She hadn’t always planned to be a part of the sheet metal industry. In fact, in 1979, a year after graduating high school, she obtained her real estate license. However, the 19% interest rates at the time made real estate a challenging field, prompting her to seek alternative employment. 

“My dad and my uncle had two roofing companies and a sheet metal company, and I was cleaning houses for my broker to pay the bills because I wasn't selling a lot of real estate,” she says. “In January, my dad offered me a job at one of the roofing companies, which I declined. By February, he offered me a job at General Sheet Metal — and I was hungry so I took the job.”

That was in 1982 and, 42 years later, she’s the CEO.

Road to leadership

During the early years of her career, Duncan met her now-husband, who also worked at General Sheet Metal. They married in 1986, that same year, Duncan’s dad was ready to leave the business. While her husband was hesitant to get involved, Duncan wasn’t prepared to let go.  

 “I suggested my husband buy the stock, but he wasn’t interested. So, I offered to buy my dad’s stock, but he said ‘nobody will ever work for a woman.’ It was just a sign of the times. It’s just that generation,” Duncan explained. Nevertheless, she persisted, sending her father checks. By 2000 she had purchased her two brothers shares in GSM. By 2011, her husband retired from the company and in 2012, she bought her dad out of the business.

The company’s growth skyrocketed under her leadership.

“In 2012, our volume was $9 million. By 2019, our volume was $55 million,” Duncan said.

One of the most significant changes was transitioning GSM to an Employee Stock Ownership Plan (ESOP) in 2018, completing the sale in 2023.

General Sheet Metal is owned 100% by its employees. 

“This shift reflects our commitment to inclusivity and empowers every member of our team to contribute actively to share success,” Duncan says, crediting her daughter for advocating the move to an ESOP. 

SMACNA involvement

In 1996, Duncan attended her first SMACNA convention, and a year later, she got on her first committee. Her extensive involvement, particularly related to PAC and legislation, eventually led her to becoming SMACNA president. 

“Probably one of the biggest reasons why I grew my business is because of my connection with the SMACNA family. I was mentored by so many people in this organization, many of whom have retired or passed on, yet their knowledge continues to strengthen our business,” she said. 

One significant issue Duncan has worked on is pension reform.

“I testified in front of Congress on pension reform. As a business owner, we faced unfunded liabilities that were not our fault, yet we had to address them to secure my company’s future and at that time, my daughter’s inheritance,” she explained. Despite numerous challenges, including two extremely large economic downturns, Duncan’s advocacy efforts helped bring about substantial improvements to the pension issue.

Inclusive Leadership and BE4ALL

Creating an inclusive environment is something Duncan is passionate about.

“We must build a workplace where everyone feels included, seen and valued, regardless of their background,” she asserted. Duncan believes that fostering a culture of inclusivity not only helps retain employees but also attracts new talent though positive word of mouth.

Throughout her 42-year career, Duncan has achieved many successes, but she attributes much of her growth to her mentors. “Being the first woman contractor elected to the College of Fellows was an honor, especially being nominated by my peers. It was a significate recognition of my contributions,” she reflected. Duncan’s journey is a testament to her resilience, innovative mindset, and commitment to fostering an inclusive and successful business environment.