Shallow sub-base attenuation and source control is Forma’s sweet spot, it’s where we specialise, and where our industry knowledge has been honed – enabling us to inform the industry how to best manage surface water run-off across large areas.
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Formavoid is the product of all our efforts to bring to the construction industry something different, something that enables shallow installation. The Formavoid system optimises shallow sub-base attenuation and source control, meaning no deep excavations and large cumbersome tanks – just a system that uses aggregates and arches to create a structural void raft, smaller diameter pipes, smaller chambers, and an altogether smarter, more streamlined, cost-effective drainage solution, whilst helping towards reducing risk on-site.
We aren’t just committed to water management, we’re committed to challenging the standard.
Sectors
The maverick saviour
for Civils and Sports sectors
For years, the civils and sports sectors have relied upon conventional deep-tank excavation flood water management methods to alleviate standing water. But today, there’s a new player on the field. Our innovation in shallow sub-base attenuation brings Formavoid® to the game.
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Our mission is to provide engineered systems for the next generation of source control subbase attenuation. With well thought out accessible inlet & outlet products along with specially selected geofabrics to compliment the Formavoid attenuation units, we have developed the ultimate shallow subbase attenuation system.
Introducing
The Forma Way
We're pulling stormwater attenuation out of a hole.
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Our methodology is to manage stormwater as close to the source as possible, spreading the attenuation or infiltration over a large area but keeping it shallow and just below the surface within the subbase layer. We do this by using Formavoid to increase the storage capacity of open graded granular subbase attenuation to keep subbase depths shallow and reduce the reliance on tanks. The clever part is how we have made this possible beneath all kinds of surface, both permeable and impermeable.
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To be most effective we need a good storage area, for example a car park, service yard, paved area or sports field. The Forma way is extremely effective when the Formavoid can be implemented beneath the whole catchment area - removing the need for any tanks or large chambers and pipework. If there are greater contributing areas such as roofs, we simply attenuate the roof runoff in a modest tank, and attenuate the external areas within a shallow subbase.​
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Shallow attenuation
Above formation attenuation, avoiding hard dig, ground water, buried services, ground gas, ground contamination, excavation collapse, large tanks/chambers and large clunky pipe networks.
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Boundless versatility
The Forma system provides shallow attenuation for car parks, service yards, paved areas, synthetic sports fields, court sports, natural/hybrid sports fields, podium decks and many more.
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Low-risk compliance
The Forma system is not just compliant with modern sustainable drainage regulations, it is leading the way. A straightforward shallow solution, minimising the risks associated with excavation from a design and installation perspective.
Products
Formavoid Changes
Everything
A simple shallow, trafficable solution, creating void space just beneath the surface for managing rainwater at source.
The Formavoid module is shaped to encourage aggregates into structural columns & arches. Load is spread through the fill material to the columns, creating an extremely strong & robust product. The space beneath the arches remains open, creating a shallow void space for stormwater management just beneath trafficable or sports surfaces.
