5 Best Stones for Backfill
Construction projects typically require a vast amount of digging and these holes will eventually need to be filled. Backfill refers to the material used to refill an excavated hole, and it is typically used to strengthen and support a structure’s foundation while also promoting better water drainage.
Stone is a great choice for backfill because it’s durable and offers great drainage; however, some stones work better than others. Explore the five best stones for backfill below.
1. SCREENINGS
Screenings, otherwise known as FA5 or limestone screenings, are a great choice for backfill because it compacts well. Because of this, screenings are most often used for pipe and sewer backfill, or as a base for brick pavers.
2. TRENCH BACKFILL (TBF)
Trench backfill is somewhat similar to CA6/Grade 8, but may have smaller pieces of aggregate. It compacts very well and can be used for a variety of fill projects. It also provides some drainage characteristics.
3. CA7 BEDDING STONE
CA7, otherwise known as ¾” limestone, or sometimes as 1” limestone, and commonly referred to as “bedding stone”, is an angular white/gray stone that self-compacts, making it ideal for use in backfill as well as pipe bedding, subbase and drainage situations. This is one of the most popular backfill products specified in underground construction projects.
4. CA6/CM06/GRADE 8
CA6 is often referred to as subbase granular backfill because it’s regularly used as road base or along roadway shoulders. In addition, though, this material is great for backfill on projects.
5. 3″ STONE
Some projects that require larger quantities of material—filing a bigger hole—may choose to start with 3” stone for the first layer of material. 3” stone fills in large areas, leaving some voids, while providing excellent drainage characteristics. It is then often covered with a top layer of CA6 to provide additional fill and compaction. In addition to backfill, this material works well for soft subbase applications and road base.
When your project requires backfill, be sure to choose the materials experts to help supply you with the right material. Contact an Ozinga materials specialist today.
