Untreated fill sand is a natural building material, which is typically sourced from deposits such as riverbeds, quarries, or other natural sources, and used in construction projects to improve the drainage and stability of the soil. Unlike treated fill sand, untreated fill sand has not been processed or modified in any way, and has not been screened for size or consistency. As such, it may contain small pea stone-sized stones, as well as larger chunks of rock and clay.

Untreated fill sand is ideal for use in construction projects, as it can be used to create a solid and durable base for structures. It can also be used to level uneven ground, improve drainage, or backfill trenches, and the landscaping of gardens and parks.

Fill sand and fill dirt are both materials used in construction projects, but they have distinct differences. Fill sand is made up of tiny particles of rock that have been broken down over time. It does not retain moisture and is great for drainage areas, making it suitable for weather exposed projects. On the other hand, fill dirt is composed of organic materials such as clay, silt, and rocks. It retains moisture better than sand and is often used to raise building foundations or reduce the chances of flooding.