How much water can I collect from my roof?

The amount of rainwater you can collect is dependant on three critical factors:

  • Average annual rainfall for your location – The Bureau of Meteorology website www.bom.gov.au/climate/averages is a great place to find the annual rainfall for your area
  • The roof surface area supplying rainwater to your tank – Measuring the external dimensions of your home will give you a reasonable approximation
  • The number of down pipes connected to your tank – and the percentage of roof area they will deliver. The formula to bear in mind when calculating how much water you can collect is this; One millimetre of rain falling on one square metre of roof (1m x 1m) will collect one litre of water. Remember, you don’t need to purchase a tank with a capacity equivalent to the total annual rainfall as you will gain the most benefit from your tank by constantly using the water and topping it up when it rains.

 

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How do I install my Nylex tank?

Once you have decided on the right tank for your needs, you can take a lot of the stress away from setting it up with a bit of planning and the answers to some simple questions. For example:


  1. What type of base your tank will sit on – e.g.; concrete, sand or on a stand?
  2. How are you going to connect it to the roof – e.g.; how many down pipes will supply the tank, types of filters, first flush devices etc.?
  3. How are you going to deal with the overflow – e.g.; connection to the storm water drain?
  4. What sort of attachments (pumps, hoses etc.) will you be connecting to your tank for use?

Your Nylex dealer or local plumber are good sources of information and can also help out with the project.

In fact Nylex recommend your tank is installed by a suitably qualified plumber. This ensures the work complies with the relevant building regulations and that you are eligible for any Government water rebates applicable to your location.

In Addition:

  • The site must be level and free of rocks, stones and sharp objects
  • The tank should not be buried more than one third of its wall height
  • Ensure that the tank base is at least 600mm larger in diameter than the tank
    • Sand Base: A 75-100mm bed of level packing sand can be used as a base for your tank. The sand will need to be well compacted and contained to avoid any under tank erosion from wind, water, burrowing animals etc..
    • Tank Stand: The tank can only be mounted on a stand that has been certified as capable of supporting the weight of the tank when full – all Nylex tank stands are certified. The site must include an appropriate foundation and you may require building approval for tank stands over 1,000L. Rainwater tanks can be positioned on a number of different bases: Concrete Base (preferred): A minimum 100mm, level and smooth finished concrete slab will provide an excellent base
  • A length of flexible pipe (at least 300mm long) should be installed after the ball or gate valve to absorb any shocks or movement generated by the delivery system
  • Make sure all pipes are well supported and do not depend on the tank for support
  • To avoid undermining the base, the tank overflow should be run well away from the tank
  • Inlet and overflow pipes should be of the same diameter to prevent water overflowing through the strainer.

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What do I need to do before my Nylex tank is delivered?

  • Nylex delivery vehicles can exceed 19 metres in length – check to make sure there is sufficient room for the truck to manoeuvre
  • Nylex drivers will make every effort to unload your tank as near as possible to the tank’s final location
  • If you need to lift the tank over obstructions, you will need to organise a crane and have it on site during delivery
  • DownUnda tanks require a crane for delivery and installation
  • Nylex provide a driver only so you will need 1 additional person for tanks up to 13,500 litres, 2 people for tanks from 13,500 – 22,700 litres and 3 people for tanks greater than 22,700 litres
  • Once the tank has been delivered it is important that you secure it immediately to prevent injury – tie it down with rope or wire or add water as ballast.

PLEASE NOTE: Given the size of rainwater tanks and the length of our delivery truck and trailer combinations, Nylex is governed by strict Over Dimensional Load regulations. Therefore delivery restrictions and charges may apply depending on the size of the tank and your location. Customers in remote locations should confirm the availability and cost of deliveries when placing a tank order. Your Nylex dealer will be able to provide you with these details.

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How big should my Nylex tank be?

It really depends on what you want to use the tank for and how much space you have for a tank. As a rule of thumb, choose the largest tank for the space available. If you are planning to put it by the side of the house or in a small backyard, a Nylex Slimline tank may be more suitable.

Measure the available width, length and height of the space and make sure the tank will not obstruct doorways, windows, eaves, external air conditioners, tree trunks or other obstacles.

Once you have calculated the available area, use the tank chart on the next page to select the right Nylex tank for your needs.

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