When installing the tank, there are two types of backfill to consider: pea shingle and granular backfill. Pea shingle, with a size of 8 to 16 millimetres, is commonly used and provides good compaction without voids. In the UK, 10 to 20 millimetres is acceptable. Granular backfill is suitable if you have well-draining soil and offers more flexibility in the installation process. Another option is a lean dry mix concrete backfill, which is recommended for challenging soil conditions. The excavation size should allow for working room around the tank, typically 250 to 500 millimetres. If you need advice on available backfill materials in your area, we’re here to help. Stone is preferable, but concrete is also a suitable option if necessary.
Posted by Callum Vallance-Poole, on July 10, 2024.
