NORTH READING – Providing top-notch customer service and treating longtime employees as family are merely two strategies that have kept Moynihan Lumber in business for a half century.The company, which opened its doors in North Reading on Oct. 1, 1959, has since added a location in Beverly and another in Plaistow, N.H.Saugus natives, brothers and co-owners Michael, Jack and Gerard Moynihan have steered the business through good times and bad and on Thursday will celebrate Moynihan Lumber’s 50th year as part of the region’s building supplies community.According to Gerard Moynihan, 68, of North Reading, the secret of their success is due to the company’s philosophy, which has remained unchanged.”Our goal is to offer quality products at competitive prices and provide service second to none,” he said.The Moynihan family roots can be traced to the early 1900s, when the late John and Arthur Moynihan – uncles of the current owners – delivered lumber by horse-drawn wagon. In the 1930s, the family owned lumberyards in Revere and Watertown.As they grew up, first Michael, then Gerard and finally younger brother Jack, worked part-time for the family business. They all graduated from Saugus High School, in 1954, 1959 and 1963, respectively, then went on to Holy Cross College.The Watertown operation, MacLeod & Moynihan, was sold in 1965. The North Reading lumber yard by then had grown from three wooden buildings on four acres along a dirt road to eight buildings on 13 acres with 80 employees.”In those days, when materials had to be delivered to a customer, Michael and his uncle would leave the lumber yard unattended with a notepad on the door. If a customer came by while they were gone, they were asked to write down how much they took and were billed later,” said Gerard Moynihan, recalling that sales transactions were configured on note paper without the benefit of an electronic calculator. “If we made a mistake on the bill, I would stop at the customer’s house on my way home, explain the overcharge and give them the balance due. People really appreciated that.”Those were different times. The lumber yard had no perimeter fences or gate until the late 1960s when an insurance agent insisted they install barbed wire if they wanted a policy. “It was one of the saddest days,” Gerard Moynihan said. The era of trust was over.From the mid-1960s to the early 1970s, Betty Moynihan – mother of the three sons – served as the lumber yard bookkeeper, while their father worked at GE in Lynn. “As you know, the language in a lumberyard can get rather salty,” he said. “So a system to appease Mrs. Moynihan was developed by a contractor, Eddie Carlson. When she was working, a red flag was flown indicating to everyone to watch their language. On the days when she wasn’t working, a green flag was flown. Everyone respected the code and Mrs. Moynihan never knew the flags were flown for her benefit.”Hard times in the 1970s forced the brothers to reexamine their credit practices as informality gave way to customer contracts. In 1976, Moynihan Lumber became the first lumberyard in New England accepted by the Ace Hardware chain. The business was changing, so that hardware – tools, paints and a door-and-window showroom – shared space with lumber stocks. The age of the do-it-yourself homeowner had arrive.During 1986, Moynihan Lumber purchased the former Knight Lumber Co. in Beverly as a secondary site. As the housing boom spread to southern New Hampshire, the Moynihans searched for a third site within easy access to the surrounding highways. They found it in Plaistow, N.H. in 1995.”Our biggest asset is our people,” said Michael Moynihan, 72, of Reading. “We have employees for a lifetime. Our oldest employee started in 1965. We are a family business, not just our family, but we employ families. People stay because they know we care.”As Jack Moynihan, 64, of Lynnfield, put it, the company has benefited from dedicated, loyal family members and employees who over the years