Subfloor humidity
82%→55%
Sydney’s subfloor and underfloor ventilation specialists. We clear rising damp, mould and that musty under-floor smell from homes right across Sydney — quietly, cleanly, and backed by a 5-year manufacturer & installation warranty. Servicing the North Shore, Northern Beaches, Inner West & Sutherland Shire.
If you’re looking for subfloor ventilation in Sydney, you’re in the right place. We design and install subfloor and underfloor ventilation systems that draw damp, stale air out from under your home and pull fresh, dry air in — the proven fix for rising damp, subfloor mould and that musty smell in older Sydney homes.
From quiet subfloor fans to fully ducted systems, we match the right setup to your home and install it in a day. Whether it’s a Federation home on the North Shore, a terrace in the Inner West or a brick-and-tile in the Shire, the cause is the same — too little airflow under the floor. Good sub floor ventilation gets the air moving again, so the ground dries out and stays dry.
Have a play with the toggle — here's what's going on under a Sydney floor, in plain English.
Old air vents get painted over and the air under your floor stops moving. Damp from the ground just sits there, soaks into the floorboards and creeps up your walls — that's the musty smell, the peeling paint and the black mould you can see inside.
Quiet fans gently pull fresh, dry air right through the subfloor on a timer. The ground dries out, the damp has nowhere to sit, and your floors and walls stay dry — so the smell clears and the mould stops coming back.
The right system depends on your subfloor's size, access and how blocked the airflow is. As your local Sydney subfloor and underfloor ventilation team, we assess on-site and fit the right one — here's the range.
Brick or wall vents let air cross the subfloor on its own. Silent and free to run — but only enough by itself for well-exposed homes with mild damp.
A quiet mechanical fan on a timer pulls stale, damp air out and draws fresh air in through the vents — the reliable fix for most Sydney subfloors.
Fans on both sides — one pushing dry air in, one drawing damp air out — for a forced cross-flow that reaches every corner.
We fit the German-made Blauberg Turbo range — quiet, 2-speed mixed-flow fans. On a timer they only run about 8 hours a day, so the running cost is tiny. Slide to your own power rate and run time:
Figures use the Blauberg Turbo 2-speed power draw (low–high speed), running 8 hours a day, 365 days a year, at the rate you set above. NSW residential usage rates averaged roughly 28–35c/kWh in 2026 — so even the biggest fan runs for about the price of a coffee a fortnight, on par with a bathroom exhaust fan. Your real figure depends on fan size, speed setting and your power plan.
The Sydney is full of beautiful period homes — and period homes are exactly where rising damp and subfloor mould love to live. We've spent years fixing these problems across the area, from Federation terraces to post-war semis.
Much of the Sydney sits on heavy clay soils that hold water long after rain, and the tightly-packed terraces and semis of Newtown, Chatswood and Balmain were built with very little airflow under the floor. Add original brick piers, low subfloor clearance and decades of paint over the air vents, and the air underneath simply stops moving — the perfect setup for rising damp and mould.
That "old house" smell that hits when you walk in — it's coming up through the floor.
Black spotting low on internal walls, in wardrobes and behind furniture.
Timber boards lifting at the edges or bouncing underfoot as moisture swells them.
Foggy windows and a clammy feeling indoors, worst through the cooler months.
Soft, decaying joists and bearers — the structural cost of years of trapped damp.
Mould spores from below circulate upstairs, flaring hay-fever and breathing issues.
A balanced system gently draws fresh, drier air in one side and pushes humid air out the other, cycling the whole subfloor several times an hour.
We pop over, log the humidity and airflow, and check your access — no pressure, no jargon.
Quiet fans pull cool, drier outside air into the dampest spots under your floor.
Stale, moist air is moved across and out the other side — no soggy dead pockets left.
Set once and forget it — it runs through the day, switches off overnight, and you'll never hear it.
We install across the North Shore, Northern Beaches, Inner West and Sutherland Shire — and right across greater Sydney in between, from Western Sydney to the Blue Mountains and the Central Coast.
Chatswood, Mosman, Gordon, St Ives, Lane Cove & more
View North Shore →Manly, Dee Why, Avalon, Mona Vale & more
View Northern Beaches →Balmain, Marrickville, Leichhardt, Drummoyne & more
View Inner West →Cronulla, Miranda, Caringbah, Sutherland & more
Now servicingYes — most Sydney terraces have tight access, and we size the fans and ducting specifically for low-clearance subfloors. We assess access on the day and design around it.
Not at all. The fans are designed for continuous, near-silent running — most people can't tell it's on. It sits entirely under the floor, out of sight.
Most homes are finished in a single day. We'll confirm timing after the on-site assessment, once we've seen the access and layout.
Ventilation removes the moisture that mould and musty odours feed on. Once the subfloor dries out and stays dry, the conditions that cause them are gone.
Very little. The fans draw minimal power and run on a timed cycle through the day only, so the running cost is tiny.
Subfloor ventilation in Sydney starts from around $900, with the final price depending on the size of your home, the subfloor access and how many fans it needs. We give you a fixed, no-obligation quote after a free on-site assessment, so you know the exact cost up front — no surprises.
Nothing, really — they’re two names for the same thing. The space under a suspended timber floor is called the subfloor or underfloor, and both terms describe getting fresh air moving through it to control moisture and damp.
Passive vents help, but most Sydney homes — especially terraces, semis and homes close to the ground or on clay — don’t get enough natural airflow. Mechanical subfloor fans move a guaranteed volume of air, which is why they fix damp problems that extra passive vents can’t.
Right across Sydney. Our main service areas are the North Shore, Northern Beaches, Inner West and Sutherland Shire, plus most suburbs in between. Not sure if we reach you? Just give us a call.
We'll measure the moisture, check your access and give you a friendly, fixed quote — no pressure, no obligation. Call now or send your details and a real local will get back to you.