The Mould Crisis in Australian Rentals: Who's Responsible?

The Scale of the Problem

Mould affects an estimated 1 in 3 rental properties across Australia. In humid coastal cities like Sydney, Brisbane, and Melbourne, the numbers are even higher. For renters, it's more than an inconvenience — mould exposure is linked to respiratory problems, allergies, and worsened asthma.

But who's actually responsible? The answer isn't always clear, and that's where disputes begin.

Landlord vs Tenant Responsibilities

Landlords are responsible for: - Structural causes of mould — roof leaks, rising damp, faulty plumbing - Adequate ventilation — working exhaust fans in bathrooms and kitchens - Maintaining the property in a reasonable state of repair - Fixing damp issues reported by tenants in a timely manner

Tenants are responsible for: - Lifestyle moisture — using exhaust fans, opening windows for ventilation - Not drying clothes indoors without adequate airflow - Reporting damp or mould to the landlord promptly - Keeping the property reasonably clean

The Grey Area

The problem is proving cause. Was the mould caused by a hidden leak (landlord's responsibility) or by the tenant not using the exhaust fan (tenant's responsibility)? Without evidence, it becomes a blame game.

How a Health Certificate Helps

A PropLedger Report assesses the property's ventilation, moisture risk, and building condition independently. It identifies: - Whether exhaust fans are present and adequate - The property's natural ventilation capacity - Humidity risk based on climate and building type - Structural factors that increase mould risk

This gives both parties objective, evidence-based information. If the certificate flags "no exhaust fan in bathroom" — that's clearly a landlord issue. If the ventilation is adequate but mould persists, the conversation shifts to tenant behaviour.

What Renters Can Do Today

1. Before signing a lease, ask if the property has a health certificate
2. Document existing mould with photos and dates when you move in
3. Report issues promptly in writing to your landlord or agent
4. Check ventilation — does every wet area have a working exhaust fan?
5. Request a certificate — even asking sends a signal that you care about property health

At PropLedger, we believe transparency benefits everyone. Renters can view and download property health reports completely free. Because knowing what you're renting shouldn't cost extra.