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Rainwater Diffuser Units for Effective Subbase Attenuation Tanks & Sustainable Drainage Systems (SuDS)
Made in the UK
High quality sustainable water management products designed and manufactured in the UK
Technical Support
We are committed to provide full technical support in line with current legislation & guidance
Permavoid Rainwater Diffuser Units
Permavoid Rainwater Diffuser Units are designed for the efficient diffusion of collected rainwater run-off into and out of the voided sub-base aggregate layers beneath permeable pavements safely dissipating the energy of incoming surface water flows. By distributing inflows across a wider area, diffuser units help minimise localised scour, reduce turbulence and improve the hydraulic performance of subbase attenuation within Sustainable Urban Drainage Systems (SuDS).
During heavy rainfall events, concentrated inflows entering an subbase can create high-velocity discharge points capable of disturbing surrounding stone, washing away fines and reducing the long-term effectiveness of the storage system. Permavoid diffuser units are specifically engineered to spread these flows evenly throughout the subbase attenuation structure at surface water entry points, helping to protect both the subbase attenuation and surrounding components.
surface water management
Key Benefits
Efficient Diffusion
Recognised method for efficient diffusion of rainwater into and out of the voided sub-base aggregate
Standard unit sizes for simple design integration
The Original
Strong and lightweight
fully compliant with BS7533-13:2009
Special project-specific sizes available upon request
Easy to Install
One-piece installation
Supplied with integral socket connection
Suit stardard uPVC pipe sizes
Product Information
PVOD05101 Diffuser Unit 710x710x150
The Permavoid Diffuser Unit 710x710x150; 110mm ø Socket is used for the efficient diffusion of collected surface water runoff in or out of permeable aggregates. This technique can be utilised in junction with both pervious and impervious surfaces, in
particular where there are high groundwater levels, contamination or shallow rock layers. Each diffuser module is complete with a preformed 110mm Ø push fit socket for easy connection to standard PVC-u underground pipework. All diffusers are encapsulated by a 2mm mesh which avoids debris clogging and provides an excellent open surface area for surface water runoff to easily flow into the surrounding aggregate.
Each diffuser unit is suitable for 100m² catchments or 3 l/s discharge
PVOD05202 Diffuser Unit 2130x355x300
The Permavoid Diffuser Unit 2130x355x300; 160mm ø Socket is used for the efficient diffusion of collected surface water runoff in or out of permeable aggregates. This technique can be utilised in junction with both pervious and impervious surfaces in particular where there are high groundwater levels, contamination or shallow rock layers. Each diffuser module is complete with a preformed 160mm Ø push fit socket for easy connection to standard PVC-u underground pipework. All diffusers are encapsulated by a 2mm mesh which avoids debris clogging and provides an excellent open surface area for surface water runoff to easily flow into the surrounding aggregate.
Each diffuser unit is suitable for 250m² catchments or 6.3 l/s discharge
