Site Preparation and Pipework Installation for Rainwater Tanks

Are you looking to install a rainwater tank? There exist many attractive styles and tank colours today to complement your property or a modern home. One you select one however, you will then need to prepare the site where your tank will be placed. This article goes through some basic steps so that when your rainwater tank arrives your tank site is ready for your tank.

Site Preparation for Water Tanks

Correct site preparation is essential to ensuring a long and trouble-free life for your rainwater tank. To ensure the foundation of your water tank isn’t undermined through weathering and erosion, it is important to create firm and level foundations.

The site must be a solid, level and compacted base that extends 150mm beyond the diameter of the tank. It must be able to withstand erosion by wind and rain. Suitable bases include brick, concrete, gravel or solid dolomite surface between 300mm and 400mm in depth.

Water tank stands can be used, but must be designed by a qualified consulting engineer.

Moving Your Water Tank into Position

When moving your rainwater tank into position, handle with care avoiding rough and sharp surfaces and objects. Please note, you will need a sufficient number of adult able bodies person to assist driver with unloading your tank. We recommend:

  • 1 additional person for 9,000+ litres
  • 2 additional people for 13,000+ litres
  • 3 additional people for 22,000 – 27,000 litres
  • 4 additional people for 36,400+ litres

Pipework Installation to Your Tank

With your rainwater tank in position, you will need to install pipework from your roof that leads to your tank. There are two pipework options: 1) “Dry” system (above ground pipework), or 2) “Wet” system (underground pipework).

You will also want to consider accessories to install such as a rain head, water diverter, tank self-cleaning system and a rainwater-to-mains auto switching system. It is highly recommended you seek professional advice and installation by a licensed plumber. Nonetheless, here are some general steps to be following when installing pipework to your tank.

  1. Draw a plan for how you will connect downpipe to your tank, calculating how much pipe, elbows and connectors you need.
  2. Once parts are purchased, measure, cut and click pipes together. Once you are sure you have the parts needed, lay them out into sections.
  3. Smooth edges of pipes with sandpaper after cutting.
  4. Select pieces for one section, add glue to joins and connect them.
  5. Add glue to joins and connect pipes together quickly (starting with first section as necessary).
  6. Prepare holding bracket mount location on wall, attach section of piping and affix mounting bracket.
  7. Continue to glue together and attach remaining sections.

Overflow Pipework

A 90mm overflow screen and elbow is provided with Team Poly’s slimline tanks to protect against insects and vermin getting into your tank. When installing the remaining overflow pipework, it is important that it is properly supported and no undue stress is placed upon your tank or fittings:

  • All pipework from tank needs to be properly supported and not place stress upon tank.
  • Flexible piping should first be used to connect your tank to pipework which absorbs any movement, preventing stress upon tank and fittings.
  • It is often best to run overflow pipes down the wall of tank rather than horizontally out to avoid stress upon tank and fittings.

You have several options for managing the water overflow from your tank:

  • Overflow piped to ground – piped away from base of tank so that foundation isn’t undermined. You might place gravel or rocks where water flows to prevent erosion. You should first check with your local council before utilising this method.
  • Overflow piped to stormwater – you can find your stormwater pipes by digging carefully at the bottom of your original downpipe.
  • Overflow piped to another tank – underground tanks for stormwater detention is a popular option to complement your rainwater tank.
  • Overflow piped a swimming pool – great for keeping your pool water topped up although in down pours your pool can quickly fill.