Bathrooms & Ensuites: How to Keep Mould Out!
Moisture control is the single biggest factor in preventing mould—and in a bathroom, a few simple habits make a major difference.
Why squeegeeing your shower matters
After showering, water sits on tiles, glass, grout, and silicone. Those damp surfaces can stay wet for hours—exactly what mould needs to establish.
Squeegeeing removes that residual water immediately, which:
- Speeds up drying time
- Reduces moisture absorption into porous materials
- Limits the conditions mould needs to grow
- Prevents the buildup of organic films mould feeds on
It’s a simple habit that significantly reduces overall “wet time.”
Why keeping bathroom doors closed is important
A hot shower releases a large volume of humid air. If the door is open, that moisture spreads into bedrooms, wardrobes, and other cooler areas where it condenses on:
- Walls and ceilings
- Windows and furnishings
- Inside wardrobes
Keeping the door closed:
- Contains moisture to one controlled space
- Allows ventilation systems to work effectively
- Prevents hidden moisture buildup in adjoining rooms
Why extractor fans are essential
An extractor fan removes moisture at the source—but only if used properly. Running it during and well after showering (until the room is fully dry) will:
- Remove humid air before it settles
- Reduce condensation
- Accelerate drying
- Lower overall indoor humidity
Without proper extraction, moisture lingers—even if surfaces appear dry.
Why the fan must be ducted outside
If a fan vents into the roof cavity, it doesn’t remove moisture—it relocates it. This leads to:
- Condensation on timber framing and insulation
- Hidden mould growth
- Potential structural damage over time
A properly ducted system expels moisture outside, keeping both the bathroom and roof cavity dry.
Why mould can’t be fully removed from silicone or grout
Silicone and traditional cement-based grout are porous materials. Once mould establishes, its roots (hyphae) penetrate below the surface:
- Cleaning only removes surface staining, not the embedded growth
- Mould will often return, even after repeated treatments
- Discolouration in silicone is usually permanent
In most cases, affected silicone and standard grout need to be replaced—not cleaned.
Why epoxy grout is more effective
Unlike standard grout, epoxy grout is non-porous and highly resistant to moisture absorption:
- Prevents water from penetrating below the surface
- Doesn’t provide a food source for mould
- Is far easier to clean and maintain
- Significantly reduces long-term mould risk
It’s a far more durable, mould-resistant solution for wet areas.
The bottom line
Mould thrives on persistent moisture and porous surfaces.
By combining good habits with better materials, you can dramatically reduce the risk:
- Remove water quickly (squeegee)
- Contain humidity (keep doors closed)
- Extract moisture properly (ducted fans)
- Eliminate porous problem areas (upgrade grout where possible)
These small, consistent actions prevent both visible mould and the hidden issues that often lead to costly remediation.