Memorial Stadium, Baltimore, MD Product Selection and Testing All products and materials used in the design and construction of a SportGrass athletic field are subjected to rigorous testing prior to installation to ensure conformance with the specifications and guarantee optimal performance under actual conditions. Gravel Drainage Layer USGA specifications are followed with respect to a gravel layer to achieve the desired bridging factor between the selected sand medium and the gravel and, of course, to rapidly facilitate water movement from the sand rootzone into the sub drainage system below. An additional benefit is derived from the creation of a perched water table which is an integral factor in soil moisture management. Sub Drainage System / Automatic Irrigation The sub drainage system is critical to the performance of a natural grass athletic field. SportGrass Inc. custom designs sub drainage systems for each installation depending upon local climatic conditions, rootzone composition and other site specific considerations. Typically, 4" to 8" drain laterals are spaced on 15' to 20' centers on a 1% slope and tied into a main collector ranging from 12" to 24" which is connected to the site's storm water management system. SportGrass fields incorporate fully automatic irrigation systems and use only components that have a demonstrated record of performance and reliability in athletic field applications. Sand Based Rootzone Standard practice is to use a 100% sand base with organic material added to aid in moisture and nutrient retention. The addition of excessive clays and silts is something that will inhibit the drainage characteristics and is not recommended. SportGrass Inc. uses USGA specifications as a rootzone guideline for the selection and testing of the sands and gravel, but minor deviations are sometimes required to accommodate the specialized needs of athletic fields. Final Grading The finished subgrade, prior to the installation of SportGrass, is laser graded to demanding tolerances and can be constructed either perfectly flat or with a slight crown, depending on the desires of the customer and the anticipated use of the field. SportGrass Installation The SportGrass synthetic turf material is manufactured in 15' wide rolls that are typically 100' long. The material is laid on top of the laser graded sand-based rootzone, the seams are either stapled or sewn, and additional sand, matching the subgrade sand, is blown or topdressed into the fibers. For a full field installation this typically takes about 5 to 7 days. After sanding, grass seed or sprigs are applied into the SportGrass fibers and then fertilizer is applied and the field is usually ready for play 14 to 16 weeks after seeding or 10 to 12 weeks after sprigging.

For more information