Construction material costs continued to increase in January, even as the amount contractors charge for completed projects remains flat, according the Associated General Contractors of America.

Prices for materials used in construction jumped 0.9 percent in January compared to December and 4.9 percent compared to January 2010, according to a statement. Construction costs also outstripped the producer price index for finished goods, which rose 0.8 percent month-to-month and 3.6 percent year-over-year.

"The last thing contractors need after two years of depression-like conditions is to pay more to make less," said Ken Simonson, the association’s chief economist. "With margins continuing to shrink, few contractors are likely to benefit even if construction demand picks up this year."

Prices rose by double-digit rates over the last year for five construction materials: diesel fuel prices by 17.7 percent; steel mill products by 11.5 percent; hot rolled boars, plates and structural shapes by 14.3 percent; steel pipe and tube rose by 17.8 percent; and prefabricated metal buildings by 12 percent.