Stormwater Attenuation & Soakaway Modules
Polypropylene geocellular modules for below-ground attenuation tanks and soakaways. Standard 1000 × 500 × 400 mm format, about 95% void, light- to heavy-duty load classes.
- Minimum order
- Typically from one pallet for sampling; project and merchant orders by the 20′ or 40′ HQ container.
- Lead time
- Confirmed in each quotation after capacity check with the manufacturer.
Geocellular modules build a below-ground void that stores run-off (attenuation, wrapped in an impermeable geomembrane) or lets it infiltrate (soakaway, wrapped in geotextile). Modules are stacked and laid side by side to reach the storage volume set by the drainage design.
We supply the module families that UK and Australian contractors specify most often and match them to the load class your engineer needs: landscaped areas and gardens, car parks, or trafficked areas with heavier cover. Because the same factories also produce inspection modules and the wraps can be sourced alongside, one order can cover the complete tank kit.
What to send with your RFQ: required storage volume or module count, module size, load class (or the maximum cover depth and traffic category), wrap type, and whether you need inspection access.
Key specifications
| Common module formats | 1000 × 500 × 400 mm; 1000 × 500 × 500 mm; 1000 × 1000 × 400 mmOther heights on requestSource: rainwaterharvestingsystem.net |
|---|---|
| Gross volume per module | ≈ 0.20 m³ (1000 × 500 × 400); ≈ 0.40 m³ (1000 × 1000 × 400)Source: duratex.co.uk |
| Void ratio | Typically 95%Source: aquarainwater.com |
| Vertical load class | Light-duty to heavy-duty; published classes include 32 / 45 / 60 t per m²Load class must match cover depth and traffic in the designSource: yuderaineco.com |
| Lateral strength (example) | > 110 kN/m² on a 1000 × 1000 × 400 moduleSource: duratex.co.uk |
| Material | Polypropylene (virgin or recycled PP grades)Source: aquarainwater.com |
| Unit weight (example) | ≈ 16 kg for 1000 × 500 × 400Source: rainwaterharvestingsystem.net |
| Wrap | Geotextile (infiltration) or geomembrane (attenuation)Source: aquarainwater.com |
Typical, configurable ranges compiled from published manufacturer data. Final values are confirmed per order in the quotation and supporting test documents.
Materials
Injection-moulded polypropylene. Recycled-PP versions are available for cost-sensitive, lightly loaded applications; confirm the load class against the manufacturer’s test report.
Dimensions & formats
Modules interlock with clips or pins. Layouts from a single layer to multi-layer tanks; the number of layers is limited by the load class and cover depth.
Options & customisation
- Private-label moulding marks and cartons for merchants
- Kits packed per project (modules + wraps + inspection units)
- Colour depends on material grade (typically black)
Applications
- Private and commercial soakaways
- Attenuation tanks under car parks
- SuDS for residential developments
- Rainwater harvesting storage (with suitable liner)
- Sports pitch and landscape drainage
- Retrofit storage under existing hardstanding
Ordering information
Minimum order
Typically from one pallet for sampling; project and merchant orders by the 20′ or 40′ HQ container.
Lead time
Confirmed in each quotation after capacity check with the manufacturer.
Packaging
Palletised and stretch-wrapped; knock-down designs reduce shipping volume.
Loading & shipping
Container loading plan provided with the quotation. Stackable and knock-down formats differ considerably in modules per container.
UK and Irish buyers often expect third-party load testing (for example BBA). We quote only modules whose test documents we can supply and state clearly when a national approval is not held.
Technical documentation
- Product data sheet (manufacturer)Available on request with your RFQ
- Vertical and lateral load test reportWhere held by the manufacturing partner — confirmed per module
- Installation guidanceAvailable on request with your RFQ
- Pre-shipment inspection reportAvailable on request with your RFQ
Frequently asked questions
How many modules do I need?
Divide the required storage volume by the module volume × void ratio. Our crate calculator does this and prefills your RFQ.
Soakaway or attenuation — what is the difference?
A soakaway is wrapped in permeable geotextile so water infiltrates into the ground. An attenuation tank is wrapped in an impermeable geomembrane and releases water at a controlled rate through a flow control.
Can the modules take vehicle loads?
Only heavy-duty classes installed at the designed cover depth. The drainage designer sets the load class; tell us the traffic category and cover depth so we quote the right module.
Research references
Related products
Request a Quotation: Stormwater Attenuation & Soakaway Modules
Tell us what you need. A specialist reviews every request and replies with a quotation or clarifying questions — usually within one business day.