Boral, the largest building materials company in Australia, last week warned that conditions in the sector are the worst it's seen for 20 years.
Radio New Zealand's Sydney correspondent says Boral cut its full-year profit forecast for the second time in two months.
Apart from poor economic conditions, the company has been hit by poor weather and delays on major projects.
But it's not just Boral: many companies exposed to commercial construction are suffering, with contractors forced to undercut each other just to stay in business.
Residential construction is also in a slump. Housing starts in New South Wwales plunged 37% in the March quarter to the lowest level since records began nearly 30 years ago.
Further building data is due on Tuesday, as is the Reserve Bank of Australia's monthly decision on interest rates.