Image caption The shock of an employee's suicide prompted building firm Jehu to tackle mental health issues, says Vince Alm

"He was a popular lad, one of the boys... No-one had a clue he was suffering."

Vince Alm, contracts manager at construction company Jehu, said he was "shocked" to find out one of his labourers had killed himself.

According to latest statistics, the industry where mental ill health is most acute is construction.

This is an issue building firms say they are working hard to address.

Men in the building industry are three times more likely to take their own lives than men on average, according to the ONS figures .

Since their employee's death, Jehu have put in measures to try to tackle poor mental health, including visits from charities to encourage the workers to talk if they need to.

"We all like to think we're macho but we all suffer the same problems. There is help out there and things do get better."

Jehu is not the only construction company in Wales offering support to workers.

The building firm Bouygues is also concerned and has brought in mental health first aiders to lend support and spot people's troubles early on.

Its corporate social responsibility director, Leigh Hughes, said they needed to make it clear that "it is OK to not be OK".

He said workers are often on their own for a long time each day, for instance working on a crane, digger or a tractor.

Image caption Nick Toulson has learned to manage his mental health problems that arise in "fits and starts"

Bouygues community engagement officer Nick Toulson, 49, has worked in construction for eight years - and has suffered with depression since his early teenage years.

"I hope people realise there are a lot of people out there who are struggling at different levels," he said.

In his early twenties, his father died just after he himself became a father and endured a series of "life stresses".

"It got really bad, I went through a couple of periods in my life... I describe it as standing on the edge of the abyss."

He is thankful for his supportive partner and the medical help he received to help him deal with his mental health problems when they arose.

"Bottling your feelings up, bottling your depression and anxiety up, is probably one of the worst things you can do... It's really important to talk, whether that's chatting over a cup of coffee with your work colleagues...or getting an appointment with your GP."

Unhappy workers

The personal cost of mental health problems can be enormous, but it also has a wider impact on the economy.

The ONS estimated that stress, anxiety, depression and serious mental illness caused at least 15 million days of sickness absence in the UK last year, but other estimates have put the figure at 70 million a year, because mental illness can lead to other health problems.

The cost of mental health in Wales is difficult to quantify, but one estimate in 2009 put the cost at £7.2bn, including the cost to the NHS, the impact on the economy and the impact on the quality of individuals' lives.

Prof Keith Whitfield, from Cardiff Business School, said as well as affecting individuals and their families, poor mental health was also holding back the economy.

"There is a case that part of the productivity issue that is facing the UK economy is down to the fact we are not addressing mental health issues as well as we should be," he said.

Image caption Mental health "first aider" Julie Timothy looks out for construction workers who may be struggling

In the building trade, minds are focusing on this - Mates in Mind is a charity dedicated to the issue in construction.

Its executive director Joscelyne Shaw encourages people at work to look out for changes in work colleagues' behaviour, for instance whether they may seem irritable or have sweats.

"It's overcoming the isolation. Reaching out to each other," she said.

At Bouygues one of the people reaching out is mental health "first aider" Julie Timothy, who looks out for changes in employees' usual behaviour.

"I just literally ask them 'Are you OK?' A lot of the time people say, 'actually, I'm not'."

If you are struggling to cope, you can call Samaritans free on 116 123 (UK and Ireland) or visit the BBC Action Line website.

You can also contact the Community Advice and Listening Line for Wales, which offers a free confidential support service with help to find local mental health services, on 0800 132 737 or text 'Help' to 81066.