Installing Your New Duraplas Water Tank




This page includes details on our:

  1. Above Ground Poly Tank Installation

  2. Underground Lattice™ Tank Installation

  3. An Install Video from a Customer

  4. Reed Bed – Key Information


Above-Ground Poly Tank Installation

Correct Method for Sitting an Above Ground Poly Tank:


The water tank base preparation details outlined below employ the same method for all round design, slimline design and under deck design Duraplas brand poly rainwater tanks.


  1. Your Duraplas poly water tank needs to be sited on LEVEL STABLE GROUND which has UNIFORM COMPACTION (free of soft spots), with a screeding of 75 – 100 mm of metal dust (approx. 3 mm diameter stone). Being a loose aggregate, the metal dust must be retained using a solid form of retaining structure such as cement strips or rectangular treated pine sleepers or round treated pine poles available from most landscaping suppliers, garden nursery’s and hardware stores. Each pad must be oversize to the footprint of the dimensions of the water tank purchased (we recommend a minimum 100mm larger in all directions)above-ground-water-tank-installation-diagram
  2. Alternatively your Duraplas tank can be sited on a reinforced concrete slab which must be 25mpa [approx 75-100mm thick with F72 mesh] that is level, flat and larger than the base of the tank. Consult an engineer for slab details.
  3. It is also best practice to ensure the water tank overflow is plumbed away from the water tank and base, ideally back to existing storm water drainage, or if no such drainage exists, to a designated rubble pit –The overflow water must not be left to simply cascade down the side of the water tank to the base of the tank, where it will likely lead to erosion of the metal dust pad. Any warranty pertaining to your Duraplas water tank will be voided, if this is allowed to occur.
  4. If your water tank is being sited next to the wall of a house, shed or other structure, it is highly recommended that an air gap of at least 50 mm is made available to for air flow, in order to prevent condensation and build-up of moisture.



Correct Method for Sitting Tank Half Way in Ground:


  1. Prepare hole. Ensure that the surrounding soil left in the walls of the hole is solid, leaving a 150 – 200 mm gap to allow positioning the tanks, and back-filling with sand or metal dust, stabilised with cement dust.
  2. If there is major water seepage into the hole from the surrounding soil, the site will not be suitable. Make sure tank site is drained well. Consult your engineer for drainage design.
  3. A base of 75-100 mm of sand or crusher dust (no greater then 3mm stone) must be put in the hole and compacted.
  4. Tank must be lowered into the hole squarely by crane, ensure stainless steel lifting lugs are fitted to the tank and are used to lift (we fit these at factory, upon request, prior to dispatch)
  5. Tank must then be filled with water above ground height, then back filled with bedding sand or metal dust. Cement stabilise this fill medium.
  6. It is important that tanks be buried into ground up to ONLY three quarters (3/4 or 75%) of its wall height. (It is also recommended to use a Heavy Duty grade of tank [HDT] for its extra wall thickness).
  7. It is recommended that your outlet pick up, from the tank, comes through the tank roof, or alternative plumbing from base outlet will be required.
  8. If there are 2 x 90 mm inlets coming into the tank you will require at least 2 x 90 mm overflow pipes.
  9. Overflow water must be piped away from the tank.
  10. Please be aware Duraplas Stresses that all the above steps MUST be adhered and any damage incurred to the tank due to its burial will not be warranted, the above information is to be used as a guideline only. Please seek engineer’s advice if in any doubt as to the suitability of the site.


Note: On Projects where a Tank is required to comply or be certified to AS4766:2020, Partial Burial of your Duraplas Round, Slimline or Under-deck tank may result in compliance or certification of that product to Australia standards (AS4766:2020) being voided.



Using a Tank Stand:


  1. It is recommended that you contact an engineer to ensure that a suitable stand is provided to meet any relevant requirements. Remember every litre of water is 1kg in weight.water-tank-stand-installation-diagram



Be Sure to NOT Make these Errors:


  1. Rocky and uneven ground with little or no base preparation.
  2. Must not have undersized base. The total circumference of the tank must be supported. Ideally, allow the pad to be 100mm wider than the tank.
  3. Wooden sleepers are generally too uneven and untrue to use for base.
  4. Don’t use corrugated iron decking as a base.


Important Points When Plumbing Tanks:

Tank Overflow:


  1. Always ensure that overflow water is plumbed away from the tank. This will reduce site erosion and ensure a sturdy support for the base of your tank. Regularly check the overflow screen and clean when necessary.



2. Underground Tank Installation


    1. Click here to view underground tank installation diagrams (PDF)


      1. Underground Water Tank Installation Video.
        Please use this Video as a reference only complete installation Instructions can be downloaded from the link above.



3. An Install Video from a Happy Customer


Click on the video below to play:





4. Reed Bed Installation – Key information

  • A qualified Plumber is needed for the installation process
  • Excavation for the Reed Bed vessel needs to be 100mm longer, wider and deeper than the vessel
  • 100mm deep of 3mm aggregate in bottom of Excavation
  • Internal Baffles, piping into and out of the vessel to be determined by installing plumber, in line with Government plumbing Regulations & Best practice guidelines.
  • Backfill the outside and the inside of the vessel in alternate section of 200mm Depth to avoid distortion of the vessel.

Reed Bed Resources:






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  • "Thank you for your service & prompt delivery"

    Steve Monteath
    I would like to take this opportunity to thank the driver who delivered my water tank today. You are a lucky company to have such an employee. I have spent over 40 years in education & policing & it is an honour to come across young men who stand proud & tall & are a credit to themselves, their families & their employer. The water tank is on site & the pump arrived whilst the driver placed it into position. Thank you for your service & prompt delivery. I will be passing on your contact details to friends & family advising them of your service & the 'quality' of the product. Once again thank you, Steve Monteath
  • "The Driver Nathan was very competent"

    Mark R from Robertson, NSW
    To The Manager, I recently had two water tanks delivered here at Robertson by your Company, The Driver Nathan was very competent and also keen to get on with his other deliveries so we didn’t get to thank him as well as we hoped. Please pass on our many thanks to him. Thanks once Again, Mark R, Robertson, NSW
  • "well-oiled machine"

    Guys I am in the process of buying a 22,700 water tank. I would like to bring to your attention one of your employees Mr Adam Briggs. I have asked advice about many different issues & this guy has replied promptly, given great advice & has been a pleasure to deal with. I work for National Parks & look after Sydney Harbour, I have staff & know the importance of having good staff. This guy is an asset to your company. The overall make up of your company I can see already is a professional well-oiled machine. Well Done. Regards, Darren
  • Everything was done and dusted within ½ hr of the off load and the driver was on his way. Perfect.

    Hi Russell,
    Thank you for my tank received yesterday as advised. The comprehensive instructions and information available on your web page enabled me to prepare the site and ropes for the tank prior to delivery. Everything was done and dusted within ½ hr of the off load and the driver was on his way.  Perfect. By the way, your driver Greg. He denied us the pleasure of his company to share a tea break with us in his haste to get to Brisbane. We hope he made it before sunset.
    A very pleasant and stress free experience.
    Thank you.
    Regards, Paul








Round Water Tanks

Amazing Value Tanks. Up to 34,000L

Slimline Water Tanks

Great for tight spaces. Up to 5,000L

Underground Tanks

Totally out of sight. Up to 5,000L


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