If you've ever watched us work, you might have noticed there's no bucket of soapy water and no squeegee on most jobs. Instead, we use a long pole with a brush on the end that sprays water onto the glass. And then we leave the windows to dry on their own.
It can look like we've skipped a step. In fact, that's the whole point. Here's how pure water cleaning works, and why it gives a better finish than the traditional method in most situations.
What makes water "pure"?
Ordinary tap water isn't just water. It carries dissolved minerals and other impurities picked up on its way to your tap. You can't see them while the water is wet, but when it evaporates they're left behind on whatever it was sitting on.
That's what causes the white spots on a glass that's been left to air-dry, or the marks on a car washed with a garden hose. On windows, the same minerals dry into spots and streaks.
Purified water has had those impurities removed. We use SpotlessWater systems, which filter water multiple times through a membrane over several hours until virtually nothing is left in it but the water itself.
Why purified water leaves no streaks
Because there's nothing dissolved in it, purified water has nothing to leave behind when it dries. We use a brush to loosen the dirt on the glass and frames, rinse it all away with purified water, and let the window dry naturally. What's left is clear glass.
There's another benefit: purified water is very good at picking up dirt. With nothing already dissolved in it, it readily lifts grime off the glass, which is why we don't need to add chemicals or detergents.
No soap, no chemicals
Traditional window cleaning relies on detergent to break down dirt, followed by a squeegee to remove it. Any residue that's missed can attract dirt and leave the glass looking hazy.
Pure water cleaning skips the detergent entirely. That means:
- No residue left on the glass to attract fresh dirt.
- Nothing harsh running off into your flower beds or onto your paving.
- Frames and sills get cleaned with the same pure water rinse, not just the glass.
Can you really clean windows in the rain?
Yes, and this is one of the most common questions we're asked.
Rainwater picks up dust and pollution as it falls, so it isn't pure. Rain on a dirty window mixes with the dirt already there, and the marks you see afterwards are mostly that existing dirt drying back onto the glass.
Once a window has been properly cleaned with purified water, there's very little dirt left for the rain to mix with. The rain runs off, and your windows stay far cleaner than they would if they'd been dirty when the rain arrived. So a shower on cleaning day doesn't mean the job needs redoing.
Reaching the high windows safely
The other half of the system is the pole. Our water-fed poles extend to reach windows up to three storeys high from the ground, so in most cases there's no need for ladders against your home. That's safer for us, avoids ladder marks on your walls or lawn, and means we can reach awkward spots like the windows above a conservatory roof.
There are still times when a traditional hand clean is the better option, for example on some interior windows, and we do that where it makes sense.
What to expect after a pure water clean
If you're used to windows being wiped dry with a squeegee, the first pure water clean can look a little different:
- The glass is left wet. That's intentional. Purified water dries without leaving marks, so there's no need to wipe it, and wiping with a cloth can actually leave smears.
- Don't worry about drips. Water running off frames and sills is purified water too, so it dries clean.
- The first clean or two can take a little longer to look perfect. Windows that have been cleaned with detergent for years often carry a residue that takes more than one visit to rinse away completely. After that, results are consistent.
What it means for your home
Put together, pure water cleaning gives you:
- Streak-free glass, frames and sills.
- A cleaner finish that stays clean for longer.
- No chemicals around your home and garden.
- Safe cleaning at height without ladders in most cases.
If you'd like to see the difference on your own windows, our residential window cleaning service uses this method as standard, and we use the same approach for conservatories, skylights and Velux windows. Get a free quote and we'll take it from there.