Hewitech’s in-house installation team with over 10 years experience offer customers a complete supply and fix solution warrantied for 30 years.

For attenuation systems Hewitech LLPE Membrane is wedge welded and the joint air tested at 1 bar in accordance with “CIRIA 768 Site handbook for the construction of SUDS“. C768 states – “All storage tanks should be fully sealed in accordance with waterproofing standards, i.e. welded joints rather than adhesive tape, and the integrity of the seal checked through non-destructive testing, to ensure it is leak-proof.”

Attenuation tanks and soakaways are installed in an excavation prepared and backfilled by the contractor.

For protection the LLPE Membrane is surrounded with a 300g needle punched non- woven geotextile

Hewitech have experience installing complex tanks with the Variobox sited and membranes welded around pipe caps and crane bases

Welded Construction
Pressure Testing
Pipe connections are made by forming the membrane around a coupler to enable the contractor to connect the drainage runs to the tank.

Soakaway systems are installed by surrounding the Variobox with a 120g needle punched non- woven geotextile

Hewitech’s installation team also install membranes for other forms of SUDS such as storage below permeable car park surfaces and open lagoons.

Hewitech can prepare working drawings when supplied with a customer’s CAD file

Needle Punched Non Woven Geotextile
“We found Hewitech very easy to work with, all materials arrived on time and the whole process went very smoothly, with no problems. We are very happy with the end result.”


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