Masonite fell deeper into the red during the fourth quarter with a $778,000 loss after posting a $20,000 loss during the same period a year ago, the company announced today. The results come despite a 14% increase in sales to $383.8 million for the period ended Dec. 31.

Net sales at the Tampa, Fla.-based residential and commercial door manufacturer’s North American unit also jumped 18.5% to $267.6 million.

Total company gross profits for the fourth quarter increased to $49.6 million, a 34% growth over 2010’s results. Selling, general and administrative expenses for the period increased by $7 million to hit $47.7 million. Earnings before income, taxes, depreciation and amortization (EBITDA) increased 34% to $22.3 million. Fourth-quarter results were affected by a $6.1 million interest expense, compared to a $6,000 interest benefit last year.

“We generated strong top and bottom line growth in the quarter achieved by the base business and acquisitions,” said company President and CEO Fred Lynch in a statement. He credited the company’s focus on improving its operations and controlling costs on its base business as well as the acquisition and integration of Marshfield Door Systems and door facing manufacturer Birchwood Best, both U.S.-based.

For the year, the North American segment saw a 6% net sales increase from 2010 to surpass $1 billion with results driven by incremental sales from acquisitions and partially offset by lower unit volumes and price mix.

Annual adjusted EBITDA for the entire company grew less than 2% from a year ago to $82 million. Sales increased 8% to $1.5 billion over 2010, achieved in part by changes to product pricing including customer, product and geographic mix. Annual gross profit increased 3% to $185.4 million.