By comparison, March saw a strong gain of 41,000 jobs, a total that was revised upward by 4,000 from the initial BLS estimate.

The weakest construction sector in April was residential specialty trade contractors, which lost 10,900 jobs in April. Heavy and civil engineering construction shed 2,200. But buildings construction picked up 8,200 jobs and nonresidential specialty trades firms gained 5,500.

Ken Simonson, Associated General Contractors of America chief economist, suggested that construction firms may have shifted the timing of their hiring this year. He said in a statement, "Some of the slowdown in hiring last month was due to mild winter weather that allowed contractors to hire or retain workers in the first quarter instead of waiting until spring."

Simonson added that contractors' reports and federal data on construction spending "suggest industry demand for workers will remain robust, if firms can find employees with the right skills."

Anirban Basu, Associated Builders and Contractors chief economist, said that nonresidential construction spending recently has been soft, which, if it continues would affect employment levels.

But Basu added in a statement: "For now, increased spending on hotels, office buildings, data centers and warehouses related to e-commerce is helping support nonresidential job creation. The bigger issue for contractors is not excess labor, but difficulty locating appropriately skilled labor."

The BLS construction unemployment rates aren’t adjusted for seasonal variations; the jobs totals are seasonally adjusted.

The overall national unemployment rate was 5% in April, the same as March’s level, as the economy added 160,000 jobs, BLS reported.