The pre-winter damp and drainage check

Autumn is when you prepare a house to be closed up and rained on for several months. Almost everything that goes wrong over an Australian winter — water getting in, water not getting away, and moisture that cannot escape once the windows shut — is cheaper to prevent in April than to discover in July.

Three checks, one for each turn of the year. Autumn — before winter, which is this one. Late winter — after the wet. Spring — before summer. If it is not the season you are in, go to whichever comes next.

This is the opposite job to the end-of-winter check. That one assesses what winter did. This one is about making sure it does as little as possible.

The two overlap on gutters, and the distinction is worth understanding: in autumn you are clearing leaf fall so water can get away all winter. At the end of winter you are looking for damage. Same ladder, different job.

Clear the gutters — but wait for the leaves to finish

The most common mistake with this job is doing it too early. Clearing gutters in March, while the trees are still dropping, means doing it again in June when you least want to.

Wait until the leaf fall is genuinely over, then clear properly:

• Everything out, including the sludge. Loose leaves come out easily; the composted layer underneath holds water against the metal and is what actually causes corrosion.
• Check the falls. Water sitting in a cleared gutter means it has sagged or was never set right. Standing water through a wet winter is how gutters fail from the inside.
• Flush the downpipes. A hose at volume, not a trickle. If it backs up, the blockage is in the downpipe or the stormwater line below it.
• Look behind the gutter. Where the roof edge meets the gutter, water should not be able to track backwards into the fascia. This is a slow, hidden failure that shows up years later as rotted timber.

Get the water away from the house

Once it is off the roof, the question is where it goes. Winter is months of it, so anything marginal will show.

Follow every downpipe to its outlet. Discharging at the base of a wall is not drainage — it delivers water straight to the footing and the subfloor.

Check the ground falls away from the building on every side. Garden beds, mulch and paving that have crept up over the years are the usual culprits, and soil above the damp-proof course lets moisture bypass it entirely — see what efflorescence on brickwork is telling you.

Clear surface drains, grates and pits of the same leaf fall you just took out of the gutters.

Check the subfloor vents are clear and sitting above the adjacent ground level. A subfloor that cannot breathe through a wet winter is where timber decay and termite conditions begin.

Fix the roof while it is still dry

Roof work in winter is slower, more dangerous and more expensive, and the leak you find in July has to be fixed in the weather that revealed it.

Flashings first. Where the roof meets a wall, a chimney, a skylight or a vent. Most leaks are flashing failures rather than roof-covering failures.

Ridge capping on tiled roofs — cracked or missing mortar at the highest point on the roof.

Cracked or slipped tiles, and on metal roofs, backed-out fasteners and perished washers.

Valleys, which carry the most water and collect the most debris.

If your roof only leaks in heavy or wind-driven rain, autumn is the time to chase it — see why your roof only leaks in heavy rain or wind.

Get ready for condensation season

This is the section most seasonal checklists leave out, and for a lot of Australian houses it is the one that matters most.

Winter mould is not caused by winter. It is caused by a house being closed up while the same amount of moisture keeps being generated inside it, meeting surfaces that have gone cold. By the time you can see it, it has been forming for weeks.

Check where your exhaust fans discharge. Ten minutes with a torch. If they terminate in the roof cavity rather than outside, you are storing every shower above your ceiling all winter — see where does your bathroom exhaust fan actually vent.

Test that the fans actually move air. Hold a tissue to the grille. Then consider a timer, because most of the moisture leaves a bathroom after the water stops.

Check the rangehood the same way. Recirculating units filter grease and return the moisture to the kitchen.

Look at the insulation coverage in the roof space, particularly the gaps at the perimeter where the ceiling meets the external wall. Those are the coldest strips of your ceiling and where the dark lines appear — see what dark marks on your ceiling mean.

Move furniture off external walls before winter, and open up wardrobes on external walls occasionally. Both are where mould appears first.

Decide now where the washing will dry. A single load dried indoors releases litres of water into the house, and doing it all winter in a closed-up house is the single most avoidable cause of mould. Full picture in winter condensation and mould.

Heating, before you need it

The same logic as air conditioning in spring — the worst time to find out it does not work is the first genuinely cold night.

• Run the system in heating mode long enough to know it works, and clean or replace the filters.
• Have flued appliances serviced. Gas heaters and wood heaters need their flues checked, and this is a carbon monoxide question rather than an efficiency one. Use a licensed gasfitter for anything gas, and follow your state's requirements on servicing intervals.
• Unflued gas heaters release both combustion products and water vapour directly into the room. If you use one, it will be the largest moisture source in the house all winter, and it needs adequate ventilation.
• Check the ceiling fan direction. Reversible fans should push air upward in winter to move warm air off the ceiling rather than blowing it at you.
• Sweep the chimney if you have an open fire or a wood heater, before the first use rather than after.

The last window for external coatings

Autumn is the final settled stretch for outdoor work, and a coating applied to damp timber in late May will fail.

Check external timber with the water test — if it soaks in rather than beading, the coating has gone and the timber is taking weather directly. Decks, posts, pergolas, window joinery and fence rails all matter, and end grain and post bases matter most.

If it is already too wet or too cold to coat properly, note it and do it in early spring instead. A coating applied badly is worse than one applied late.

The ground, and what it is about to do

Summer dries reactive clay and shrinks it. Winter rehydrates it and swells it back. Both directions move the house, and the winter version is the one that closes cracks and frees up doors that were binding in February — see cracks and sticking doors on reactive clay.

The useful thing to do now is record where things are before the ground rehydrates. Photograph any cracks you are watching, note which doors are binding, and date it. A record taken at the dry end of the cycle and compared at the wet end tells you more than any single inspection.

What is worth doing now versus later

Do now: gutters and downpipes once the leaf fall has finished, drainage and ground levels, flashings and ridge capping, exhaust fan checks, heating and flue servicing, and external coatings while the weather holds.

Can wait, but plan for it: gutter replacement, roof restoration, insulation upgrades and drainage works. All are better quoted properly and scheduled for spring than rushed in the first week of June.

A note on safety

Autumn roofs are slippery well before it looks wet — dew, moss and leaf residue all reduce grip, and morning frost in cooler regions makes a tiled roof genuinely hazardous. Falls from ladders and roofs remain a leading cause of serious injury in home maintenance.

Inspecting from a stable ladder is one thing. Walking a wet, steep or brittle roof is another, and it is worth paying someone with the right equipment rather than doing it yourself in shorter daylight.

Where to go next

Between them, the three seasonal checks cover most of what an Australian house asks of its owner each year.

Read next: winter condensation and mould, which is the problem this whole exercise is trying to get ahead of, or the pre-summer heat and storm check if summer is closer than winter where you are.

An afternoon in April is worth a great deal more than the same afternoon in July.