Boral has identified a new strategic model and has announced its plans of raising $490 million to support investment and reinforce its balance sheet.

Boral, the construction materials firm, said its strategic examination had clearly flagged the priorities for core investment of the company, which includes construction materials and cement in Australia, plasterboard in Asia and Australia, and roof tiles, masonry, and bricks in Australia and in the US.

"The actions taken from the strategic review provide a strong platform for increased growth and earnings when external conditions improve," Mark Selway, CEO of Boral said.

As part of the renewed strategy, Boral will initiate a takeover of the 50 per cent remaining shares of MonierLifetile, its concrete roof tile arm in the US, for $89.5 million ($US75 million), and shell out $280 million into primary Australian assets to strengthen its position in the markets of Victoria and New South Wales.

It will support the development through its accelerated and renounceable 1-for-5 entitlement offer, fully underwritten, which is being tendered at $4.10 per share issue price, giving about a 16 per cent discount to Boral's previous issued price of $4.89 per share.

After a strategic re-examination, the Sydney-based construction materials firm said that it will also take impairment charges worth $289 million as it closes several inefficient and obsolete factories.

Boral said that with the impairment charges excluded, its annual profit is projected to post from $123.5 million to $132 million. Boral had earlier pointed out that its net profit would post as expected in the market forecast amounting to $123.5 million.