Our Techline 1mm Polypropylene Impermeable Membrane is perfect for use as a barrier layer in attenuation tank wrapping.The membrane can also be used in a variety of additional applications including solid and liquid waste containment, amenity lakes and ponds, watercourse lining and balancing ponds.Where membrane meets and overlaps it should be taped using lap tape.Material: PolypropyleneThickness: 1mmWidth: 2mLength: 20m or 40mImpermeable Geotextile MembranesUnlike the permeable options, impermeable geotextile membranes do not allow any water to pass through them. They are used to retain water within an area or a structure, or to prevent water ingress into a specific area or structure.Impermeable membranes are available in rolls or in pre-formed box shapes commonly called shoeboxes.Please allow 2 - 3 days for delivery of this product.