INSTALLATION | Keystone 133Elite Units
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STEP FOUR: Backfill.
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| Once the pins have been installed, provide 1/2”- 3/4” (10 - 20mm) clean crushed stone drainage fill behind the units to a minimum depth of 12” (300mm). Fill open spaces between units and in the “tails” of the units with the same drainage material. Proceed to place backfill (free draining granular fill) in maximum 6” (150mm) layers. Compact to 95% Standard Proctor density with the appropriate compaction equipment. |
