Mr Every said his chief executive Mike Kane knew what he was getting into when he threw the construction materials company into its massive legal battle with the union.

The public scrap started 20 months ago after Boral refused to give in to the CFMEU's demands to starve developer Grocon of concrete in the Melbourne CBD.

Boral estimates it has lost $10 million in earnings and legal fees as Kane has taken the fight through the courts, the Australian Competition and Consumer Commission, Fair Work Australia and most recently at the Royal Commission into Trade Union Governance and Corruption.

Dr Every, who also chairs the Wesfarmers conglomerate, said Kane won't back down.

"There's a steely resolve in Mike to see this through. Mike's clarity, tenacity and courage on this particular topic is outstanding. He's shown great leadership and when I move around in my business circles in Australia there's nothing but admiration for Mike," he said.

"It's great to be on record to say that myself as chairman and the board are unanimously in support of what Mike is doing. We've been that way since day one."

Little over a week ago counsel assisting the royal commission, Jeremy Stoljar SC, released 1000 pages of initial findings and recommendations, concluding that "a number of officials of the CFMEU seek to conduct their affairs with a ­deliberate and disturbing disregard for the rule of law".

Dr Every said Boral's market share in the Melbourne CBD has gone from 40 per cent to less than 10 per cent due to the union's secondary boycott on the company. He's "delighted" with Mr Stoljar's report.

"It's unlawful what's going on. He [Mike Kane] is outraged by it and rightly so. He's been dismayed with the lack of pace. It's been going for two years without action being taken to remedy the situation," he said.

The Boral chairman also poured cold water on analyst expectations that the company is gearing up to make an acquisition in the United States.

Mr Kane said at the company's August result that he wants to diversify away from Australia where Boral currently derives around 80 per cent of its revenue.

Mr Kane - who has publicly said acquisitions are on the table - wants to generate 50 per cent of revenue from Australia, 25 per cent from Asia and 25 per cent from the US.

But Dr Every said analysts had overcooked his CEO's comments.

"The board, including Mike, don't feel any pressure to grow. As the cycle in the US comes back, if there are opportunities in some areas to form JVs or optimise our returns we would consider them but we do not feel compelled to go out and make an acquisition to balance the portfolio," he said.

"The risk bar is pretty high and we won't be jumping into acquisitions with any speed. There's nothing in front of the board now."

The Boral board has been criticised by analysts and investors for overpaying in its Lafarge and Wagners deals.