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If your Adelaide home has a subfloor (crawl space under the house), its ventilation is one of the biggest factors in your mould risk. Many older Adelaide homes have inadequate or blocked subfloor ventilation — leading to mould in the subfloor that affects the entire house.

Types of Subfloor Ventilation

Passive ventilation ($500–$1,500): Wall vents that allow natural cross-ventilation. Works well when unobstructed and the subfloor has good clearance. Many Adelaide homes have had vents blocked by garden beds, paths, or renovations.

Mechanical fans ($1,500–$3,000): Electric fans that force air through the subfloor. Ideal for homes with limited natural airflow — common in Mitcham, Tea Tree Gully, and the Hills where sloping blocks restrict air movement.

Ducted systems ($3,000–$5,000): Fan-forced air ducted to specific problem areas. Best for large subfloors or homes with obstructed airflow paths.

When You Need Subfloor Ventilation

• Musty smell from under the house
• High moisture readings on ground-floor walls
• Visible mould on subfloor timbers or bearers
• Rising damp symptoms on lower walls
• Reactive clay soil that stays damp year-round

Full subfloor ventilation guide. A professional assessment measures actual subfloor humidity and recommends the right system. Get connected with qualified installers. View all costs.

A properly sized exhaust fan is the single most effective weapon against bathroom mould. But most Adelaide homes have fans that are undersized, poorly ducted, or not ducted externally at all. Here’s how to get it right.

How to Size Your Exhaust Fan

Australian Standard AS 1668.2 recommends a minimum of 25 litres per second (L/s) — approximately 50 CFM — for a standard bathroom. For ensuites or bathrooms without windows, increase to 40 L/s (80 CFM).

Ducting Matters More Than the Fan

A powerful fan ducted into the roof cavity just moves moisture from your bathroom into your roof space — creating mould there instead. The duct MUST go to an external wall or roof vent. Use rigid ducting (not flex) for maximum airflow.

Common Adelaide Mistakes

• Fan ducted into roof cavity (creates roof mould)
• Fan too small for the room (decorative, not functional)
• Fan only runs while light is on (needs a run-on timer for 15 minutes)
• Flexible duct kinked or compressed (reduces airflow 50%+)

Recommended Setup

Inline centrifugal fan (150mm), rigid ducting to external vent, run-on timer (15-20 minutes after light off), humidity sensor switch (runs automatically above 65% RH). Total cost installed: $400-$800.

For existing mould that a fan upgrade won’t fix, professional assessment ensures the moisture source is fully addressed. Get your free quote.

Adelaide’s mould season runs May–September. Preparing your home before winter dramatically reduces the chance of mould taking hold. Use this checklist to get ahead of the problem.

Before Winter Checklist

• ☐ Check all exhaust fans are working in bathrooms and kitchen
• ☐ Clear gutters and downpipes of leaf debris
• ☐ Check subfloor vents are unblocked
• ☐ Inspect roof for potential leak points
• ☐ Move wardrobes and furniture 50mm from external walls
• ☐ Check window seals and weatherstripping
• ☐ Service heating systems (ducted and HVAC)
• ☐ Buy a hygrometer ($15-$30) to monitor humidity
• ☐ Ensure you have a plan for drying clothes (NOT indoors without ventilation)
• ☐ Clear garden vegetation from house walls for airflow

During Winter Habits

• Run exhaust fans 15 minutes after showering/cooking
• Open windows briefly each morning for air exchange
• Target indoor humidity below 60%
• Wipe condensation from windows promptly

If mould appeared last winter, get a pre-winter inspection to fix the cause before it happens again. Take our risk assessment and get connected with specialists.

Owning a heritage home in Burnside, Norwood, or Unley means balancing preservation with liveability. Rising damp and mould are endemic in these beautiful old buildings — but fixing them doesn’t have to compromise their character.

Heritage Constraints

Heritage-listed properties have restrictions on external modifications. You can’t necessarily add modern ventilation systems visibly, alter window openings, or change the building envelope. This makes mould management more challenging — but not impossible.

Heritage-Compatible Solutions

• Chemical DPC injection: Invisible from outside, addresses rising damp without physical alterations
• Lime render (not cement): Breathable plaster that manages moisture in stone walls naturally
• Discreet ventilation: Sub-floor vents, heritage-style wall vents, concealed mechanical ventilation
• Secondary glazing: Interior glass panel additions that don’t alter heritage windows

A specialist who understands heritage buildings can recommend solutions that satisfy both heritage requirements and mould remediation needs. View typical costs and get connected with experienced specialists.

If your Adelaide home was built between 1950 and 1975, it has a specific set of construction characteristics that make mould almost inevitable without intervention. These homes dominate suburbs like Charles Sturt, West Torrens, Marion, and Salisbury.

The Problem with Post-War Construction

• No insulation: Cavity brick walls with no insulation create extreme cold bridging
• Single glazing: Windows drip with condensation every winter morning
• Minimal ventilation: Small windows, no exhaust fans, sealed-up wall vents
• Concrete slab on ground: No subfloor ventilation, moisture wicks through the slab

The Mould Hotspots

South-facing bedroom walls (behind wardrobes), original bathrooms without exhaust fans, ceiling corners where cold roof meets warm interior.

What to Prioritise

Install bathroom exhaust fans ($200-$500), add wall insulation during any renovation ($2,000-$5,000), consider secondary glazing ($200-$400/window). These three changes dramatically reduce mould risk. Professional inspection identifies your home’s specific vulnerabilities. Get your free assessment.

Adelaide’s coastal suburbs — Glenelg, Brighton, Henley Beach, Somerton Park — have a mould factor that inland suburbs don’t: persistent salt-laden humidity from the Gulf St Vincent.

How Coastal Air Creates Mould

Onshore breezes carry moisture and salt inland daily. This humidity is higher and more sustained than inland areas. Salt deposits on surfaces attract and hold moisture (salt is hygroscopic). The combination accelerates condensation on cold surfaces and provides sustained dampness for mould growth.

Most Affected Areas in Coastal Homes

• Bathrooms (already humid + coastal moisture)
• Ceiling mould in poorly ventilated rooms
• Window frames and sills facing the coast
• South-facing external walls that never dry out

Coastal Prevention Strategies

Ensure all rooms have adequate ventilation — coastal humidity makes it even more critical. Clean salt deposits from window frames regularly. Use a dehumidifier during humid weather. Maintain good subfloor ventilation — coastal ground moisture is higher than inland. Get connected with coastal-experienced specialists.

Living in the Adelaide Hills means beautiful scenery, cooler temperatures, and significantly more mould risk than the Adelaide plains. Here’s why Hills properties face unique challenges.

The Hills Microclimate

The Adelaide Hills receive 700-1000mm of annual rainfall compared to 500-600mm on the plains. Winter fog, higher humidity, and cooler temperatures create extended periods of moisture on building surfaces. The dense tree canopy in suburbs like Stirling, Crafers, and Aldgate further restricts airflow and sunlight.

Common Mould Issues

• Subfloor mould: Sloping blocks trap moisture under homes. Ventilation systems are essential.
• External wall mould: Shaded walls stay damp for extended periods.
• Roof cavity mould: Temperature differentials cause condensation in roof spaces.
• Rising damp: Older stone and timber homes without damp-proof courses.

Hills-Specific Solutions

Mechanical subfloor ventilation is often mandatory in Hills properties. Gutter maintenance is critical with heavy leaf fall. Regular professional inspections catch problems before they become severe. Get matched with Hills-experienced specialists.

Not all Adelaide suburbs are equal when it comes to mould risk. Geography, housing age, soil type, and microclimate all play a role. Here are the suburbs where we see the most mould enquiries — and why.

Highest-Risk Suburbs

Adelaide Hills: 30% more rainfall, dense vegetation, subfloor moisture on slopes, older homes with limited ventilation.

Burnside: Heritage stone homes with rising damp, heavy tree canopy reducing airflow, older housing stock.

Mitcham: Foothills location with higher humidity, reactive clay soils retaining moisture, mix of older and newer homes.

Holdfast Bay: Coastal humidity and salt air moisture, older beachside homes with poor ventilation.

Norwood and Prospect: Character homes with minimal ventilation, cold stone/brick walls, heritage restrictions on modifications.

Moderate-Risk Suburbs

Charles Sturt and West Torrens: 1950s-70s brick homes with poor insulation. Marion: Mix of housing ages with condensation issues in older stock. Salisbury and Tea Tree Gully: Newer developments have less mould but established areas face subfloor issues.

Assess your home’s specific risk and get connected with local specialists.

When your landlord won’t fix a mould problem, SACAT (South Australian Civil and Administrative Tribunal) is your next step. Here’s what the process looks like from start to finish.

Before You Apply

SACAT expects you to have attempted resolution directly with your landlord first. You need: written notice to the landlord, reasonable time allowed (14 days minimum), and evidence the problem persists. A professional mould report significantly strengthens your application.

The SACAT Process

1. Application: Lodge online or in person. Fee is approximately $80.
2. Conciliation: SACAT attempts mediation between you and the landlord first.
3. Hearing: If conciliation fails, a tribunal member hears both sides and reviews evidence.
4. Order: SACAT can order repairs, rent reduction, compensation, or lease termination.

What Evidence Helps

• Air quality test results showing unsafe spore levels
• Professional inspection report identifying structural causes
• Medical certificates linking health symptoms to mould
• Timestamped photos of mould progression
• Written correspondence with landlord

Full tenant rights guide. Get professional documentation before your hearing.

Your rental has severe mould, your landlord won’t fix it, and you’re worried about your family’s health. Can you break your lease without penalty?

The Short Answer

Yes — but only through the proper legal process. You cannot simply walk away from a lease because of mould. You need to apply to SACAT (South Australian Civil and Administrative Tribunal) for an order terminating the lease.

The Legal Process

1. Report the mould in writing to your landlord (keep evidence)
2. Allow reasonable time for repair (typically 14 days)
3. If landlord fails to act, contact SA Consumer & Business Services for advice
4. Get a professional mould inspection report documenting the issue
5. Apply to SACAT for a hearing
6. SACAT may order repairs, rent reduction, or lease termination

What Strengthens Your Case

Medical evidence linking symptoms to mould exposure. Professional air quality testing showing elevated spore levels. Written evidence of landlord being notified. Photos documenting mould over time. Evidence that the cause is structural (rising damp, leaks) not lifestyle.

Complete tenant rights guide. Get professional evidence to support your case.