Pure water window cleaning, explained
If you've ever wondered why your windows go streaky a few days after a clean, the answer is the soap.
What pure water actually is
Tap water — even soft Welsh water — has minerals in it. Calcium, magnesium, silica. When it dries on glass it leaves a thin mineral film. That film is what you see as streaks. Detergent makes it worse, not better, because it adds surfactants that dry as their own residue.
Pure water is tap water that's been pushed through a deionising filter. The minerals are stripped out. What's left is chemically pure H₂O. When pure water dries on glass it leaves nothing behind — no film, no streaks. The glass is clean down to the molecule.
How we apply it
We use carbon-fibre reach-and-wash poles, fed with pure water from a tank in the van. The water flows out of a brush head at the top of the pole. We scrub the glass, the frames and the sills with the brush, then rinse with pure water and walk away. Air-dries clear.
Pole reach is around 12 metres — that's four storeys from the ground. No ladders. No worker leaning against your wall, climbing your conservatory, scratching your sills.
Why it lasts longer
Because there's no soap residue, there's nothing for dirt to stick to. We typically see pure-water cleans last twice as long between visits compared to traditional soap-and-squeegee — especially on white frames where soap residue used to go grey within weeks.
Why this matters more in Burry Port and Pwll
Coastal properties pick up salt haze in the air. Salt is hygroscopic — it pulls moisture in — and a detergent film on glass holds onto salt. Result: windows look hazy within a week. Pure water leaves nothing for salt to bond to, so the glass stays clear for the full cleaning cycle.
What about rain?
Rain is pure-ish. A light shower after we've cleaned won't streak the glass — there's no soap residue to lift. Heavy rain or storms we'll reschedule, mainly for our own safety.
