What type of base does my tank need to sit on?
The foundation that your tank sits on is critical to ensure that it is supported adequately without the risk of causing fatigue to the tank and potential failure. To correctly install your rainwater tank, it must be placed on a firm, level and flat base, free from any rocks, stones and sharp edges. A concrete pad is recommended, however, a compacted sand base or other consolidated fill such as crusher dust is also suitable.
The base must be thoroughly compacted and be exactly level and flat in all directions and should be 75-100mm deep and at least 600mm larger in diameter than the tank base. The outsides of the base must be supported by a retaining wall of some kind to ensure that no erosion can occur through washout, vermin or any other factor. Failure to provide a stable base will void the warranty. It is important to check the base on an annual basis to ensure it hasn’t eroded, as this may affect the structure of the tanks.
If the foundation is not concrete, it’s ideal to have a roof structure over the tank for drainage – Consult the Installation and Operation Manual of the manufacturer for more details.
If you have a chemical tank the slab needs to be engineered to support the weight of the tank without flexing or breaking.