True gas barrier geomembranes are manufactured with 7-layer co-extrusion technology in various widths from 2 to 10m. Their outer layers can be composed of various materials, depending on required properties - such as HDPE for strength and chemical resistance, LLDPE for elasticity or special polyolefin alloys and compounds that combine strength with softness. The middle layer is made of EVOH (Ethylene Vinyl Alcohol), a polymer with extremely low permeability to gases. As a result, the 7-layer barrier geomebranes combine the strength and weldability of polyolefins while being virtually impermeable to gases.
Some of the applications where these barrier liners can be used are:
- Radon barrier
Radon is an invisible, odorless, tasteless, radioactive gas. Inhaling radon increases the risk of lung cancer. The concrete floor and walls in the basement slow down the movement of radon from underground into the building, however, cracks in the floor, wall slab joints and the drainage system allow radon to enter. Lining under concrete slabs with a true gas barrier liner is essential for preventing radon's harmful effect in regions with high levels of emission.
- Methane gas barrier
Methane gas can migrate significant distances under the ground surface and be forced into buildings causing accidents by ignitions or explosion. True gas barrier liners are used to prevent such incidents in regions with high concentration of methane gas.
- Containment and remediation of contaminated soil
Lining with true gas barrier liners during in situ and ex situ remediation of contaminated soil offers faster remediation and is an excellent measure to prevent gas emissions. A 2 mm geomembrame could provide the necessary gas barrier effect, however, it is difficult to manipulate and install. A thinner, more flexible gas barrier liner that can be produced in large widths and is capable of being pre-fabricated in large surfaces, is a much better solution in terms of cost, speed and ease of application.
Brownfield is, according to EPA, a real property - the expansion, redevelopment, or reuse of which may be complicated by the presence or potential presence of a hazardous substance, pollutant, or contaminant. Often brownfields are abandoned or under-used industrial/commercial facilities that have been producing high levels of subsurface contaminants during their operation. A true gas barrier liner under the concrete slab is a very useful method for eliminating the influence of VOC emissions into the building.
- Landfill capping
Capping of a landfills is commonly designed with 1-2 mm HDPE or LLDPE geomembranes. Our true gas barrier liner with EVOH has a much lower permeation to VOC gases, thus preventing the spread of odors and permitting to collect a higher quantity of methane from the landfill.