Why Mould is a Common Problem in Newcastle
Newcastle's humid coastal climate creates ideal conditions for mould and mildew growth on painted surfaces — particularly on south-facing walls, in shaded areas and on surfaces that stay damp.
Identifying Mould vs. Dirt
Mould appears as dark grey, black or green spotting that grows in irregular patches. It won't wash off with plain water. A dilute bleach solution (1 part bleach to 3 parts water) will kill mould — dirt won't react the same way.
Can You Paint Over Mould?
No. Painting over mould is one of the most common — and costly — mistakes. The mould continues growing under the new paint, eventually pushing it off the surface.
Treatment Process
- Scrub with a dilute bleach solution and stiff brush
- Rinse thoroughly and allow to dry completely (2–3 days minimum)
- Apply a mould-inhibiting primer or undercoat
- Apply topcoat with mould inhibitor
Prevention for New Paint Jobs
Specify a paint with built-in mould inhibitor for any moisture-prone areas. Good ventilation — particularly inside — is the other key factor.
Interior Mould Warning
Interior mould (bathrooms, laundries, behind furniture) is often a sign of a moisture or ventilation problem, not just a painting issue. Address the underlying cause before repainting.