Site Preparation

  1. Tank site must be level and free of any rocks, stones or foreign objects that may damage the base of tank.
  2. Site must be solid. If fill is to be used, ensure tank site is well compacted.
  3. Tanks can be positioned on 75-100mm of level bedding sand, crusher dust or FCR, a level concrete slab or a sturdy tank stand. Small blue metal or roadbase (less than 10mm stone) is suitable, but larger stone is not recommended as it may contain sharp stones capable of damaging the base of the tank.
  4. Tank pads should be at least 300mm greater in diameter than the base of the tank.
  5. Tank pads must be adequately retained to avoid any under tank erosion from water, wind or vermin.
  6. Concrete slabs must be smooth finished and of sufficient thickness and suitably reinforced to support the weight of the tank when full.
  7. Tank stands should have hardwood decking spaced no greater than 50mm apart.
  8. Bearers must have sufficient strength to prevent deflection when tank is full.
  9. The tank should not be buried greater than one third of its wall height. If tank is to be buried, fill with water prior to back-filling, and back-fill with clean sand only. Water level in tank to remain at or above ground level at all times.
  10. Tank overflow must be piped well away from the tank to avoid undermining the base.
  11. In all installations, make sure outlet pipes are joined to the tank outlet fitting with a flexible coupling or pipe and properly supported, not depending on the tank itself for stability.

Note: Incorrect site preparation or installation may void your warranty.

Additional Information (Courtesy of the Association of Rotational Moulders Australasia Inc - ARMA):

If you are installing the tank yourself it's vital that you carefully read the manufacturers installation and maintenance instructions.

A tank full of water is extremely heavy and a poorly maintained base under a poly tank can result in it failing and needing repair - which won't be covered under your manufacturers warranty. Correct preparation will result in years of trouble-free performance from your tank. If in doubt, involve a specialist.

All water tanks can slowly build up a layer of sludge in the bottom.

This is caused by dust and debris entering the tank which will happen no matter how effective your filtering system is. As a general rule check your tank for sludge every two to three years. However, in Metropolitan areas there are other factors that need to be considered to ensure that the rainwater you harvest can be used to its full potential. For example; your roof is more likely to collect heavy metals from the pollution in the air so first flush devices, sieves and gutter maintenance are vital.

No matter how tough your tank is, it may at some time receive an unexpected impact.

It is important that damaged tank plastic is repaired by qualified and experienced contractors to ensure your tank remains safe and watertight. Ask your agent or manufacturer for a recommended repairer. You may have seen claims that whole industries have appeared to repair tanks. Whilst accidents sometimes occur - vehicles may back into them, sometimes they are badly installed and occasionally manufacturing flaws need to be repaired - the same is true for all tank material. Plastic welding companies don't fill their days crossing the country repairing water tanks. However, they do provide excellent repair and fabrication services when required.