They might look rough and ready but construction sites are among Australia’s most caring places to work.

That’s according to a major national survey conducted by the mental health charity beyondblue.

It found construction workers are the most likely to say they work in a mentally healthy environment.

The least likely are agriculture and public administration workers.

Geographically, workplaces in Western Australia are the most mentally healthy and those in Queensland the least.

The research was released on Monday to mark the launch of headsup.org.au, a free online guide businesses can use to create their own mental health plan.

It also also found that around 50 per cent of employees do not believe they work in a mentally healthy environment and one in five had taken time off work in the past 12 months because they felt mentally unwell.

Supportive and caring managers and flexible working hours are important attributes of a mentally healthy workplace, according to beyondblue.

These organisations also encourage workers to take lunch breaks, prevent discrimination and have support programs.

Many employers don’t realise they can reduce absenteeism and improve productivity by improving mental health, says beyondblue Chairman Jeff Kennett.

“Employers not only have a health and safety obligation to deliver good mental health in the workplace but also a moral obligation to support their workers who often spend more time at work than anywhere else.”

He said the online guide could help businesses of all sizes with practical guidance on how to set up a mental health plan.