Rainwater Tanks Adelaide

BLADDER TANK INSTALLATION GUIDE

1. SELECTING A TANK
Our quoted lengths and widths are the dimensions when the tanks are empty. The tanks will get
narrower and shorter as they fill. The quoted height is what the tanks will reach under gravity fed
stormwater. The height of the tanks can also be limited – see below. The required clearance above
the tank is 30mm (3cm). The quoted volume is the volume when the tank reaches its quoted height.

2. PLACEMENT AND GROUND PREPARATION
Wet Earth Bladder Tanks are specifically designed for placement under houses or verandas, but can
be used in other locations as long as the following conditions are satisfied.
For under house use the most important aim is to prevent any water from getting under the house.
These guidelines are designed to prevent or minimise the chances of water loss under the house.

2.1. Level Ground
The aim is to position the bladder tank so that it will not roll or slip. We do not recommend locating
a bladder on a surface with an angle greater than 5 degrees (12:1).
Where the bladder tank is to be placed on a surface with a slope, digging a 20cm deep channel
about half the width of the bladder tank along its length will provide additional stability. Care must
be taken when digging near walls and supports so that these are not destabilised.

2.2. Ground Type
The ground surface should not have sharp edges, or be of a material that causes slipping or
scratching.
Sand is an ideal surface, and in many cases soil is also good. Concrete is generally ok, but some
concrete surfaces might scratch the surface of the tank over a number of years.
Tanks are supplied with a Geotextile Tank Protector which provides additional protection from
puncture, slipping and scratching.

2.3. Don’t Lean
We do not recommend that bladder tanks lean against walls or structural supports as they can weigh
a significant amount when full and could contribute to movement over time.

2.4. Minimise Sunlight
To maximise the lifespan of your tank we encourage you to minimise direct sunlight exposure to
your tank. While the tanks are UV stabilised, the heat and drying effect of direct sunlight can
impact the material over time.
In most cases tanks are located under a house or veranda/deck which reduces exposure so sunlight
protection is not necessary. If a part of your tank is exposed to direct sunlight we recommend
covering it eg with shade cloth.

3. CONNECTING YOUR TANK
The aim of connecting your tank is to maximise water collection, while allowing water to overflow
into your stormwater when your tank is full. It is also important to take into account that bladder
tanks change shape as they fill and hence the fitting locations on the tank can move. All our tank
inlet and outlet fittings are located on the tank ends which minimises this movement.
The following diagrams show possible ways of connecting your bladder tank. These diagrams use
our Bladder Tank Pipe, which has some flexibility while being almost impossible to collapse.