Fill Sand
Also known as: utility sand, bedding sand, backfill sand
Fill sand is an economical, often unwashed sand used for backfilling, raising grade, bedding pipes and filling large voids. It is a bulk, utility-grade sand rather than a finish material.
In simple terms
Fill sand is the inexpensive sand you use to fill space — backfilling a trench, leveling a low spot or bedding a pipe. It does the structural job without the cost of washed finish sand.
In depth
Fill sand may contain some silt and a mix of particle sizes because it is not washed to a finish spec, which keeps it affordable for high-volume jobs. It compacts reasonably for backfill and sub-grade leveling and is commonly specified by utilities (for example as PG&E trench backfill or pipe bedding). It is not intended for concrete mixes or smooth finish surfaces, where washed concrete or mason sand is required.
Why it matters
Fill sand keeps large-volume jobs affordable — using premium washed sand for backfill or grade-raising would waste money on material that is buried out of sight.
Common mistakes
- Using unwashed fill sand where a clean, washed sand is specified (concrete, finish bedding).
- Assuming all fill sand compacts equally — confirm suitability for load-bearing backfill.
Examples & uses
- Trench and utility backfill.
- Raising or leveling low areas of grade.
- Pipe and conduit bedding.