Amid signs that demand for new construction may be softening in some areas, hiring in the industry slowed in April. At the same time, unemployment fell to just 6 percent, adding to concerns that a shortage of skilled labor could delay or defer future projects, further impeding growth.

With fewer men entering the field, companies could help fill the employment gap by recruiting more women. But that will require changes that, up until now, the industry has been reluctant to make.

Based on its analysis of the latest U.S. Bureau of Labor Statistics job numbers, the Associated Builders and Contractors (ABC) finds the nation's construction industry added only a net 1,000 new jobs in April, with some trades adding workers while others cut back. Even so, nonresidential building employment is up by 25,500 jobs or 3.5 percent on a year-over-year basis, while residential building employment is up by 37,500 jobs or 5.4 percent.

Of greater concern than the slowdown in hiring is the shrinking pool of unemployed workers. The National Association of Home Builders (NAHB) reported the count of unfilled jobs in the overall construction sector reached a post-Great Recession high in February. NAHB notes its surveys show access to labor remains a top business challenge for builders.

The long-term employment outlook does not bode well for the industry either. A recently released report from the World Economic Forum, "Shaping the Future of Construction," predicts the industry "will face stiff recruiting and talent challenges in the years ahead." Competition from other fields and an aging workforce will continue to deplete the supply of skilled labor, unless steps are taken to reverse the trend.

One needed change, states the report, is to "increase efforts to achieve gender equality in construction." That, say the report's authors, will require "not only making changes to recruit more women, but also recognizing and building on the strengths and characteristics of women."

According to the National Association of Women in Construction (NAWC), women made up less than 9 percent of all people working in construction in 2014, including administrative positions.

Despite efforts by governments and educational institutions to recruit and train more women and having one of the narrowest gender pay gaps of any industry ($0.92 for every dollar a man earns vs. a national average of $0.78), women have been slow to seek jobs in construction. The Boston Globe reports, for example, although the city passed an ordinance in 1983 to increase women's employment in construction to at least 10 percent, actual participation reached only 2 percent by 2008 and 4.4 percent in 2014.

While more women today are considering jobs in construction, obstacles remain. Construction traditionally has been a male-dominated industry, and men have been reluctant to accept female co-workers as equals. Some women say the situation is improving as more women choose careers in the industry, while others complain that sexism, harassment and bullying are commonplace and often unchecked by supervisors and upper management.

The relative scarcity of female co-workers within a given firm or city makes it difficult for women to find role models or mentors, and to attract other women into the industry. Most women who choose to go into construction have been influenced by a male family member or relative who has worked in the industry. Taking time out to have a family or arranging for childcare is yet another challenge.

New technologies and processes already in use can help level the playing field and open up opportunities for women in construction, but the industry also needs to undertake a culture change to make the work environment more supportive and attractive to women. The impending labor shortage may be just the leverage it needs.