WASHINGTON, D.C. — Construction companies no longer fret over finding work. They increasingly worry about finding enough skilled workers.

“The industry’s workforce challenge is primarily a craft-worker shortage,” said Stephen Sandherr, the CEO of the Associated General Contractors of America, adding that skilled hourly workers represent “the bulk of construction workers.”

The worker shortage, highlighted in the group’s new survey of members, is all the more pronounced this Labor Day weekend because of indications that demand will grow for roofers, plumbers, electricians, carpenters and concrete masons — the very positions in shortest supply.

The U.S. Labor Department projects that demand nationwide for all those categories, except for carpenters, will grow considerably faster over the next decade than the pace of overall job growth.

Presidential candidates Hillary Clinton and Donald Trump are promising infrastructure spending to boost employment, but where are those prospective workers who will build new bridges and highways?

“You can throw money at it, but you’ve got to figure out a way to train people to build these projects,” said Ron Brown, executive vice president of State Utility Contractors in Monroe, N.C., which installs water and sewer pipelines. “You can put in all the money in the world, but if there aren’t enough people out there to build it, it can’t get built.”

Labor Department data shows that demand for masonry workers is expected to grow by 15 percent from 2014 to 2024. That’s more than twice the rate of projected overall 7 percent job growth in the same period, according to the Bureau of Labor Statistics.

Similarly, demand for electricians is projected to grow 14 percent over that 10-year period. Demand for roofers is expected to grow by 13 percent and for plumbers by 12 percent. Only demand for carpenters nearly matches the overall growth, projected to rise by 6 percent.

The government data lines up neatly with what construction firms are reporting in the membership survey released Wednesday by the contractors’ group.

“These worker shortages are occurring at a time when many construction firms have a low opinion of the pipeline for recruiting and preparing new craft workers,” the survey noted in a summary. “Three-quarters of construction firms that responded to this survey rated that pipeline as poor or fair, while only 14 percent said the craft-worker pipeline was good or excellent.”

Take North Carolina. The group’s survey said 79 percent of participating members in the state expected to expand and hire more hourly workers in the next 12 months, but 84 percent reported difficulty in finding skilled hourly craftsmen right now.

“The availability of people, they’re just not out there,” Brown told McClatchy. “We have a lot of baby boomers” but “There just aren’t enough younger people coming in.”

Next door in Georgia, there’s a 5-to-1 ratio of older skilled workers leaving versus young ones joining the construction force, said Mike Dunham, CEO of the contractors’ group in Georgia.

“They’re leaving our marketplace and we’re only putting one person back in the marketplace,” he lamented on a conference call discussing the survey.

In the survey of 1,500 members, the association said companies were dealing with the shortage by increasing hours, pay and benefits.

Almost half of the companies surveyed — 48 percent — reported that they had increased base pay for craft workers because of shortages. Some 47 percent said they were increasing overtime hours.

“I don’t think there is a worker shortage as much as a shortage of exceptionally cheaper labor,” said Jay Hodges, who runs programs in western Missouri and Kansas for the Laborers-Employers Cooperation and Education Trust, which works with contractors and the Laborers’ International Union of North America to bid on projects. “There is a lot of work going on, and the guys are not stupid. What they’re finding is … they can get more than $8 or $10 an hour to do the work.”

Hodges, based in Kansas City, agreed that retaining skilled labor is a growing challenge.

“They have other options, which is an option we used to not have,” he said.

The contractors’ survey found that hourly craft construction workers were reported in short supply in all four regions of the country. It was most pronounced in the Midwest, where 77 percent of firms reported shortages, and the South, where 74 percent did. About 71 percent of companies in the West and 57 percent in the Northeast reported worker shortages.

Companies are grooming entry-level workers with an eye toward retention.

“The quality of our entry-level craft workers is of concern, and companies have to spend more time and money training these entry-level workers,” said Nancy Munro, executive manager of MidMountain Contractors Inc. in Kirkland, Wash., which specializes in utility and roadway construction.

One potential solution to the worker shortage is allowing in more skilled migrants or finding a way to legalize those who are already here.

“The association has long championed immigration reform,” said Brian Turmail, spokesman for the contractors’ group, which favors a temporary loosening of restrictions to address the worker shortage. “We see, as a short-term measure, making it easier for persons with construction skills to legally come into the country.”

Contractors say the current approach puts the onus on them to determine whether someone is in the country legally; they want the government to take responsibility.

One longer-term solution is more vocational training in high schools and community colleges, something manufacturers and contractors have been pushing for a decade. The nature of manual labor has changed. Perceptions haven’t.

“The equipment we run is computerized. When you’re moving dirt, the machines are computerized. We use lasers,” said Brown. “They think, ‘I’ll be digging a ditch with a shovel the rest of my life.’ And it’s nowhere near that.”