According to the National Women’s Law Center, in 2010 women held a tiny percentage — 2.6 — of the U.S.’s 8.4 million construction jobs, the same percentage they held in 1983. The NWLC faults “barriers such as gender stereotypes, sexual harassment, a lack of awareness about opportunities in construction, and insufficient instruction.”

But while women may not be gaining ground in trades like carpentry and plumbing, they are increasingly getting involved on the entrepreneurial side of the industry. The U.S. Census Bureau counted 152,871 women-owned construction firms in 1997. Ten years later, that number had jumped by 76% to 268,809. Women are steadily chiseling away at that concrete ceiling. Or, as Lenore Janis, president of the National Association of Professional Women in Construction, put it, “Our fingernails are broken from scratching at it.”

For the past 15 years, the Initiative for a Competitive Inner City (ICIC) has compiled its Inner City 100 list, highlighting the fastest-growing urban small businesses in America. This year’s list includes 28 women-owned businesses, a double in percentage since 1999, the list’s inaugural year. While many of these businesses are taking advantage of the burgeoning “mommy market,” several are breaking into industries heavily dominated by men, including construction.

In addition to the efforts of the women themselves, Janis sees the growth as a direct result of a 35-year-old goal set by the Office for Federal Contract Compliance Programs. Since 1978, federal contractors are required to employ women for 6.9% of the total construction work hours on any federal project. (For it’s part, the NWLC says that considering the much higher rates of female participation in other typically male dominated fields like policing, butchering, and machine operation, 6.9% is still “not enough.”)

Shandra Spicer, 32, CEO of the Spicer Group (No. 57 on this year’s Inner City 100), has been running a full-service general contractor and construction management company since she was 18 years old. Coming out of bankruptcy, her father was unable to secure the capital to start a business, so he recruited his daughter to help. “Bright-eyed and bushy tailed,” as she describes herself then, she agreed.

Spicer says she expected to handle only the business end, leaving the construction to her dad, despite the fact that he had no financial ownership stake in the company. But at 23, Spicer learned that she had to take the reins and fully integrate herself into the world of construction. “I was still allowing my father to influence a lot of my decisions,” she says, until he persuaded her to submit a very low bid on a very large project. “At the time I didn’t know enough and I was trusting in my father’s opinion that we could do it even though it just didn’t sit right with me.” When the job was complete, “I ended up leaving by the skin of my teeth with nearly $300,000 in debt.”

Married with a young son and another on the way, Spicer decided it was time to take full control of the business. Over the next 10 years, she learned everything she could about construction, earning certifications, taking courses, seeking assistance through professional networks and government organizations, and eventually working with a mentor to put together a feasible business plan.

Her once-fledgling company pulled in $2.2 million in 2011, but Spicer refuses to take full credit for her accomplishments, doling out gratitude to her mother, her husband (also her employee), and her team. “I ask for help a lot, and I try to hire people that know more than and are smarter than me,” she says. And while she encounters a fair amount of sexism — and as a black woman, racism as well — she doesn’t let it slow her down. “I have to try probably 10,000 times harder than my male counterparts. I can work hard all day long, and then I can drive down the street and say to my kids in the car ‘Guess what, we built that building.’ I have something that stands for a long time, something physical and tangible.”

Genevieve Withers, 52, CEO of Pipe Wrap (No. 82 on this year’s Inner City 100), also got into the construction industry out of financial necessity. “I was looking to start a business that would be able to provide for my two children,” something she couldn’t do as a single mother on a schoolteacher’s salary. “I came across the idea of a quick fix pipe repair kit that could be used to quickly and easily stop emergency leaks.”

It took time to develop the product but, crediting her father’s zeal for experimentation as a research scientist, “instead of walking away and giving up, I just kept trying and trying and trying, until I got the leaks to stop.”

Once Withers finalized her product, she incorporated her business. Since then, the company has moved far beyond low-pressure leaks, and has moved into structural reinforcement and corrosion prevention. Most recently, Pipe Wrap was awarded a National Science Foundation grant to incorporate nanotechnological enhancements to its products.

Like Spicer, Withers credits her staffers for her company’s success. “I don’t do it alone,” she says. “I have surrounded myself with a team of men and women that are very highly qualified in their fields.” She advises other would-be construction entrepreneurs to do the same. “If you don’t know how to do it, get with somebody who does know how to do it and work together to make a better product, because nobody can do anything on their own.”

Despite the low numbers of women in construction, Withers is hopeful that more will enter the industry. “Most men will listen,” she says. “If a woman is in this industry and she has a good product and she knows she does, then there should be no reason on this green earth why she can’t succeed.”