Owens Corning (OC) took an axe to its 2012 earnings targets on Tuesday due to trouble for its roofing and composite businesses, marking the second downgrade in just two months for the building products company.

Shares of Owens Corning were hit hard by the downgrade as well as preliminary third-quarter results, dropping more than 7% in premarket trading.

The Toledo, Ohio-based company said it expects to generate adjusted EBIT of $280 million to $310 million in 2012, down from $360 million to $420 million in August.

Owens Corning said the “primary uncertainty” through the end of the year can be attributed to roofing volumes. The company said there was “some improvement” in the third quarter, however “shipments weakened” after prices rose in mid-September and “are not expected to improve for the remainder of the year.”

Due to these developments, Owens Corning said it has lowered its full-year roofing revenue to $2 billion.

Meanwhile, Owens Corning said composites demand has been hurt by lower global industrial production, especially in Europe, and by the weaker U.S. roofing market.

The company cut its estimate for 2012 global glass fiber market demand growth to about 3%, compared with the long-term historical rate of 5%.

For the third quarter, Owens Corning posted preliminary adjusted EBIT of $81 million. Including one-time items, the company said its preliminary EBIT was $59 million.

Owens Corning said it plans to release its full third quarter results on October 24.

Shares of Owens Corning retreated 7.22% to $31.50 ahead of the opening bell. The selloff eats into the shares’ 2012 rally of about 18%.

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