Sydney Wide Plastering is your team of Complete Interior Specialists when you need plastering or a gyprocking completed in Sydney and Sydney’s northern beaches. We are your first choice.
You patch the crack, repaint the wall, and it looks perfect. Then a few months later, there it is again, same spot and same line. The problem is that the crack itself is just a symptom. You can patch the surface as many times as you like, but if the underlying cause remains, the crack will eventually reopen.
In this blog, we'll look at the most common reasons gyprock cracks keep coming back and how to identify the cause.
Gyprock, also known as plasterboard or drywall, creates the solid surface you see on your walls and ceilings. It is fixed to a timber or steel frame, so when the structure behind it shifts, even slightly, stress builds up at the joints where the sheets meet. Over time, that stress can cause the joint compound to crack.
Many people assume filling the crack will solve the problem. Sometimes it does, but only when the movement that caused the crack has stopped. If the wall, ceiling, or frame continues to move, the crack will eventually return.
This is a common issue in many homes. That is why proper repairs start with identifying what is causing the crack in the first place, rather than simply patching over it.
Most homes in Sydney are built with timber framing. Timber naturally expands and contracts as humidity levels change throughout the year. This movement places pressure on gyprock joints, especially around doors, windows, and ceiling corners. If a crack seems to appear during winter and become less noticeable in summer, seasonal movement is the reason.
Water is one of the most common causes of recurring cracks. Leaking roofs, faulty shower waterproofing, overflowing gutters, and poor ventilation can all allow moisture into the wall cavity. As the plasterboard absorbs and releases moisture, it expands and shrinks, eventually causing joints to crack. Water stains, damp smells, or soft patches on the wall are signs that moisture is the real issue.
Areas exposed to strong sunlight or frequent temperature changes can experience repeated expansion and contraction. This is common in north-facing rooms, spaces with skylights, and ceilings above kitchens where heat builds up. As time goes on, this repeated movement can place stress on plasterboard joints, causing hairline cracks to reappear along joint lines.
Sometimes the problem starts with the installation. If the tape was not properly embedded or the joints were rushed during construction, cracks can appear after the work is completed. This is very common in new homes where finishing work was not completed to a high standard.
Sydney's reactive clay soils can cause foundations to move as the ground becomes wetter or drier throughout the year. When this happens, the building frame shifts slightly, and the stress can show up as cracks in the gyprock. Diagonal cracks around doors and windows are one of the most common signs of foundation movement.
If your home is close to a busy road, train line, or construction site, constant vibration can gradually loosen fixings and create movement within the plasterboard system. While the vibration is not obvious day to day, it can still contribute to cracks.
Using the wrong filler, skipping reinforcement tape, and painting before the repair has fully cured can all lead to the crack returning. In many cases, the crack comes back because the underlying cause was never addressed in the first place.
These are usually caused by seasonal movement as building materials expand and contract with changes in temperature and humidity. They are cosmetic rather than structural. A filler followed by repainting is enough, but it is worth keeping an eye on the crack for several months to ensure it does not grow.
When a crack appears where the wall meets the ceiling and the cornice begins to separate, it can indicate roof truss movement or changes in humidity levels. These cracks are common in many homes and are not always a sign of major structural issues. A flexible sealant can help reduce the chance of the crack reopening, but the area should still be monitored through seasonal changes.
Diagonal cracks that extend from the corners of doors or windows are a sign of movement in the home's foundations, especially if they continue to widen. These cracks indicate that something deeper within the structure is shifting. Before repairing the surface, it is important to identify the cause and have it assessed by a qualified professional.
If a crack is accompanied by yellow or brown staining, moisture is likely entering the wall or ceiling cavity. The source of the leak should be identified and repaired before any plastering work is undertaken. Once the area is fully dry, the damaged gyprock can be repaired or replaced as required.
Large cracks accompanied by doors or windows that have become difficult to open or close indicate structural movement within the building. In these situations, cosmetic repairs should be avoided until the underlying cause has been investigated.
Small hairline cracks can be repaired as a DIY project. However, when cracks keep returning or show signs of a bigger underlying issue, it is worth having them assessed by a professional.
Consider calling a qualified gyprocker in Sydney if:
If a crack keeps coming back, there is usually an underlying issue that has not been properly addressed.
A lasting repair starts with identifying the cause rather than simply filling the crack. Once the underlying issue has been resolved, the right repair method can restore the wall or ceiling and help prevent the crack from returning.
If you are unsure what is causing a crack or if it keeps reappearing after repairs, professional advice can help you avoid repeated patch jobs and unnecessary expense.
At Sydney Wide Plastering, we have spent more than 30 years helping homeowners with everything from minor repairs to larger restoration projects. To speak with our team, call 0405 847 224 or complete our online form.
