Soakaways & Landscaping

Modern soakaways are modular structures built using plastic water crates or cells. They have an extremely high void ratio, allowing them to maintain their structural integrity whilst holding large amounts of water. Soakaways are generally used to dispose of rainwater on most new build projects, both domestic and commercial. Soakaways should always be wrapped in geotextile membrane to prevent soil particles from clogging up the void area.


Soakaways are a step forward in drainage technology, replacing traditional inefficient soakaways filled with hardcore and building waste and providing a safe and intelligent solution to rainwater management. The void ratio of a Rainsmart Soakaway is 95% - this means that 95% of the total soakaway space is used to hold rainwater.

Each individual Rainsmart Double module (there are 4 per cubic metre) holds 235 litres of rainwater. Polystorm water crates (5 per cubic metre) can hold 190 litres of water. The Aquavoid Crates have a holding capacity of 316 litres (3 per cubic metre). A 1 cubic metre soakaway is generally sufficient to drain an average roof area of 50sq metres in normal soil situations.

Soakaway crates have very high load bearing capacities and can installed under driveways and car parks. Our Rainsmart Ellipse crates have a vertical crush load capacity of 24 tonnes and an industry leading lateral load capacity (side loading) of 18 tonnes. Our heavy crate systems have a vertical load capacity of 65 tonnes.


Our Rainsmart soakaway crates are available in a flat pack option for assembly on site. A standard 1 cubic metre soakaway should take around 10-12 minutes to assemble, the only tool required is a rubber mallet which we supply as part of the kit.

Flat Pack soakaways are slightly more cost effective as they are easier to and handle and transport. They are ideal for both large and small sites where space is at a premium.

Ellipse Double Soakaway Crate


The modular nature of soakaway crates helps builders and architects to create soakaways in a variety of shapes and designs, from shallow installations to soakaways that need to be installed in tight spots. You can even arrange the modules in a corner layout if you are very tight for space.

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 Polystorm crates, or 3 Aquavoid Crates.


Our Rainsmart Soakaway modules are eco-friendly, being made from recycled polypropylene. Well designed soakaways enhance water quality and play a crucial part in recharging groundwater supplies.


The crates are lightweight and can be installed by unskilled labour if required, without the need for heavy plant on site.


Our Rainsmart crates have a 160mm open pipe entry point. 110mm pipes simply rest on the bottom of this opening and we recommend that the pipe is inserted approximately 150mm into the opening. Geotextile membrane should be installed over the opening first and then a small cross should be cut in the membrane at the entry point with a sharp knife. Carefully peel back the membrane, insert the pipe and tape the membrane around the outside of the pipe for a clean joint. Pipe entry points do not affect the structural integrity of the soakaway in any way.

Polystorm and Aquavoid crates have knockout sections along the side to accommodate the incoming pipes. The process for cutting and taping the membrane around these knockouts is the same as for the Rainsmart crates. 


Please note that our pre-assembled soakaways crates incur an additional £10 delivery charge due to their bulky nature. No additional charge is made for flat packed soakaway deliveries.

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