Permeable Cellular Concrete: Private Project, Seattle, WA

This job site was a challenge because it was over 45′ below ground level. Many obstacles were prevented using typical fill materials. It was in a busy area of town limited on each side by buildings and street access. Below the slab-on-grade, a drainage layer was needed. The typical conveyor system and truckload after truckload of material was considered infeasible due to the depth and schedule concerns of the pour area. The flowable nature of low-density cellular concrete (LDCC) was suggested as a value alternate to speed the construction process and assist in the drainage below the slab.

Cell-Crete was hired to pour permeable cellular concrete in four separate areas for a total of 1,800 cubic units (CY). Permeable cellular concrete was suggested as part of the drainage layers below the slab. Anticipated truck deliveries were reduced from 120 to 12. This was a major help in a project demanding trades to work together and accomplish a tight deadline. Cell-Crete set up equipment away from the normal delivery area and strung hoses along the shoring walls to the pour area. A darby finish was placed on top of the LDCC and vapor barrier used to reduce the telegraph cracking through to the slab-on-grade. This was completed in 8 days with 4 separate staging areas.