This office building project in Westlake, Louisiana used 340 blocks of EPS15 Geofoam 23 inches x 4 feet x 8 feet to form a grade beam foundation system. The 14,350 square foot building, which is at an elevation close to sea level, required an above ground foundation system due to the high water table. EPS blocks are commonly used to form grade beam foundations because of their light weight, high compression strength and ease of installation and cutting. Installation of the blocks and rebar cages for the grade beams can be installed in any order. The majority of the blocks are delivered to the site precut and ready to place. When cutting blocks on site is required, it is easily done with a geofoam hotwire kit which consists of a length of wire, 2 handles and a transformer to heat the wire. The heated wire is guided by two people through the foam block with each person holding one of the handles.
Prior to the concrete installation it is necessary to make sure all of the blocks are secured so they cannot be undermined by the concrete in its semi liquid state. A pump truck is used for the concrete installation, making sure to place concrete on top of the block first for additional ballast, then around the perimeter.
Above ground grade beam foundations are often used in southern Louisiana due to the high water table. Construction can move at a more rapid pace using an above ground grade beam foundation because it eliminates delays caused by dewatering operations.
Expanded polystyrene is used in many construction applications ranging from insulation to form liners to void fill under foundations and highways. It is available nationwide.