Impermeable membrane in a shoebox design for use with our heavy standard (690mm deep) 20 cubic metre attenuation tanks. This liner is used to wrap around the geocellular attenuation units and is usually supplied in two fabricated pieces. The first is the base while the second is for the top with a small overlap down the sides. The two pieces effectively make a shoebox.Impermeable membrane will hold water within the structure which can then be released into the mains network or recycled for re-use. The pieces will come folded in a concertina fashion on pallets with clear instructions as to where to place, unroll and pull out.The shoebox impermeable liner comes with a non-woven protector geotextile which should wrap around the whole system before backfilling.Top hat, double-sided tape and jubilee clips are also included for complete installation.For installation advice and guidance please take a look at our attenuation system installation guide. The Landflex AS shoebox attenuation liner is designed to fit on our pre-sized commercial soakaways in 5, 10, 20 and 50 cubic metres. Please note that we can cater for whatever size system you need so please get in touch to receive a personalised quote for your exact system measurements. For larger applications several panels can be pre-fabricated and welded together off site, custom ready for final jointing on site, greatly reducing installation times.Please Note - as this product is made to order it will take 7-10 days for delivery.