At a conference addressing skills shortages in the sector, Unite assistant general secretary Gail Cartmail warned that long hours and tough working conditions were factors behind the high suicide rate among builders.
The latest official figures show that low-skilled male construction workers are 3.7 times more likely to kill themselves than the national average.
“This is a very, very serious issue,” Ms Cartmail, who leads on construction issues for Unite, told the conference.
She called for better mental health support alongside direct employment of workers, a “social dialogue” between bosses, government and unions, and decent working standards as a route to address the chronic shortage of skilled labour in construction.
The conference also saw union officials clash with senior civil servants over bosses’ use of foreign labour to undercut local workforces.
Under the EU posted workers directive, British firms are allowed to pay groups of workers from abroad only the minimum wage rather than the agreed rates for the job.
Unions argue that this has led to workers being employed on construction projects for the specific purpose of undermining collective agreements — and shutting local people out of jobs.
Department for Business, Energy and Industrial Strategy steel team deputy director Fergus Harradence asserted that the “truth is that the majority of [foreign] workers end up getting paid the same as their UK counterparts.”
But speaking from the floor, GMB national officer Phil Whitehouse said: “You ought to get your boots on and get out on the sites. Wake up, it’s happening.”
Ms Cartmail said that where workers from other countries were being paid the same rate, this had often only been achieved “by taking industrial action.”
“The burden of social conscience shouldn’t be on the shoulders of employees. No ifs, no buts,” she insisted.