The real estate bust idled hundreds of thousands of construction workers. Now, with housing on the mend, builders are hiring again.

Trouble is, many workers aren’t coming back.

Years of sporadic employment drove many from the industry. Incomes aren’t what they used to be. Laid-off workers remember the sting of lost livelihoods; some have had enough of boom and bust.

Former house painter Alan Schaffer has hung up his paintbrush to pursue a degree in business administration. The Riverside County, Calif., resident says he’s looking for a livelihood that’s stable.

“I love construction. I love building,” said Schaffer, 45. “But I can’t have a job that pays me $50,000 one year and zip the next. I need to be more financially secure.”

With home prices surging across the country, builders are again seeing big opportunities. Housing starts and new-home sales are up. But even with high unemployment, construction companies say they’re struggling to find enough qualified workers to keep up with demand for new homes.

“We’re starting to see spot shortages of labor,” said John Nunan, president of Unger Construction, a commercial building contractor that does work in Northern California.

Many experienced union workers retired during the slowdown, he said. Others found new careers. Now, many contractors can’t find all the workers they need.

Part of the problem is pay. Workers’ earnings in the construction industry fell more sharply — and are now recovering more slowly — than those in many other industries. Hourly pay for construction workers, adjusted for inflation, was $11.22 in 2012, down 3.1 percent from 2009.

Normally, worker shortages push up wages. But builders say they can’t match what they paid before the recession. Costs for building materials are rising. So are land prices in many areas.

Many laborers are grateful just to be working again. Still, hard hats such as Danny Fregoso, a supervisor at Joseph Holt Plastering Inc. of Corona, can’t help but miss the fat paychecks that accompanied the housing bubble.

During the best of times, Fregoso said he made about $26 an hour, while entry-level workers were making about $17 or $18. These days, he’s earning about $16 an hour.

Stagnant wages aren’t helping lure workers to job sites in Arizona’s brutal desert heat, said Brett Jones, vice president of operations at the Arizona Construction Association.

Arizona’s tough new immigration laws, passed in 2010, aren’t helping matters either, advocates contend. The U.S. Supreme Court later found parts of that legislation unconstitutional. Still, thousands of Latinos have left the state.

Meanwhile, the flow of migrants north from Mexico and Central America has slowed substantially, in part because of tougher enforcement along the U.S.-Mexico border.

The U.S. construction industry depends heavily on Latino labor. At the height of the boom, Latinos made up one-quarter of the U.S. construction labor force; most of them were foreign-born, according to the Pew Hispanic Center in Washington.

“The work force has gone somewhere else,” said Richard Usher, who runs an insurance company for construction firms and is also co-founder of Arizona Employers for Immigration Reform. “They had to feed their families.”