The BLS unemployment rates aren’t adjusted for seasonal differences. Construction’s jobless rate tends to decline during the peak building season from spring to fall in much of the U.S.

The August jobs totals showed a split among major categories, as residential construction gained 10,800 positions but losses in all other segments outpaced those increases. Non-residential categories—buildings and specialty trades—shed a combined 10,700 positions, and heavy-civil construction’s workforce fell by 6,500.

Architectural and engineering services, a separate BLS category, posted an increase of 2,300 jobs in August.

Ken Simonson, Associated General Contractors of America chief economist, observed that even with August's dip from July in construction jobs, the industry's workforce has expanded by 199,000, or 3.1%, from the year-earlier level. He also said construction's employment has climbed almost twice as fast as the overall U.S. workforce.

Simonson said in a statement that that data and other indicators "suggest contractors would be adding to head count if they could find qualified workers." An AGC survey, released on Aug. 31, found that 69% of the contractors that responded said they are having difficulty filling some craft positions.

Anirban Basu, Associated Builders and Contractors chief economist, said in a statement that contractors' backlogs and margins and difficulty in finding trained workers are signs that the industry is still busy.

But Basu, pointing to the slowdown in nonresidential construction's growth, said, "The biggest culprit continues to be a lack of public-sector capital spending on infrastructure," including highways and water systems.

BLS also reported that the overall U.S. unemployment rate for August held at 4.9%, the same level as in the previous two months, as the economy added 151,000 jobs.