The cost of construction materials outweighed the prices of finished buildings in April, according to the Associated General Contractors of America (AGC).

The producer price index for all materials increased by 7.1 percent in April year-over year and by 1.4 percent from March, according to a statement. The price of finished buildings rose 1.7 percent or less over the past year and 1.1 percent or less month-to-month in April, depending on building type.

"Contractors have been clobbered for several months by double-digit price hikes for diesel fuel, copper and steel products," said Ken Simonson, the association’s chief economist. "Worse, the price squeeze is hitting many contractors while private demand remains weak, public demand is shrinking and the amount they earn for most publicly funded projects is about to be drastically cut."