Rainsmart Soakaway Set For Heavier Soils Assembled 1 Cubic Metre
This soakaway set is comprised of four Rainsmart Ellipse Soakaway Crates (24.2-tonne vertical load capacity) with a covering of 2.4m x 2m x 30mm Nero drainage cells sitting above the main body of the soakaway. The kit includes a sufficient non-woven geotextile membrane to wrap all outward faces of the soakaway including the base and the drainage cells above. Also included are cable ties for holding the crates together until the side fill has been introduced.
Size, load and capacity
The dimensions of the complete soakaway are;
- Main Soakaway Body - 1430mm (L) x 800mm (W) x 860mm (D)
- Drainage Cells Above 2400mm (L) x 2000mm (W) x 30mm (D)
All Rainsmart soakaway crates have a void ratio of 95% - this is the amount of free space within the crate structure that can be used for rainwater storage. The capacity of this soakaway is 1071 Litres. Under soil normal conditions this would be sufficient to hold water from a roof area of approximately 56 square metres.
The vertical crush load capacity of 24.2 tonnes per square metre ensures that the Rainsmart Ellipse crates are safe to be used beneath gardens and pedestrian areas. The lateral crush load of 18 tonnes per square metre is the best of any type of soakaway crate currently available in the UK.
The science bit
Heavier soils hold rainwater within the soil particles for longer, slowing down the infiltration rate. This means that in heavy rainfall conditions the soakaway void will fill up quicker than normal. By introducing a layer of 30mm cells laid out in a table style above the soakaway crates, the soil contact area for infiltration is greatly increased - the 30mm cells have a surface contact area that is over four times as large as the soakaway body.
Note though that soils that are comprised completely of clay are not generally suitable for soakaways, due to the infiltration rate being so slow. If in doubt we recommend that you carry out a soil percolation test.
Joining crates together
Clips are not required to hold the crates together. No clips on any crate system are structural it is always the side fill on any soakaway installation which adds the stability needed to hold the structure in place. Cable Ties are included with our 1m³ Soakaway Sets and these are used purely to hold the crates in place until the sand or gravel side fill has been added.
All outward-facing crate surfaces of any soakaway or drainage cell should be wrapped in a non-woven geotextile membrane, which allows the free passage of water but prevents any soil or sand particles from entering the soakaway, maintaining its long term efficiency.
Connecting Pipes to Soakaways
The 110mm (or 160mm) drainage pipe is fed into the main soakaway body via one of the four circular 160mm open entry points. 110mm pipes simply rest on the bottom of this opening and we recommend that the pipe is inserted approximately 150mm inside the crate. 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 or clamp the membrane tightly around the outside of the pipe to stop the ingress of any soil particles. Pipe entry points do not affect the structural integrity of the soakaway in any way.
Consider a Silt Trap
For best practice, we always recommend that a pre-filter such as our Sentinel Silt Trap is used in conjunction with any modular soakaway system. Emptying the filter on a regular basis (this is only a five-minute job) will maintain the efficiency of the soakaway and greatly increase its lifespan.
For a closer look at Soakaway Crates in general, including installation tips, please take a look at our detailed introductory video.
