Tomb joins ACA from ACG Advocacy, where she advised clients on housing, energy, infrastructure and federal investment policy. She previously served as CEO of the American Land Title Association, where she expanded the organization’s national visibility and developed partnerships focused on consumer fraud prevention. Her previous leadership roles also include serving as president of the National Rental Home Council and president and CEO of the National Association of Women Business Owners.

Her federal government experience includes leadership positions at the U.S. Department of Housing and Urban Development, the International Trade Administration within the U.S. Department of Commerce and the White House. That background could prove significant as cement manufacturers navigate emissions policy, infrastructure funding, domestic manufacturing initiatives and supply chain resiliency discussions impacting construction materials markets.

“Diane brings strong leadership experience to ACA and a proven ability to advocate effectively on Capitol Hill,” said Monica Manolas, ACA board chair and region president for Ash Grove East. “She has an impressive track record of raising the profile of major trade associations and driving collaboration across industries.”

Tomb said domestic cement production remains critical as data center construction, transportation work and next-generation infrastructure projects accelerate nationwide.

“America’s cement industry is a foundational pillar of our national infrastructure, manufacturing base and national security,” Tomb said. “As innovation and technology reshape how we build, domestic cement production is central to America’s economic competitiveness.”

Tomb will work alongside outgoing ACA President and CEO Mike Ireland during a transition period through the end of 2026. Ireland has led ACA for the past decade during a period marked by increased infrastructure spending, sustainability initiatives and evolving regulatory pressures affecting cement producers and downstream construction markets.

For wall and ceiling contractors, continued federal investment in infrastructure and manufacturing construction could sustain demand for interior finishes work tied to institutional, industrial and commercial projects that rely on cement-intensive structural systems. Contractors will also be watching how ACA leadership approaches energy policy, embodied carbon discussions and domestic material production priorities that could affect project costs and construction timelines.