Building Regulations
Building Regulations requires that rainwater from the roof of a building or from a paved area may either be gathered for re-use or be discharged into one of the following, listed in order:
(a) an adequate soakaway or, where that is not reasonably practicable,
(b) a watercourse (such as a ditch, stream or river); or, where that is not reasonably practicable,
(c) a sewer.
Polystorm and Polystorm Lite systems are lightweight modular water storage cells with a high void ratio that can be used to create soakways in residential, commercial, industrial and retail applications.
Polystorm crates - technical details
Each individual water crate can hold 190 litres of water (0.19 cubic meters). 1 crate should be used for every 10sq metres of roof to be drained. The cells are assembled together to form a structure of any shape or size to hold water from roofs, gutters and land drains.
The outward facing surfaces of the crates should be wrapped in
geotextile membrane to stop soil from entering and clogging up the system.
In order to form a 1 cubic metre soakaway (1m square x 1m deep) you would need 5 crates. This would be sufficient to drain an average roof area of 50sq metres.
The crates are interlocking and have knockout sections along the side to accommodate the incoming pipes.