Larry Lopez, president of construction staffing service Green JobWorks in Baltimore, Maryland, needs about 20 skilled workers — a tall order for any small employer in a tight labor market. But even available workers often lack the experience he needs, Lopez says.

"A lot of clients are asking for people who can operate tools like chipping hammers and saws. And the folks that are unemployed and coming into the industry, they find themselves without a lot of experience," Lopez said. "It's difficult because they don't have the skills necessary to perform for our customers."

To combat the competitive market, Lopez offers benefits including health care, paid time off and annual raises. At Green JobWorks, workers are employees, not contractors.

"Having employees really feel like they are permanent here and that there are opportunities attracts them. I think having some kind of ownership and belonging to the company, because we are doing our own projects, is a benefit I don't think any other staffing company is doing," he said.

Offering higher pay, better benefits and on-the-job training — and reaching out to groups of people who don't fit the traditional mold of a construction worker — are just a few of the ways construction companies are dealing with an acute labor shortage.

Indeed, the strong U.S. economy is affecting the construction industry in two ways: The boom is boosting spending from consumers and businesses who have more cash on hand for expansions and improvements, but it's also exacerbating the industry's growing inability to fill jobs.

"We are projected to have about $1.3 trillion in construction spend this year," says Mike Bellaman, president and CEO of the trade group Associated Builders and Contractors. Over a year, the construction industry has added 330,000 jobs. But Bellaman says it's just getting started. "We still project that we have another 400,000 to 500,000 jobs ready to be filled. And if we continue to grow at modest rates and if we get an infrastructure package — say $100 billion a year over 10 years — we could add another 700,000 jobs."