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Cactile, tiles for rainwater storage

Designed to collect, store and use water efficiently, the Cactile system is a promising technological innovation in urban water management. Its aim is to reduce the impact of urban buildings on soil sealing and to slow down the water cycle by recovering rainwater from roofs.
Cactile, tiles for rainwater storage
Cactile, tiles for rainwater storage

At a time when water management in cities represents a major challenge for the planet, the start-up Cactile — a fusion of “cactus” and “tile” — has developed a system of modular tiles equipped with extra-flat tanks to collect rainwater and store it for later use. The recovery efficiency of a tile varies from 70% to 100% depending on the slope of the roof structure and the intensity of the rain.

A smart multi-layer water management system

Suitable for pitched roofs and building façades, it can be installed on new or existing buildings. It consists of three layers, selected using a sophisticated eco-design approach. The first, made from recycled polypropylene, provides an initial level of waterproofing for the roof, while the second layer, made from recycled HDPE, includes a reservoir capable of storing 40 litres of water per square metre. Once full, the tank can be emptied using a connected box and used to supply the toilet or water the garden, for example. If heavy rainfall is forecast, it can be emptied in advance to act as a buffer reservoir and protect the communal networks. The top layer provides the main waterproofing.  It is made of metal, a lighter material than terracotta. When fully loaded, the whole system weighs no more than a traditional roof.

Solutions to help cities adapt to the effects of climate change

The Cactile system helps save drinking water while limiting the impact of flooding through run-off.

This limits both the cost of treatment and the risk of run-off.

In addition to its function as a water collector, other functions are being studied, such as the possibility of producing electricity to contribute to the energy autonomy of buildings, or the possibility of greening roofs to promote urban biodiversity and reduce urban heat islands.

Cactile is currently carrying out physical tests on its new tile system. The first projects are scheduled for 2025 on public buildings and buildings belonging to companies committed to the ecological transition. These pilot projects will be used to prepare the certification application with a view to rolling out the solution on a larger scale.

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