Ventilation, mould and indoor air quality

A damp, musty house isn’t a cleaning problem – it’s a moisture problem. Find out where the moisture is coming from, then deal with the cause, not just the marks on the wall.

Find local installers See the 5 upgrades

A common sign

“There’s mould on the bedroom wall again, and the house smells musty.”

If that sounds familiar, moisture is building up faster than your house can get rid of it. Wiping it off treats the symptom. Ventilation deals with the cause.

About Ventilation, mould and indoor air quality

Fresh air, without the heat loss.

Ventilation specialists move damp air out of the house and fresh air in. Sub floor fans dry out the space under the floor. Heat recovery systems swap stale air for fresh while holding on to much of the warmth. Damp specialists treat moisture rising up through the walls.

This matters more as homes get sealed up. Insulation and draught sealing keep heat in – and moisture too. A well sealed house needs a planned way to breathe.

Helps with

Mould on walls, ceilings and in wardrobes

Helps with

A musty smell from under the floor

Helps with

Condensation on the windows every morning

Worth knowing

There is no government rebate for ventilation or mould work anywhere in Australia. Be wary of any quote that says otherwise.

Not sure where the damp is coming from?

Where it shows up points to the cause.

Look at where the damp appears and when. That usually tells you who to call.

Help me work out the cause

Musty smell from under the floorSub floor ventilation Tide marks low on the wallsRising damp treatment Mould that keeps coming backMould removal and treatment Stuffy since the house was sealedHeat recovery ventilation Not sure what you’re dealing with?Indoor air quality testing Can’t find where it starts?Get a home energy assessment

5 upgrades in this category

Choose the upgrade you need.

A sunlit open-plan living room with two round fresh-air vents in the ceiling, a cream sofa and timber coffee table, and floor-to-ceiling glass looking onto a native garden.

Heat recovery ventilation

Brings fresh air in without throwing the heat out with the stale air. What a tightly sealed house needs.

Find specialists

A technician with a head torch fitting ducting under the floor of a modern sandstone and timber home at dusk, a louvred vent and fan controller on the wall beside the open sub floor hatch.

Sub floor ventilation

Fans and vents that dry out the space under the floor, which is where a musty smell upstairs usually starts.

Find specialists

A technician in a white coverall and respirator on a ladder testing a mould patch around a bathroom ceiling exhaust fan, a thermal image on the tablet beside her.

Mould removal and treatment

Treating the growth and finding what is feeding it. Cleaning it off without fixing the moisture just delays it.

Find specialists

A technician in dark workwear and safety glasses kneeling on a garden path, injecting damp proof cream into a row of holes drilled low along the weathered base of an old red brick house wall.

Rising damp treatment

Moisture drawn up through the brickwork, showing as tide marks and bubbling paint near the floor.

Find specialists

A consultant in an olive polo checking a bedroom wall with a moisture meter, an air quality monitor on a tripod beside her.

Indoor air quality testing

Measures humidity, moisture and spore levels so the work is aimed at something rather than guessed at.

Find specialists

Not sure where to start?

Stop guessing, start saving: find your home’s energy score.

Don’t waste money on upgrades you don’t need. A professional home energy assessment shows where your house loses heat and power, so your budget goes where it makes the biggest difference.

Find an assessor near me

Sub floor ventilation and damp specialists

Find sub floor ventilation and damp specialists near you.

A few of the 65 listed across Australia

A rammed earth home with a planted green roof and solar panels among ferns and tall trees.

Waldron Heating Cooling & Hot Water

4.8 59 Google reviews

Ducted reverse cycle heating and coolingSplit system air conditioningSolar hot waterHeat recovery ventilationHeat pump hot water systems

Based in Delacombe

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A suburban home seen from the street, with rooftop solar.

Polarised Electrical Services

5.0 56 Google reviews

Rooftop solar installationHome battery installationHeat pump hot water systemsSplit system air conditioningDucted reverse cycle heating and coolingInduction cooktop installationSwitchboard upgradesHome EV charger installationSub floor ventilationThermal imaging and insulation scans

Based in Boronia

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A low single storey modern home with timber battens, full height glazing and solar panels on a flat roof.

Air Vegas Electrical & Air Conditioning

5.0 98 Google reviews

Split system air conditioningDucted reverse cycle heating and coolingSwitchboard upgradesSub floor ventilationLED lighting upgradesSmart lighting controls

Based in Malvern East

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A two storey contemporary home with pale render, charcoal cladding and solar panels on a skillion roof.

Precision Plumbing Heating and Cooling

4.8 49 Google reviews

Split system air conditioningDucted reverse cycle heating and coolingAir conditioning servicingHeat pump hot water systemsHeat recovery ventilationHydronic heating

Based in Breakwater

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A long, low rural home at dusk with solar panels on its metal roof and gum trees behind.

Ecocraft Pty Ltd

5.0 11 Google reviews

Window and door replacementuPVC double glazed windowsDraught and weather sealingCeiling and roof insulationUnderfloor insulationWall insulationHome energy assessments and auditsHeat recovery ventilationRetrofit double glazing

Based in Hurstbridge

View business

Before you choose an installer

See our guides on ventilation and damp.

All guides

Ventilation You sealed the house. Now it's damp. Why a tighter house grows condensation and mould, what ventilation actually fixes it, and the order that avoids the problem in the first place.

Insulation Where the heat actually leaves your house Ceiling, walls, floor, windows and gaps, in the order they matter, and what each one is worth in a typical brick veneer home.

Start here The right order to upgrade your home Insulation before heat pump sizing, sealing before ventilation, and solar later than you would think. The dependencies nobody explains before you are quoted.

Related goal

Ventilation is the other half of a sealed house.

If your real goal is a healthier home, ventilation and sealing work together. See the upgrades worth considering – and the order that keeps the moisture out.

Improve mould and ventilation See the whole-home upgrade order