Why do cracks appear in plaster?
Short answer: Cracks can be caused by movement in the substrate, moisture, wrong materials or temperature changes.
To choose the right fix, the crack type and scope must be assessed.
Hairline cracks
Small, thin cracks can be cosmetic but may also indicate movement or drying.
Larger cracks
Larger cracks can let in moisture. It is important to check the substrate and seal correctly.
Moisture and frost damage
Water that gets in can freeze and damage the plaster. This is a common cause of cracks and detachment.
Wrong materials
If the wrong mortar is used, plaster can become too hard or too dense. This increases crack risk—and can also worsen moisture issues. Read more: lime mortar vs cement.
When should you fix it?
If cracks grow, loosen or let in moisture, they should be addressed. We can assess.
How it works
We assess on site and recommend the right method: local repairs, re-rendering or reinforcement. The goal is a fix that lasts—not just hiding a crack. We can help with plastering and repairs.
Book an assessment
Describe the cracks (photos help) and we’ll get back with next steps. Contact us here. Read more about us on the homepage.
