The first unwritten rule of the city’s scaffold and sidewalk shed industry is that each company must stick to its own color. For years, the miles of temporary roofs over sidewalks throughout the city have tended to be confined to a few shades of blue, green, and gray corresponding to the handful of businesses in the local industry.

In the past two years, the owner of Everest Scaffolding Inc., Christopher Downes, has introduced a distinctive hue (he terms it “sandstone”) into the painted plywood palette of the temporary structures erected over so many sidewalks in Manhattan, as he has vaulted his company into the limited local field of major industry players.

Since it started in late 2004, the business has grown to 40 employees from four — to more than 7,000 sections of scaffolding from 100 — at a time when the industry is seeing a tremendous amount of business from both new and recurring construction.

Mr. Downes, 41, is an effusive onetime dairy farmer who immigrated to America when he turned 20. Pushed out of Ireland by a sluggish economy and distaste for the smell of cows in the morning, he says he worked his way up the local construction industry ladder to become a sales representative for a now-rival scaffolding company. Eventually, he saw there was room for another business in the competitive market, and made his foray into New York City’s scaffolding scene.

“The only way the Irish will ever get to the top of Mt. Everest is with the help of scaffold,” Mr. Downes said of his reasoning while naming the company.

If not because of the name, Mr. Downes unabashedly boasts that Everest’s rapid expansion comes partially as a result of his tremendous salesmanship skills, on top of the self-promoting nature of the sidewalk sheds.

“Once your product is on the street, it sells itself — the more locations you have, the more work you get, so people will presume you’ll do good work,” Mr. Downes said.

Fueling the growth has been a city regulation, Local Law 11, a thorn in the side of building owners that requires exterior examinations of buildings of more than five stories every five years, an act that almost always requires the installation of a sidewalk shed as work is competed overhead.

The most recent inspection period ended in February —building owners may get extensions — and scaffolding company owners say a bulk of their clients seem to wait until the last year, creating a sudden flow of business.

While the vast majority of Mr. Downes’s work comes as a result of Local Law 11, competitors have also benefited from the building boom and sharp increase in renovations and restorations that have overtaken New York in the past few years.

According to numbers provided by the city’s Department of Buildings, the city issued 1,094 initial permits for scaffolding in 2006, up from 809 the prior year and 513 in 2001.

As of February 28, the most recent data available, there were 5,160 active sidewalk sheds throughout the city, up from 3,471 in the winter of 2003.

As the number of jobs has shot up, so too have the number of companies vying for them, the president of the Hoisting and Scaffolding Trades Association, Kevin O’Callaghan, said.

“Certainly high tide is lifting all the ships. There’s a lot of good work out there for hoisting and scaffolding companies,” he said.

The number of nonunion scaffolding companies has grown about tenfold in the past few decades, Mr. O’Callaghan estimated, pushing union-staffed companies such as his own to concentrate on larger projects.

As Mr. Downes snatches up an increasing number of contracts around the city, the accompanying rapid expansion of his company has caused some growing pains.

“You want to buy the company?” Mr. Downes asked repeatedly in an interview, as he carped about debt, insurance costs, and complaints he receives from pedestrians ruffled by a dropped nail or a rude worker on his crew.

“Everyone has a cell phone — they just call up and complain — they say, ‘Oh your guy whistled at me,'” he said.