Sand is a key component of a properly backfilled hole or trench in that it provides drainage and compacts well, especially when damp. Backfilling specifications are different, depending on your county's codes, but will generally include a layer of aggregate rock used as bedding around pipes and underground infrastructure. Above the rock bedding is a layer of felt to prevent the sand from washing into the rock bed, sand and top soil. Properly layering these materials prevents sinking after the backfill.
Things You'll Need
- ¾-inch aggregate rock
- Felt fabric
- Utility knife
- Compaction machine
- Measuring tape
- Water source
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Send the measuring tape vertically into the hole or trench to determine the depth. Divide this number by two to determine the depth of the rock and sand to complete the backfill.
Shovel the aggregate rock into the hole or trench, up to the height determined by your measurement.
Spread a layer of felt fabric over the entire surface area of the rock, cutting it along the edges of the hole or trench with a utility knife.
Fill sand onto the felt, completely filling the trench. Spray the sand with water and compact it using the machine according to manufacturer's directions. Continue to wet the sand as it compacts. Once the compaction becomes minimal, that is the compactor does not sink over the sand, fill the remaining hole or trench with local topsoil.