Owens Corning posted net income of $51 million in the third quarter of 2013 on net sales of $1.32 billion for the quarter, compared to net income of $44 million on sales of $1.28 billion in the year-ago quarter.

In the company’s building materials division, roofing logged $471 million in third quarter net sales, the same volume as in the third of 2012, while insulation brought in $431 million in net sales in the quarter compared to $384 million in the year-ago quarter.

Earnings before income taxes (EBIT) for roofing came to $96 million in the third quarter, compared to $83 million a year ago. EBIT for insulation totaled $18 million in the quarter, versus $3 million in third quarter 2012.

Composites posted $453 million in net sales, down slightly from same quarter 2012 net sales of $459 million. Composites EBIT were $21 million in the third quarter, compared to $11 million in the year-ago period.

“Our roofing business sustained strong margin performance,” chairman and CEO Mike Thaman told investors during the company’s third quarter earnings call.

“The insulation business delivered its best quarter in six years, and is profitable year-to-date,” he said. “And composites improved EBIT by $10 million compared to last year. The company delivered $119 million in adjusted EBIT, an increase of $38 million from the third quarter of last year.”

The roofing segment delivered 20% margins, a 2-point increase year-over-year, sustaining the margin improvement the company reported in the first half of the year.

The continued improvement in the U.S. housing market helped the insulation business which delivered its best quarter in six years and will achieve full year profit in 2013.

Thaman said that while composites improved third quarter EBIT by $10 million compared with last year, on a sequential basis, EBIT was down $11 million.