Ply Gem doubled its bottom line from a year ago to post a $5.2 million gain in the second quarter as sales rose 4.3% to $307 million for the same period, the company announced Friday. The sales growth rate is a steep drop from the first-quarter’s 19.5% gain over the previous year, leading the company to credit this quarter's lagging growth to a warmer-than-usual winter which spurred activity in the construction and remodeling sector.

The Cary, N.C.-based exterior building products manufacturer reported adjusted EBITDA at $44 million, up from $42 million a year ago and a gain on the first quarter 2012’s adjusted $14 million in EBITDA; the company posted a $25 million net loss for the quarter.

The company defines adjusted EBITDA as net income (loss) plus interest expense (net of interest income), provision (benefit) for income taxes, depreciation and amortization, non-cash foreign currency gain/(loss), customer inventory buybacks, restructuring and integration costs, write-off of previously capitalized offering costs, environmental remediation, and gain (loss) on modification or extinguishment of debt.

Factoring in the inventory buyback expense from new customer wins, the company reported that second quarter operating earnings grew slightly to $31 million from $28.8 million a year ago. Gross margins grew to 23.8% in the second quarter from 22.7% a year ago.