Century-old John A. Dalsin & Son is a low-profile pioneer of the Twin Cities commercial roofing trade.

The company has topped hundreds of buildings, including the high-profile likes of the St. Paul Cathedral, the IDS Center, Gaviidae Common, the Mall of America and a sprawling Nissan car factory in Smyrna, Tenn.

Bob Dalsin, the 31-year president and grandson of founder John Dalsin, recently ticked off a number of company innovations over the years, including cranes to lift roofing material, tanker trucks filled with hot asphalt (replacing tubs) and the latest variations of energy-saving "green roofs."

Dalsin had to be innovative to survive the real estate bust that began in 2008 when commercial projects came to an abrupt halt as the financial crisis morphed into the Great Recession. It was the economic opposite of commercial real estate's go-go years in the late 1990s.

"Roofing service, re-roofing and repairs got us through the last decade, particularly the last six or seven years," Dalsin said, dropping the names of a few outfits that have gone out of business or seriously retrenched.

"When one of our competitors fails, their sales people and foremen just start another roofing company," Dalsin said. "That makes it competitive for the available work. Our gross profit margins have gone from about 40 percent in 1996 and 1997 to 20 percent lately."

Indeed, John A. Dalsin's revenue has been flat -- about $15 million annually over the past decade. Dalsin shrank from 140 to 100 employees.

Dalsin said in an era of cost-cutting, as building owners shop for lean bids among business-hungry commercial roofers, it's been old-fashioned customer service and repeat business that's kept John A. Dalsin afloat as much as new labor- or energy-saving wrinkles in roofing material and application.

Several years ago, John A. Dalsin put a roof atop a new building at Mystic Lake Casino in Shakopee. Several Dalsin employees were given tickets to a boxing match at the new venue. When they entered the building amid a furious thunderstorm, two of them checked the roof and found leaks. They noticed that the mechanical contractor who had finished the job hadn't completely sealed the openings around the heating and cooling equipment.

"Our guys had sealed the roof before the casino management really noticed or needed to make a call," Dalsin said.

About four years ago, while the company was installing a new roof on an old high school in Creston, Iowa, the town was hit by terrific winds. The roof held, but the Dalsin crew stayed a few extra days at no extra charge to help replace broken windows and clean up the mess.

"We try to keep customers informed on the progress of our work, do the job right and stand behind our work," said Doug Spoden, a 28-year employee who is construction superintendent.

It also helps that Dalsin several years ago invested in a top-flight information-services system that allows job foremen to fax in from home every evening an assessment of the day's progress so the home office can track it against the original estimate.

John A. Dalsin commenced operations in 1912 in a little storefront on Bloomington Avenue S. in the Phillips neighborhood. In 1975, the company consolidated its operations to a five-acre campus in the same neighborhood near Hiawatha Avenue and 28th Street.

Bob Dalsin, 70, a trim, fit fellow who looks a decade younger, started working for his dad, Russ, when Bob graduated from college in 1964.

Dalsin has two sons in the business, but he isn't ready to concede the reins yet. For one thing, he'd like to see a business uptick replace years of layoffs and some wage freezes.

"Our roofers work hard," said Dalsin, who is a trustee of the national union pension fund that he said is fully funded.

"I don't know where the business will go, but until there's more demand, we won't expand," he said. "I don't have to be here all the time. We have great people. But I still enjoy going to work."

Neal St. Anthony • 612-673-7144