For most walls less than 4 feet tall that have no additional loading behind them, soil reinforcement is not necessary. For walls taller than 4 feet, or walls supporting additional loading, you should consult with your local building officials and a licensed professional civil engineer, if required, to determine whether soil reinforcement will be needed. This is important, because improperly engineered walls, or walls with insufficient soil reinforcement, could fail.
Check your geogrid manufacturers’ instructions for installation specifications. The type, length and spacing of the geogrid will vary for each project and should be specified in a final wall design prepared by a licensed engineer.
Lay the geogrid on top of the units starting about 1 inch behind the front face of the wall. Roll it out behind the wall and over the compacted drainage aggregate and backfill. Cut to the length specified in your construction drawings.
Position additional pieces of geogrid adjacent to one another without overlapping. Then, place the next course of units on top of the geogrid. Insert pins to secure the geogrid between the two courses. Remove the slack by pulling the geogrid away from the wall face and anchoring the back ends with stakes in each corner.
When all the geogrid sections are in place and staked tight, place drainage aggregate and backfill and compact both.
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