Rainwater Harvesting System

‘The RainMax’

Collecting your rainwater WILL save you money

Why harvest rainwater from your roof?

The average family of four in Ireland uses 436 litres of water per day, through activities like showering, flushing toilets, washing clothes, cooking and watering outside. As it rains 188 days per year on average in Ireland we have every reason to collect this water and use it to significantly reduce our mains water demand.

Did you know that by harvesting the rainwater from your roof you can reduce your mains water demand by up to 55%?

Much of the water we use doesn’t need to be of drinking quality. In fact studies show that 55 per cent of domestic treated water could be substituted for rainwater while 85 per cent of water used for commerce and industry does not need to be of drinking standard.

With the introduction of water charges, we will now see water conservation drive to the top of the construction agenda.

How does the ‘RainMax work?

The ‘RainMax System’ collects rain from your roof, filters any leaves and solid particles before storing the water in a sealed tank below ground. This water is then pumped from the tank into the house on demand. Both ‘Direct System’ and ‘Indirect System’ options are available.l'l;'


What can I use rainwater for?
Rainwater can be safely used for a variety of non-potable purposes including flushing toilets, washing machines, cleaning cars and watering the garden. It is also possible with further treatment to use for showers and bath water.

What happens when there is no rain?

When there is a prolonged spell without rain, the water level in the storage tank will fall to a minimum level. At this level, a float switch will open a valve from the normal mains supply and keep the storage tank topped up, until it is filled by rain again. Normal system design should allow up to a week without rain, given normal usage.

Do I need a large roof area to provide an adequate supply of water?
A surprisingly small roof area will collect a lot of rainwater: a typical terraced house with a 6 by 8 metres roof area could give 30,000 litres a year depending on the area of the country you live in.

How is water pumped to my house?

Water can be distributed to the house using an indirect gravity system or a direct pressurised system. The gravity system includes a header tank positioned into the attic, to which the rainwater is pumped from RainMax system. From here it flows via gravity to each application within the house. The pressurised system eliminates the need for the header tank, and a pressure vessel is installed to maintain a consistent pressure in the subsequent pipe network.

What is the RainMax tank made of ?FinalHighres01

The ‘RainMax’ rainwater harvesting system is available in reinforced precast concrete as well as fibreglass.


  • Reduce your water bills by up to 55%
  • Reduces limescale build-up in pipe work and appliances
  • Soft Water – Reduces amount of detergents required
  • Environmentally friendly – takes pressure off mains supply
  • Pressurised and Gravity Systems available

Components Included:

  • Includes 4000 litre or 8000 litre tank
  • EN standard self cleaning SS filter (up to200sqm roof area)
  • Filter with calmed inlet
  • Stainless steel automatic pump with automatic pressure sensor
  • Separate cleanable non return valve to prevent blocking and pump failure
  • Tank overflow siphon with rodent barrier
  • Built in leak detection in pump software
  • Floating intake with filter and hosetail
  • Mains water top up control unit with alarm,
  • Water Level probe in tank
  • EN standard tundish
  • Pressure Vessel (for direct system) and header tank (for indirect option)
  • Delivery to site and fitting using a truck mounted crane

Rainwater harvesting saves money, reduces surface water from your property and may offer a storm water management solution.