PLUMBING, says Charles Banks, is not a glamorous business. “I tell people at parties that I’m a toilet distributor,” he grins. “Then I wait to see their reaction.”

Banks has headed Wolseley, the British firm that has become the world’s biggest plumbing- products distribution business, for four years. In that time, sales and profits have surged, and the share price — nearing £10 last week — has doubled, giving the company a market value of almost £6 billion. Banks, an avuncular 64-year-old American, can afford the odd wisecrack.

Yet many outside the building trade have no idea what Wolseley does. Makes socks? Banks has heard them all. In fact, it owns the Plumb Center and Build Center chains in Britain, and similar operations in America and continental Europe, with a huge trade customer base. But previous bosses, while building Wolseley into a FTSE 100 world beater, had decided that a low profile for the group was the smart approach.

“I was told, ‘Charlie, if you stick your head up, people will want to shoot it off’,” says Banks. “But we have thousands of investors and we have an obligation to let them know how we are doing.”

And the answer is: pretty good, at the moment. Sales topped £10 billion last year, and double-digit growth is promised by Banks for this year, as for every year since he took over. That is achieved through a mix of continual acquisitions — another four, costing £41m, announced last week — and organic expansion, and the business world is beginning to take notice.

Last month Wolseley, which does two-thirds of its business in America, emerged in the top 10 of Britain’s most admired companies in a survey by Management Today magazine, and many now rate Banks among the most successful American bosses over here.

But let’s not embarrass him too much. “I think some British colleagues thought I was out to build my ego, but this is not ego building, this is about building the company.”

Banks brings an interesting mix of qualities to Wolseley. Co-workers describe him as a hard-driving boss who has pushed his way up from the bottom, has few airs and graces, and prides himself on his inquisitiveness, competitiveness and straight talking.

There’s an old-fashioned quality to his leadership, too: no computer on his desk, a reliance on one-to-one briefings, a gravitas that goes with his early training as a US Navy officer followed by four decades spent inside the same business. Add to that a folksy, brown-eyed charm that can wrap up an audience in seconds. Tall, silver-haired and solidly built, Banks is a leader confident enough to send up his own quirks.

“Look at these,” he says, holding up his meaty, labourer’s hands and bemoaning his inability to work modern technology. “I’ve been given a Blackberry but with these fingers, I’m pressing two numbers at once.”

He laughs. Sitting in his second-floor sanctum at Wolseley’s business-park head office outside Reading, Banks is, you would imagine, pretty practised at reassuring sceptical Brits. Previously boss of Ferguson, Wolseley’s American plumbing-supplies arm, he arrived here four years ago with a clutch of ideas on how he wanted to make the size of the group pay off, and practical experience of what annoyed him about reporting to a foreign head office.

“I didn’t think we were creating enough value for the companies that were part of Wolseley, and I didn’t think we were telling our story,” he says. “There had to be some value in putting it all together. There was lots of talent here, creative ideas and buying power, but how do you go about it?” Since then he has rewritten the Wolseley rulebook, moved the head office nearer to Heathrow, shifted his own home from Virginia to Wiltshire and set about establishing a more integrated approach at the company, with a senior team that reflected his own, can-do attitude. Pessimism, he says, comes too easily to some Brits.

“One told me, ‘Charlie, don’t you know a pessimist is never disappointed?’” Banks rolls his eyes at that one.

Times Recommends

• Lies and cover-up at MG Rover exposed by report
• High oil prices push manufacturing costs up
• Primark founder steps down as chief executive