TUSCUMBIA - Firestone Building Products announced today plans to add about 40 jobs to its Tuscumbia plant as part of a $40 million expansion that will more than double the size of the existing plant.

Construction will begin in the second week of September and completion is slated for the second quarter of 2013, company officials said. Plans call for an additional manufacturing line for the company’s Thermoplastic Olefin roof-sheeting product by July 1, 2015.

Firestone Building Products President Tim Dunn said the company looked at various sites across the nation, but the local workforce and business-friendly environment in the Shoals and Alabama made them decide on the Tuscumbia plant.

“Expansion to the Firestone Shoals plant will allow us to gain some much-needed warehouse space for the short term and increase our manufacturing capabilities to meet customer demand in the future,” Dunn said. “Firestone has been part of the Shoals community since 2006, and we are happy to continue that relationship and grow our business. The state of Alabama and the local community offered us a competitive package that made this a good investment.”

Firestone leases its 104,000-square-foot plant at 393 Denton Circle from the Shoals Economic Development Authority.

The plant has 54 employees, SEDA President Forrest Wright said.

The SEDA board agreed last week to provide $8.75 million toward the expansion if Firestone selected the Shoals.