SLIPPERY ROCK — Several law firms representing the Slippery Rock School District filed a class-action lawsuit in federal court Tuesday alleging that three Ohio-based companies have been knowingly selling defective roofing systems.

The complaint lists Tremco of Beachwood, Ohio, Weatherproofing Technologies of Beachwood, Ohio, and RPM International of Medina, Ohio, as defendants.

“Tremco knew since mid-2005 that its BURmastic roofing systems, which were installed over insulation board, had a strong potential to fail, and that many of these installed systems were, indeed, failing,” the lawsuit complaint reads.

The district entered into contracts with the defendants to have roofing installed at Slippery Rock High School and Moraine Elementary School.

School district officials could not be reached for comment.

Other potential plaintiffs would include residences, school districts, hospitals, post offices, manufacturing facilities and other businesses around the county that also dealt with Tremco in recent years.

The law firms on the complaint are: Robert Peirce and Associates of Pittsburgh; Medure Bonner Bellissimo Peirce and Daley of New Castle; Carpenter and Schumacher of Plano, Texas; and Bellissimo and Peirce of New Castle.

The complaint does not specify the amount of damages that the district will seek, but it does list the total amount of damages for the full class as more than $5 million. The case was filed in U.S. District Court in Pittsburgh.

The sale of defective products is identified in the claim as negligence, fraud, breach of contract, breach of express warranty and breach of implied warranty.

But that is not the only wrongdoing the suit alleges.

It also claims that the companies committed fraud by misrepresenting their products. The defendants sold products labeled as “premium” that were equal in composition to less expensive products labeled as “generic” or “economy,” according to the suit.

It also accuses Tremco of collusion and overcharging, saying that it created an “environment of unfair bidding practices that favored contractors and third parties with whom Tremco already negotiated certain deals for products and services.”

A Tremco spokesman said Friday in an e-mail that the company will aggressively defend against any allegations.

“We have not received service of that lawsuit from the claimant, but are confident that the negative allegations you mention regarding our products or pricing are based upon inaccurate information,” he said.

Since the suit alleges that the defendants violated the Pennsylvania Unfair Trade Practices and Consumer Protection Law, there could be a class of plaintiffs from Pennsylvania and a class of plaintiffs from any state.

If the suit proceeds as a class-action suit, a judge would determine a timeline and procedure for plaintiffs to opt out of participation.