Ask the Expert: Tackling Mould, Limewash, and the Practical Side of DIY Painting

Resene expert Jay Sharples answers top DIY questions on mould-resistant ceilings, professional limewashing techniques, and how to handle fresh paint.

By: AXL Media

Published: Apr 7, 2026, 5:41 AM EDT

Source: Stuff

1. Combatting Ceiling Mould

Mould in damp areas like bathrooms and laundries is a common frustration. To keep ceilings clean and healthy, the approach must be two-fold:

Treatment: Before painting, you must kill existing spores using a cleaner like Resene Moss & Mould Killer. Painting over live mould will only cause it to grow behind the new layer.

Prevention: Use specialized coatings like the Resene Kitchen & Bathroom range, which contains a built-in mould defender. For poorly ventilated areas, a waterborne-alkyd hybrid like Resene Room Velvet is often the superior choice.

Ventilation: Expert advice reminds homeowners that paint is only part of the solution; proper extraction fans and heating are essential for long-term mould prevention.

2. Achieving the Professional Limewash Look