CertainTeed Gypsum, Inc. v. Pacific Coast Building Products, Inc.

Background

CertainTeed brought the case seeking declarations that two patents owned by Pacific Coast Building Products, Inc. were unenforceable because of inequitable conduct and that CertainTeed had not infringed them. Pacific Coast and PABCO Building Products, LLC counterclaimed that CertainTeed’s SilentFX QuickCut product infringed at least one claim of each patent. CertainTeed later counterclaimed that the asserted patent claims were invalid for lack of nonobviousness.

The patents concern laminated gypsum-board structures and methods for making them. The disputed terms, “inner surface” and “inner unclad surface,” appear in asserted claims of U.S. Patent Nos. 10,125,492 and 10,132,076. The court also considered the defendants’ request to correct a typographical error in claim 1 of the ’076 patent, which referred to a “method of foiling.”

Parties’ Positions

CertainTeed proposed giving the disputed terms their plain and ordinary meaning. The defendants proposed defining both terms as “the interior surface not covered by edge cladding.” The defendants argued that a skilled person would understand “inner surface” to refer only to the portion of the inner face not covered by paper that wraps around the board’s edges.

The court examined the claim language, the patents’ descriptions and figures, the prosecution history, and expert evidence. It concluded that the defendants’ proposed definition would make the claim requirement that the “entire inner surface” be unclad lose much of its meaning. The court also relied on statements the defendants made during patent prosecution describing a special manufacturing process that produces inner unclad surfaces, rather than simply combining traditional gypsum boards.

Rulings

The court construed “inner surface” to mean “inner face” and “inner unclad surface” to mean “inner unclad face.” In practical terms, the construction treats the inner face—not merely a smaller region left uncovered by supposed edge cladding—as the relevant surface, so the claim’s requirement that the entire inner surface be unclad retains meaning.

The court also granted the defendants’ request for judicial correction of claim 1 of the ’076 patent, changing “method of foiling” to “method of forming.” CertainTeed did not dispute that the error was obvious or that “foiling” should read “forming,” but argued that the court should not permit retroactive damages for the period when the claim contained the erroneous wording. CertainTeed conceded that the court did not need to decide that issue at this stage.

Judge Lucy Koh issued the order on September 16, 2021. This order construed patent terms and corrected claim language; it did not decide the parties’ ultimate infringement, unenforceability, or invalidity claims.