Bathrooms That Never Fully Dry

Bathrooms That Stay Damp: Why Moisture Lingers and How Proper Ventilation Fixes It

What the Problem Is

Some bathrooms never seem to fully dry. Mirrors stay foggy long after showers, towels feel damp, paint peels, and mould begins to form on ceilings, grout, and silicone.

Even bathrooms with a fan installed can suffer from ongoing dampness, leaving the space feeling cold, clammy, and unhealthy.

Why Bathrooms Stay Damp

Bathrooms produce the highest moisture load in the home. A single hot shower can release litres of water vapour into the air.

Bathrooms struggle to dry properly when:

  • Exhaust fans are undersized or poorly located
  • Fans are too noisy, so they’re switched off early
  • Moist air isn’t vented outdoors
  • There is no make-up air, so extraction is ineffective
  • The home is airtight and moisture has nowhere to escape

In many homes, moisture spreads from the bathroom into bedrooms and living areas, increasing condensation and mould risk throughout the house.

How Ventilation Allows Bathrooms to Dry Properly

Ventilation fixes damp bathrooms by removing moist air at the source and preventing it from spreading.

Effective ventilation:

  • Extracts steam during and after showers
  • Lowers humidity so surfaces can dry
  • Reduces mould and mildew growth
  • Protects paint, plaster, and fixtures

For a bathroom to dry properly, ventilation must be powerful enough, quiet enough, and run for long enough.

Recommended Ventilation Systems

1. High-Quality Bathroom Exhaust Fans

A well-designed bathroom exhaust fan is the most direct and effective solution for damp bathrooms.

High-quality fans:

  • Move sufficient air to remove steam quickly
  • Are quiet enough to run during and after showers
  • Vent directly outdoors, not into roof spaces
  • Can be paired with timers or humidity sensors for extended run time

Correct fan sizing, ducting, and termination are just as important as the fan itself. A poorly installed fan will struggle to remove moisture, even if it is powerful on paper.

2. Heat Recovery Ventilation (HRV/ERV) Systems

HRV and ERV systems provide whole-home ventilation, with continuous extraction from wet areas such as bathrooms, laundries, and kitchens.

They are particularly effective because they:

  • Extract moisture from bathrooms automatically
  • Prevent damp air spreading through the home
  • Operate continuously, not just during showers
  • Maintain balanced airflow in airtight homes

By extracting moisture consistently across all wet areas, HRV/ERV systems help bathrooms dry faster while also improving air quality throughout the home.

Other Helpful Fixes (Non-Ventilation)

Ventilation is essential, but these measures can support better drying:

  • Use exhaust fans for at least 20–30 minutes after showers
  • Keep shower doors or screens open after use
  • Maintain consistent background heating in winter
  • Avoid venting fans into roof spaces
  • Keep windowsills and grout clean to prevent mould spores spreading

Key Takeaway

Bathrooms that never fully dry are almost always a ventilation problem. Moisture from showers must be removed quickly and consistently, or it will linger and lead to mould, damage, and unhealthy indoor air.

High-quality bathroom exhaust fans remove moisture at the source, while Heat Recovery Ventilation (HRV/ERV) systems provide continuous extraction across all wet areas. Together, these approaches ensure bathrooms dry properly and stay healthier long term.