Eagle Materials (EXP) said Friday that its American Gypsum unit plans to expand and modernize its gypsum wallboard plant in Duke, Oklahoma.

The estimated $330 million investment will boost the plant's annual wallboard manufacturing capacity by 25% and cut operating costs by almost 20%, the company said.

Eagle Materials said planning has been completed and all regulatory approvals have been received for the project, with construction expected to start immediately and startup set for H2 of 2027.