As construction employment expands in many parts of the country, many firms are having a hard time finding enough qualified workers, according to the Associated General Contractors of America (AGC).

A survey conducted by SmartBrief, in partnership with AGC, found that two-thirds of firms report having experienced labor shortages during the past year. Twenty-five percent of firms reported they turned down work during the past year because of a lack of labor, while 70 percent of firms reported they are paying more for skilled labor than they did last year. Thirteen percent of respondents described those wage increases as “significant.”

Responding firms noted that carpenters, project managers and supervisors are currently the hardest positions to fill. According to AGC, they are also having difficulty finding qualified laborers, estimators, electricians, plumbers and ironworkers.

Meanwhile, according to a new analysis of federal employment data by AGC, construction employment expanded in 223 metro areas, declined in 72 and was stagnant in 44 between July 2013 and July 2014.

“Many construction firms looking to expand their payrolls are finding a surprisingly tight labor market,” says Ken Simonson, the association’s chief economist. “These expanding labor shortages threaten to impact construction schedules as firms struggle to find enough qualified workers.”

Dallas-Plano-Irving, Texas added the largest number of construction jobs in the past year (9,400 jobs, 8 percent), and the largest percentage gains occurred in Lake Charles, La. (27 percent, 2,900 jobs).

The largest job losses from July 2013 to July 2014 were in Phoenix-Mesa-Glendale, Ariz. (-4,800 jobs, -5 percent), while the largest percentage decline for the past year was in Steubenville-Weirton, Ohio-W.V. (-22 percent, -400 jobs).