Boral's board has incurred a first "strike" with a heavy vote against its remuneration report as the building materials company also warned significant wet weather has hurt business activity in recent months.

Shareholders delivered the company a first strike at its annual general meeting in Sydney on Thursday, with 26.1 per cent of votes cast against the executive pay report.

Boral chairman Brian Clark said the company had tried to explain the rationale behind its remuneration report to investors ahead of the meeting and would take the feedback it had received on board.

Chief executive Mike Kane said wet weather across the nation and unexpectedly slow sales in Western Australia would take a toll on first-half earnings, sparking a fall in Boral shares.

“Unfortunately, there has been significantly more wet weather across the country compared to seasonal averages and this has had an impact on our business, at least in the short-term,” Mr Kane told investors at the AGM.

“In Australia we are behind where we thought we would be at the end of the first quarter, primarily because of wet weather and lower volumes in Western Australia.

While a downturn in South Australian sales was in line with expectation, Boral did not predict such weak demand out of WA, due to a lack of major projects, Mr Kane said.

“The Western Australian market has come off a little harder than we thought it would,” he said.

The company now plans to cut back production at its Midland Brick operation in Perth even further after it mothballed one of its kilns late last financial year.

On Boral’s US business, Mr Kane said despite fewer than expected housing starts in the first quarter, the company still expected earnings to grow for the full year.

Mr Kane said Boral Australia could be expected to deliver slightly higher full-year earnings in 2016/17 compared to the previous year if weather patterns returned to normal.

Housing activity strength and and an uplift in major infrastructure projects on the east coast are expected to boost the company’s second half results