College of Architecture and Environmental Design


Construction Management Department

Degree Name

BS in Construction Management




Thomas Kommer, Phil Barlow


This paper is a case study that identifies why Geofoam was used as in-fill material for a construction project located at a high school in Encinitas, CA. The Geofoam was installed under a stairway that connects to a structural retaining wall. The concrete formwork was connected directly to the foam and the stairs were poured in place onsite. The foam acted as the on-grade material, so the concrete stairs did not have to be self-supporting. The purpose of this study is to understand the benefits of using Geofoam, as the in-fill material, as opposed to other traditional materials. An analysis of various factors, given by the structural engineer, architect, inspector, and superintendent involved in this project, was conducted to compare alternate materials. The Geofoam was used because it alleviated concerns about cost, weight, limited access, and time. The material had neither positive nor negative effects on cost and environmental concerns.