CRACKS IN PLASTER: TYPES, CAUSES, AND SOLUTIONS

Cracks in Plaster: Types, Causes, and Solutions

Cracks in Plaster: Types, Causes, and Solutions

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ceiling or wall Cracks in Plaster

Cracks in plaster are a common issue in homes and buildings, and they can be concerning if you’re unsure of their cause. Some cracks are harmless, while others might indicate bigger problems that need professional attention.

By understanding the types of cracks—hairline, settlement, and delaminating—you can figure out what’s happening and how to fix it. Here’s a straightforward guide to help you.

Types of Cracks


Hairline Cracks

  • What they look like: Very thin cracks, usually less than 0.1 mm wide. You’ll often spot them running across the surface of the plaster.

  • What causes them: Hairline cracks usually happen because of minor movements in the building, drying plaster shrinkage, or changes in temperature and humidity. For example, as the seasons change, materials can expand and contract slightly, causing the plaster to crack.

  • Should you worry?: These cracks are mainly cosmetic. They don’t usually mean there’s a bigger problem, but if you notice them spreading or deepening, it might be time to investigate further.


Settlement Cracks

  • What they look like: These cracks are usually larger than hairline cracks and can appear as vertical lines or fissures in the plaster.

  • What causes them: Settlement cracks happen when a building’s foundation shifts or settles over time. This is pretty normal, especially in older houses. Factors like soil movement, moisture changes, and natural settling can all contribute to these cracks.

  • Should you worry?: Small settlement cracks aren’t unusual, but if they’re growing, widening, or causing other damage, it’s a good idea to get a professional to check the foundation. Significant cracks could mean there’s a structural issue that needs fixing.


Delaminating Cracks

  • What they look like: These cracks make it look like the plaster is pulling away or separating from the wall underneath. You might even notice some of the plaster feels loose or sounds hollow when you tap it.

  • What causes them: Poor adhesion is the main culprit here. This can happen if the wall surface wasn’t prepared properly before plastering or if low-quality materials were used. Moisture damage can also make the problem worse by weakening the bond between the plaster and the wall.

  • Should you worry?: Yes, delaminating cracks can affect the strength of the plaster. If left untreated, the plaster could eventually fall away. Fixing this involves removing the loose plaster and applying new plaster properly to ensure a solid bond.


Common Causes of Cracking


Cracks in plaster happen for a variety of reasons:

  • Building Movement: All buildings move slightly as they settle over time, which can put stress on plaster surfaces.

  • Temperature and Humidity Changes: Fluctuations in temperature cause materials to expand and contract, leading to cracks.

  • Moisture Damage: Water leaks or excess moisture can weaken the plaster, causing it to crack or separate from the wall.

  • Vibrations: Vibrations from nearby traffic, construction, or heavy machinery can also contribute to cracking, especially in older or weakened plaster.


How to Fix Cracks in Plaster



  • Hairline Cracks: These are easy to fix with a bit of filler. Simply fill the crack, sand it smooth, and repaint the area to make it look as good as new.

  • Settlement Cracks: Keep an eye on these cracks. If they’re not growing, you can patch them up like hairline cracks. If they’re getting worse, it’s best to get a professional to assess the foundation and recommend repairs.

  • Delaminating Cracks: These require more work. The loose plaster needs to be removed, and the wall surface must be properly cleaned and prepared before applying new, high-quality plaster.


When to Call a Professional


If you’re unsure about a crack, it’s always better to be safe and call in a professional. They can assess whether the crack is cosmetic or structural and recommend the best solution.

Regular maintenance and inspections can also help catch issues early, saving you time and money in the long run.

Cracks in plaster can be unsightly, but not all of them are cause for alarm. Hairline cracks are usually harmless, but settlement and delaminating cracks may require more attention.

If you're concerned, it’s a good idea to contact a plasterer Mandurah with Southern Ceiling Repairs to ensure your walls stay in top shape and your home remains safe. If in doubt, don’t hesitate to get professional advice to sort it out properly.

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