

• Correct Thickness and Technique

There's no such thing as a “light skim.” Professional plasterers apply plaster at the right thickness—generally around 2-3mm—with controlled drying conditions for a solid, smooth finish.

5. Beware of Cowboy Jobs

Unfortunately, not everyone calling themselves a plasterer has the skills or training. Poor workmanship is one of the most common reasons for cracking in the first place.

Signs of a bad job include:

  • Uneven finish
  • Visible tool marks
  • Thin application
  • Cracking soon after drying
  • Patches that sound hollow when tapped

Hiring an experienced plasterer through a trusted platform like ServiceSeeking.com.au helps you avoid the stress of repeat repairs.

6. When to Act

If you’re noticing any of the following, it’s worth getting a professional to take a look:

  • Cracks wider than a credit card
  • Cracks that keep returning after patching
  • Cracks around windows or doors
  • Flaking or hollow-sounding areas
  • Movement-related signs (doors sticking, uneven floors)

Don’t wait until cosmetic issues become structural problems. A quick assessment can save you time, money, and a lot of repainting.

Call-Out: Don’t Let Wall Cracks Win

Wall cracks aren’t just annoying—they’re often signs something needs attention. A professional plasterer can not only fix the symptoms, but address the root cause for lasting peace of mind.

Find a reliable local plasterer today on ServiceSeeking.com.au and finally say goodbye to recurring wall cracks—for good.