5 lines · Crates
Attenuation crates
Geocellular attenuation crates from Stormmaster, Hydrocell, StormGuard and GRAF, priced on enquiry and delivered to site, or built into a welded, tested tank by our own crew.
Attenuation crates
SUP-15Enquiry onlyCrates
Stormmaster 40t Attenuation Crate
1m × 1m × 0.4m geocellular crate, 95.8% void
- Unit size
- 1m × 1m × 0.4m
- Void ratio
- 95.8%
- Load rating
- 40t
POA
Engineered to your Qmax
SUP-13Enquiry onlyCrates
Hydrocell 62t Attenuation Crate
1m × 0.5m × 0.4m crate, 62t rated, 95% void
- Unit size
- 1m × 0.5m × 0.4m
- Void ratio
- 95%
- Load rating
- 62t
POA
Engineered to your Qmax
SUP-14Enquiry onlyCrates
StormGuard+ 40t Attenuation Crate
1m × 0.5m × 0.5m geocellular crate, 96% void
- Unit size
- 1m × 0.5m × 0.5m
- Void ratio
- 96%
- Load rating
- 40t
POA
Engineered to your Qmax
SUP-12Enquiry onlyCrates
GRAF Ecoblocc Maxx Attenuation Crate
0.8m × 0.8m × 0.35m GRAF crate, 96% void
- Unit size
- 0.8m × 0.8m × 0.35m
- Void ratio
- 96%
- Priced
- On enquiry
POA
Engineered to your Qmax
SUP-11Enquiry onlyCrates
GRAF Ecoblocc Flexx Inspect
0.8m × 0.8m × 0.35m GRAF crate, inspectable
- Unit size
- 0.8m × 0.8m × 0.35m
- Use
- Attenuation · soakaway
- Priced
- On enquiry
POA
Engineered to your Qmax
Choosing an attenuation crate
An attenuation crate is a plastic box, mostly empty space, built into a block underground to hold stormwater back during heavy rain. Wrapped in welded membrane it becomes an attenuation tank that lets the water out slowly through a flow control. Wrapped in geotextile on ground that drains, it becomes a soakaway.
The drainage design decides the crate, not the brand. Four things matter: the loading over the tank (landscaping, a car park or a road), the depth of cover, the void ratio and how much storage fits in the footprint, and whether the tank has to be inspectable once it's buried.
Working out the storage
Storage per crate is the unit's volume times its void ratio. A 1m × 1m × 0.4m crate at 95.8% void holds about 0.38m³, so a 100m³ tank needs about 261 of them. Each product page gives the storage per unit and how many units make a cubic metre.
Send us the engineer's drawing and we'll do the count, the layout and the membrane and fleece quantities with the crate price.
Supplied, or installed by us
We'll deliver crates to site for your own team, or build the whole tank: fleece on the formation, membrane welded with every seam tested, crates built to the drawing, pipes sealed with top hats, and the QA records handed over at the end. We also install crates you've bought elsewhere.
Frequently asked questions
The crates are the same; the wrap is what changes. An attenuation tank is sealed in impermeable membrane and releases water slowly into the drainage network. A soakaway is wrapped in permeable geotextile so the water soaks into the ground, which only works where the soil drains.
Whichever your drainage engineer specifies for the loading, cover depth and storage. If the drawing leaves the choice open, tell us the site and what passes over the tank and we'll suggest a crate that meets it.
Yes. Every crate here can be supplied on its own and delivered to site. Supply and install is there if you want it.
The price depends on the quantity and the delivery to your site. Send the tank size or the drawing and we'll come back with a price, usually within a working day.
Tell us about your project
Quote back within one working day