Every winter we take the same calls. A homeowner in Surrey Hills notices the edges of their Baltic pine boards have lifted slightly and the floor feels ribbed underfoot. Someone in Brighton has gaps between boards wide enough to lose a coin in. A Hawthorn client is convinced their floor is ruined and wants it sanded immediately.
In most of those cases the floor is not ruined. It is doing what timber does. And in a meaningful number of them, sanding immediately would be the single most expensive mistake available.
Iconic Flooring has been refinishing Melbourne timber floors from our base on Warrigal Rd in Oakleigh since 2012 — across the eastern suburbs, Bayside, and the Mornington Peninsula. This guide explains what winter actually does to a timber floor here, how to read what yours is telling you, and how to decide whether to book work now or wait.
Timber Never Stops Moving
Timber is hygroscopic — it absorbs and releases moisture until it reaches equilibrium with the air around it. Take on moisture and boards swell across their width; lose it and they shrink. This never stops, not in a hundred-year-old floor, not in one laid last year.
What matters is that the movement is even and within a normal range. Problems arise when one face of a board is at a very different moisture content from the other, or when conditions swing hard and fast. That imbalance is exactly what Melbourne’s winter tends to create.
The Australian Timber Flooring Association publishes guidance on acceptable in-service moisture ranges, and a competent installer or refinisher will take meter readings rather than eyeballing it. If someone quotes you to sand a moving floor without measuring anything, that is worth noticing.
Melbourne’s Winter Problem Is Damp, Not Cold
Our winters are mild by world standards. That is not the issue. The issue is that from roughly June through September, Melbourne floors get squeezed from both directions at once.
Wet ground underneath
Most of Melbourne’s period housing stock — the Edwardians in Surrey Hills and Camberwell, the Federation homes in Balwyn and Hawthorn, the Victorian terraces in Richmond and Fitzroy — sits on a suspended timber floor over a subfloor void. That void is designed to be ventilated and to stay dry.
Over a century, things happen to it. Garden beds get built up against the external walls and cover the vents. A concrete path or paving gets laid over them. A deck goes on and blocks airflow. Downpipes discharge next to the footings. Landscaping changes which way water runs. Meanwhile the winter rain keeps coming.
The result is a damp, poorly ventilated space under a floor whose upper surface is sealed with polyurethane. Moisture can only really move one way — up through the underside of the boards.
Dry air on top
At the same time, ducted and reverse-cycle heating runs for months and pulls indoor humidity down considerably. So the top of the board is drying while the bottom is taking on moisture — the exact imbalance that causes trouble.
Coastal air on the bay and the Peninsula
Homes in Black Rock, Sandringham, Hampton, Brighton, and down through Mount Eliza, Mornington and Mount Martha sit in consistently higher ambient humidity. Holiday and weekender properties add another factor: a house closed up and unheated for weeks behaves very differently from one lived in daily. Floors in those homes often need a finish system chosen with that in mind.
Reading Your Floor: Four Things You Might Be Seeing
Cupping — edges higher than the centre
Run your hand across the boards. If each one feels like a shallow trough, with the long edges raised and the middle lower, that is cupping. It means the underside of the board is wetter than the top, so the bottom face has swollen.
Cupping is a symptom, not a disease. Something is putting moisture under your floor: subfloor damp, blocked vents, a slow plumbing leak, a dishwasher or fridge that has been weeping quietly, or a bathroom membrane that has failed. Find the cause first.
Crowning — centre higher than the edges
The inverse profile, and usually a self-inflicted one. Crowning most often appears when a cupped floor was sanded flat while still cupped. The raised edges were machined off; then the floor dried out and returned toward flat, leaving the centre proud and the board thinner at the edges than it should be. It is very difficult to correct properly, and it costs you wear layer you cannot get back.
Gapping — spaces opening between boards
Boards shrink across their width as they dry, and months of heating will do that. Gapping is the most common winter complaint and, in a solid timber floor, frequently the least alarming — many floors gap in winter and close up again over summer. Wider boards show it more than narrow ones, simply because there is more width to shrink.
The useful test is whether it is seasonal. If gaps appear each winter and close each summer, that is normal movement. If they keep widening year on year and never close, something else is going on and filling them is not the answer.
Peaking or lifting
Boards pressing hard against each other, lifting at the joins, or in bad cases coming away from the subfloor. This means the floor has expanded with nowhere to go — usually insufficient expansion allowance at the perimeter, or a significant moisture event. This one is not a wait-and-see situation; get it looked at.
The Mistake That Costs the Most
If you take one thing from this article, take this: do not sand a cupped floor until the moisture problem is fixed and the floor has stabilised.
It is tempting. A cupped floor looks bad, sanding makes it flat, and the result on the day looks excellent. But you have machined material off the high edges of a board that was temporarily distorted. When the moisture source is dealt with and the board returns to its natural shape, it does not return to flat — it goes past flat into crowning, and it is now permanently thinner at the edges.
A solid hardwood floor can typically be sanded three to five times over its life depending on board thickness above the tongue; engineered timber usually once or twice. Spending one of those on a floor that was going to change shape anyway is a genuine waste of a finite resource.
The correct sequence is always: find the moisture source, fix it, let the floor dry and stabilise, measure, then sand. Depending on severity that wait can be weeks or months. We would rather tell you that at the quote than take the job today.
So — Should You Sand in Winter?
The honest answer is that winter is a perfectly good time to refinish a Melbourne timber floor, with two conditions and one genuine advantage.
Condition one: the floor must be stable. If it is actively cupping, the cause has to be resolved first. This has nothing to do with the season and everything to do with the floor.
Condition two: conditions during application and cure must be controlled. Finish manufacturers specify minimum ambient and substrate temperatures and acceptable humidity ranges for their systems. In a cold, closed-up house those numbers can be missed, and coatings applied outside specification can cure poorly, stay soft, or fail early. Managing this properly is part of the job — it is not a reason to avoid winter, but it is a reason to use someone who accounts for it.
The advantage: your floor will be at its narrowest. Because winter is when boards have shrunk, gaps are at their widest. A floor coated in winter has finish reaching down into those open gaps. As boards expand through summer, the gaps close — rather than the reverse situation, where a floor coated in humid conditions opens up later and reveals raw, unfinished board edges. There is a reasonable argument that late winter is a sensible time to do this work in Melbourne.
Scheduling is also easier. Spring and early summer are when everyone wants their floors done before Christmas, and lead times stretch accordingly.
What Actually Differs About a Winter Job
- Cure times can extend. Water-based polyurethanes cure more slowly in cold conditions with low air movement. Our standard guidance is walkable in socks after around 24 hours and furniture back after about 72 — in winter, allow a little more and do not rush the furniture.
- Ventilation needs managing, not maximising. Throwing every window open in July drops the temperature below what the coating needs. The answer is controlled airflow and gentle background heat, not a gale.
- Dust and drying underfoot. Wet shoes and muddy access matter more in winter. We manage protection and access as part of the job.
- Dustless sanding is more valuable when the house is shut up. With windows closed for months, containing dust at source matters more. Our Bona FlexiSand system with HEPA extraction captures roughly 99.8% of dust at the machine, and most clients in occupied homes choose it.
Before You Book: A Short Checklist
- Check your subfloor vents. Walk the perimeter of the house. Are the vents clear, or buried behind garden beds, paving, decking or rendered over? This is the single most common cause of subfloor damp in Melbourne period homes and it is often cheap to fix.
- Look for water sources. Under the dishwasher, behind the fridge, around the base of showers, at downpipes and where they discharge.
- Photograph the floor now. If you are unsure whether movement is seasonal, dated photos of the same spot across the year settle the question.
- Note whether it is getting worse. Stable-but-imperfect is a very different conversation from actively deteriorating.
- Do not fill gaps yourself. Filling a floor at its winter widest locks in material that has nowhere to go when boards expand in summer. Gap filling has its place, but it is a decision to make with the season in mind.
When It Isn’t a Flooring Job at All
Sometimes the right advice is that you do not need us yet. Persistent subfloor damp, rising damp, drainage that directs water at the footings, a failed bathroom waterproofing membrane, or a plumbing leak are all building problems, and refinishing over them just resets the clock until the same damage reappears.
Where that is what we find at the site assessment, we will say so plainly and tell you what needs to happen first. We would rather refinish your floor once, properly, in six months than twice in three years.
Frequently Asked Questions
My floorboards have gaps every winter. Is something wrong?
Usually not. Seasonal gapping that appears in winter and closes over summer is normal timber movement, particularly with wider boards. Gaps that widen year on year and never close are a different matter and worth investigating.
Can you sand out cupping?
Only once the moisture source has been resolved and the floor has stabilised — otherwise you get crowning and lose wear layer permanently. We measure moisture content at the assessment and advise honestly on whether the floor is ready.
How long does refinishing take in winter?
A standard three-bedroom Melbourne home of roughly 90–120m² is typically 3–4 working days: a day of sanding, then coats applied over following days. In cold conditions allow a little extra before returning furniture.
Should I just wait until summer?
If the floor is stable, there is no strong reason to wait, and there is a reasonable argument for coating while boards are at their narrowest. If the floor is actively cupping, waiting is not about the season — it is about fixing the moisture problem.
Will you tell me if my floor can’t be sanded again?
Yes. We measure the remaining wear layer at the site assessment. Solid hardwood generally allows three to five sands over its life; engineered timber one to two. If there isn’t enough material left, we’ll tell you rather than take the job.
Do you cover the Mornington Peninsula in winter?
Yes — we run regular Peninsula scheduling year-round, covering Mount Eliza, Mornington and Mount Martha alongside our eastern suburbs and Bayside work.
Not Sure What Your Floor Is Doing? Get It Looked At.
Cupped boards in a Camberwell Edwardian. Winter gaps in a Brighton hardwood floor. Damp under a Surrey Hills subfloor that has never been properly ventilated. A Peninsula holiday home that has sat closed up since Easter.
We’ll come and measure, tell you what is actually happening, and give you a written fixed-price quote — or tell you straight that the floor needs time and what to fix in the meantime. No phone estimates, because they are rarely accurate.
Call Iconic Flooring on 0473 837 777, or request a free on-site assessment.
Family-run from 97 Warrigal Rd, Oakleigh since 2012. Bona, Synteko and Loba certified. VBA registered, fully insured, and our own crew on every job — no subcontractors.
Learn more about timber floor refinishing, timber floor installation, and staircase renovation, or read our guide to how many times a timber floor can be sanded and what floor sanding costs in Melbourne.
