The salt haze on Sydney glass: why your windows dull between cleans
The dulling film on your windows is marine aerosol — salt spray carried inland on onshore winds and dried onto the glass. You won't see it building; you'll see it at four in the afternoon when the sun goes low. Purified water and a squeegee take it off completely. Near the water, it rebuilds fast enough that two to three cleans a year keeps glass properly clear.
The film you can't see until four o'clock
Stand at your window at midday and the glass looks fine. Come back at four, sun low over the water, and there it is — a grey bloom across the whole pane. That bloom is marine aerosol. Breaking waves throw microscopic salt particles into the air, onshore wind carries them over your street, and they settle and dry on the glass as a fine crystalline film. It doesn't arrive as dirt. It arrives as weather.
The film builds so gradually you adjust to it. Viewed head-on, the salt crystals scatter almost no light, so the glass reads clear. In raking afternoon light they scatter plenty, and the pane turns milky. That's why windows seem to dull overnight — they didn't. They've been dulling since the last clean, and the light finally caught them out. A dry cloth just smears it around; salt wants to be dissolved, not pushed.
Closer to the water, faster the haze
How fast the haze rebuilds is mostly a function of distance to salt water. A foreshore place in Manly or Mosman can show it within weeks of a clean, especially after a run of onshore nor'easters. A few ridgelines back, in Gordon or St Ives, the same glass might hold for months. Aspect matters too — panes facing the prevailing sea breeze take the load, while sheltered sides stay clearer for longer.
The other variable is rain, and it helps less than you'd hope. Rain rinses some salt off, then dries and leaves the rest behind, along with whatever it collected from the air on the way down. After a blowy southerly change, coastal glass is often worse, not better. So there's no season that solves this. Near the water the film is a standing condition, and the only real lever is how often it comes off.
Purified water and a squeegee, nothing cleverer
Salt dissolves in water — that's the whole trick, and also the trap. Wash with tap water and you dissolve the salt, then redeposit it as the glass dries, along with the tap water's own dissolved minerals. That's the streaky, spotted finish DIY days end in. We wash with purified water, agitate the pane, then squeegee it bone dry, so nothing is left on the glass to dry out. The film comes off entirely, and there's no residue to restart the build.
Two things a clean cannot fix, so you're not surprised. Glass that has carried heavy salt for years can develop faint permanent etching — a clean reveals it rather than removes it. And fogging between the panes of a double-glazed unit is a failed seal, not a film; no amount of washing touches it. Everything else — the grey bloom, the spotting, the milky afternoon haze — comes off, and the difference is not subtle.
The cadence that keeps it clear, and the number
Near the water, the film rebuilds fast enough that two to three cleans a year is the honest cadence — enough that the glass never reaches the milky stage between visits. Further inland, once or twice a year usually holds. Schmick window cleans start at $150; most single-storey homes land between $150 and $550 depending on window count, and two storeys adds about 40%. Bundle it with gutters or a house wash on the same visit and you save 5-15%.
If you'd rather never think about it again, the Keep plan runs $89 a month and puts the schedule on us. Either way, you don't need a site visit to find out what your place costs. The instant quote asks a few questions about your home and returns a firm, bookable price in about 60 seconds — and it holds unless the place is materially different from what you told us. Count your windows, get your number, book the clean.