EXTRACT FROM THE GUARDIAN NEWSPAPER 31 OCT 2009

We are standing in the driveway of a perfectly manicured bungalow in the outer suburbs of Bournemouth. Already I'm wondering if the burden of profiling this innuendo-laden occupation might not prove too much, and not just because When I'm Cleaning Windows – George Formby's cheeky ukulele homage to the trade – has been jangling around my head all afternoon.

In his smart blue fatigues, the pole and brush in his hand is hooked up, via the yellow hose, to the water supply in the van; he twizzles a small valve on his belt and a jet of water squirts from the end of his brush.

"Now the technology's there, the job's a lot easier," he admits, briskly scrubbing the bungalow's front window. "When I started 10 years ago, you could set up for a hundred quid and still make an OK living. But I fell off my ladder twice in the first two years. It was horrendous." Fortunately he escaped serious injury, and when he was tipped off about a new system that would let him reach six floors up without a ladder, little further encouragement was needed.

We peer into the back of his pristine van, which, far from containing an assortment of sponges and buckets, is half broom cupboard, half scientific laboratory. Besides his poles, neatly racked inside the roof, there is a very large water tank, two reels of bright yellow hose, something resembling a traffic cone, and a digital sensor that monitors the pump flow of water from the tanks through the pole to the end of his brush.

No doubt Formby would have been pleased to see there is still an honest bob to be earned from window cleaning, although he might have struggled to work some of the modern-day technological nuances into his lyrics; for example, the distinction between "pure water" and "tap water", which I had assumed was just marketing blurb. "Oh no," he says, earnestly. "It goes through six filters and it's absolutely pure. Tap water is 400 parts [impurities] per million; this is zero. If it goes over seven parts per million, it leaves marks on the windows." Critically, the water's purity means it needs no detergent and no wiping afterwards, speeding up the job considerably.

How could I have failed to notice the advent of window cleaners transporting 1,000 litres of their own microfiltered water around with them? Part of the reason is that many of us never see them at work. "About half my customers are never in when I come round," he points out. "Some of them I've never met in five or six years of cleaning their windows." "Anyone can get a window wet and it looks clean," he says dismissively, sploshing water over a double-glazed patio door. "But if you use water that's not pure, it'll go all spotty and smeary."

We drive a few doors down the street to a large semi-detached house, where the owners are out and the side gate locked. "Here's another common problem," he says, leaping swiftly onto the side wall and vaulting straight over the top, dragging his hose behind him. It's easy to forget the amount of trust we place in the hands of people who work around our properties. "I've been jumping over gates for 10 years – all the big millionaire places – and only ever been questioned once," he says, with bemusement. "The amount of people who leave doors open is ridiculous they've got dogs, so they leave the patio doors open. It's amazing."

Still, it rankles that many people don't view window cleaning as a worthy occupation. "To tell the truth, I often get a bit embarrassed telling people what I do," he says, looking genuinely affronted. "I might earn two or three times what they earn but I still feel 'only a window cleaner'. It's a bit of a sore subject, to be honest."

But before he heads back to his office, I'm hoping he'll reveal all, and spill the beans about some of those things he really shouldn't have seen on the job. “You can't see stuff with the poles, short of putting a camera on it."