In South East Queensland, expect to reseal an inland driveway every few years, sooner on a coastal or full-sun surface, and later on a shaded slab with a penetrating sealer. Interval is driven by exposure rather than by the calendar: salt, UV and traffic all shorten it. The signal to reseal is water no longer beading and the surface starting to take marks — not a date.
Why nobody can give you one number
Every sealer product carries a manufacturer figure, and every one of those figures assumes conditions your slab does not have. The three things that actually decide the interval are UV load, salt load and traffic.
A north-facing driveway in full Queensland sun ages its sealer far faster than a shaded path. A beachfront pool surround at Caloundra sees salt aerosol that a slab at Springfield Lakes never encounters. A commercial hardstand with delivery traffic wears through in a fraction of the time a domestic entry does.
So the honest answer is a range with reasons attached, and anyone quoting a flat number without asking where you live is guessing.
The test that tells you
Pour a cup of water on the surface. On a sealed slab it beads or sits; the surface darkens slowly or not at all. On a slab whose sealer has gone, the water soaks in within seconds and leaves a dark patch that takes minutes to dry.
That is the moment to reseal — while the concrete is still protected and before it starts absorbing oil, tannins and salt. Resealing at that point is a clean, an abrasion and a fresh coat. Waiting until stains have soaked in means grinding, which is a different job at a different price.
Other signals: colour looking flat and grey rather than deep, chalky residue on shoes, and marks that used to wash off now staying.
How exposure changes it
Full sun. UV breaks down film sealers from the top. On an unshaded north or west-facing driveway, expect the shortest interval of any residential surface.
Coastal. Salt is hygroscopic — it holds moisture against the surface — and it migrates into the concrete rather than sitting on it. Beachfront and canal-front slabs need the shortest cycle of all, and penetrating sealers outperform films there by a wide margin.
Shade and damp. Longer intervals, but only with a breathable penetrating sealer. A film sealer on a permanently damp slab does not wear out so much as blister, which is a failure rather than a maintenance point.
Traffic. Vehicle wheel paths and pedestrian entries wear locally rather than evenly. It is normal for a driveway to need resealing while the path beside it does not.
What happens if you leave it
Nothing dramatic, and then something expensive. Unsealed concrete absorbs — oil in the wheel path, tannin from leaf litter, red soil, salt. Those stains sit in the pores rather than on the surface, so washing does not lift them.
Once staining is absorbed, restoring the appearance means grinding off the stained layer, which is resurfacing rather than maintenance. The cost difference between resealing on time and grinding later is the whole argument for keeping to a cycle.
The questions we get asked
How long does concrete sealer last in Brisbane?
A few years on an inland surface, less in full sun or near salt water, longer on a shaded slab with a penetrating sealer. Exposure decides it, not the calendar.
How do I know when to reseal?
Pour water on it. If it soaks in within seconds and leaves a dark patch, the sealer has gone. If it beads or sits, you have time.
Does resealing need grinding first?
Not if you reseal on time — a clean and a light abrasion is enough. If staining has already soaked in, grinding is needed, and that is a resurfacing job.
Is resealing something I can do myself?
The application, sometimes. The choice of product is the part that goes wrong — a film sealer on a damp slab will blister no matter how carefully it is rolled on.
Does resealing change the colour?
It restores depth of colour that has gone flat, and a gloss sealer will look wetter than a matte one. It will not change the colour itself.
Send a photo of the slab.
We will tell you whether it can be resurfaced, what finish suits it, and what it costs — before anyone turns up with a grinder.