Join ESCSI and Become A Member


ESCSI is the unified voice of the expanded shale, expanded clay and expanded slate industry. ESCSI members include companies, firms and organizations working together for the betterment of the lightweight aggregate industry.

Producer Membership

ESCSI offers Producer membership to firms or individuals producing and shipping lightweight aggregates consistently conforming to the current version of Specifications C-330 and C-331 of the American Society for Testing and Materials (ASTM). Such lightweight aggregates shall be produced by expanding and vitrifying suitable shale, clay and slate by the rotary kiln process.

Associate Membership

ESCSI offers Associate membership to companies, individuals or organizations that promote or support services to the expanded shale, clay or slate members. Industry associations that support ESCS and whose members include ESCS manufacturers, distributors and suppliers may join as Associate members. Companies or associations that produce or promote alternative products for uses similar to uses of expanded shale, clay or slate are not eligible for Associate membership.

Member Benefits:

  • Annual Technical and Process Technology Midyear meeting where members come together to discuss industry-wide issues, help identify new programs, exchange ideas and help shape the future of the industry
  • Newsletter contribution opportunities – the industry’s only dedicated publication for the latest news, applications, case studies and information on the lightweight aggregate industry
  • Online directory of members and their production locations with links to their own company websites
  • Committees that work to monitor codes and address technical issues that affect our members
  • Website ( that keeps our members up-to-date on industry issues and serves as the leading resource for information on the lightweight aggregate industry and its applications.