Cambridge Elementary School

Larson Engineering, Inc. provided project evaluation, construction cost estimating, drainage and safety design, developed construction documents, coordinated bidding, and performed construction administration and inspections during construction of the rubber surfacing.

This project consisted of installing rubber surfacing for the playground at the school. The first step was to excavate the existing soil from within the playground area to expose the underlying sandy soils. The depth of excavation also depended on the required rubber surfacing thickness. Specific areas require different thicknesses of rubber surfacing depending on the fall height of the specific playground equipment.  After the subgrade had been graded and compacted, a soil separation fabric was installed. Then 6” of drainage rock and 2” of leveling rock was placed and compacted, to create solid and level base for the rubber surfacing. Next, the base mat of rubber was placed to ½” from finished grade, and then the top coat of rubber was placed around the entire playground at ½” thick. The top coat of rubber can be chosen from a variety of different colors. The Cambridge-Isanti School District selected blue to match the school’s color. The top coat of rubber was a 50/50 blend of blue and black rubber.