Mould Prevention in Rental Properties Tasmania: Landlord Responsibilities

Why Mould Is a Compliance Issue in Tasmania

Tasmania's cold, wet winters create ideal conditions for mould in rental properties. Window condensation, damp walls and black mould on ceilings aren't just cosmetic problems — they can trigger complaints under Part 3B of the Residential Tenancy Act 1997 if the underlying cause is a structural or maintenance failing the landlord should have addressed.

The legal question is always causation: is the mould driven by something the landlord controls (the building envelope) or something the tenant controls (how they use the property)?

When Mould Is the Landlord's Problem

Structural and maintenance causes fall squarely on the property owner:

• Rising damp from a defective or missing subfloor damp-proof course (s. 36I weatherproofing)
• Rain ingress through broken roof tiles, cracked flashing or rusted gutters (s. 36I)
• Failed mechanical ventilation — exhaust fans in windowless bathrooms or laundries that don't work or vent into the roof cavity instead of outside (s. 36O)
• Inadequate natural ventilation — habitable rooms with openable window area below the 5% floor area threshold (s. 36O)
• Missing or inadequate heating — no fixed heater in the main living area, or a heater that doesn't generate enough warmth for the room size (s. 36M)

If any of these factors is contributing to mould growth, the landlord has a repair obligation. A tenant can issue a Notice to Repair and escalate to the Residential Tenancy Commissioner if the defect isn't fixed within the statutory window.

When Mould Is the Tenant's Responsibility

Under Section 53, tenants must maintain reasonable cleanliness during the tenancy. Mould caused by occupant behaviour stays with the tenant:

• Drying laundry indoors without opening windows or running ventilation
• Not using installed exhaust fans during showers or cooking
• Blocking ventilation openings with furniture pushed against external walls
• Neglecting routine surface cleaning that allows mould to establish

The Problem: Proving Causation

Most mould disputes are messy because both factors overlap. A bathroom with a working exhaust fan can still grow mould if the fan is undersized for the room, or the ductwork terminates in the roof space rather than outside.

The research report is clear on this: landlords should never diagnose structural damp or toxic mould from photographs alone. When a dispute arises, commission an independent inspection by a licensed building surveyor or environmental health officer to establish the actual cause before allocating repair costs or lodging bond claims.

Practical Prevention Steps

Before a tenancy starts:

1. Check that every exhaust fan in bathrooms, toilets and laundries actually vents to external air (not into the roof cavity)
2. Verify openable window areas meet the 5% floor area ratio in all habitable rooms
3. Confirm the fixed heater in the main living area works and is adequate for the space
4. Inspect subfloor areas for signs of rising damp or inadequate drainage
5. Look for evidence of past leaks — staining on ceilings, peeling paint around window frames, musty smells in wardrobes

During a tenancy, use routine inspections (once every three months, 24 hours' written notice) to check for early signs of moisture problems. Catching condensation damage at the first inspection is far cheaper than dealing with an established mould complaint six months later.

What Happens When a Complaint Lands

A tenant who reports mould as a minimum standards breach triggers the repair clock. If the cause is structural (weatherproofing, ventilation or heating), it's a general repair with a 28-day deadline — or an urgent repair with a 24-hour deadline if it involves an essential service failure like a non-functional heater.

Fines for failing to meet minimum standards reach 50 penalty units, currently $10,650 per offence.

Our Rental Minimum Standards in Tasmania guide includes a mould and dampness inspection worksheet that walks through every structural checkpoint, plus the repair-clock tracking sheet so you stay within deadlines.

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