GP®H Hydrocarbon and Gas Barrier is a monolayer, high density polyethylene membrane. Specifically designed and manufactured to perform as a hydrocarbon and VOC, air and moisture protection system. GP® H is chemically resistant to a range of hydrocarbons, acids and aggressive ground salts, providing a solution for a range of demanding applications.

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Product Benefits

  • High quality reinforced polyethylene membrane.
  • Low permeability to hydrocarbon and VOC vapours, carbon dioxide, methane and radon.
  • Complies with latest codes of practice as published by the BRE and CIRIA, and BS 8485.
  • Provides resistance to root penetration from invasive species.
Product Description

GP® H – high performance SUDS, permeable paving, hydrocarbon and gas barrier is a mono layer, high density polyethylene membrane specifically designed and manufactured to perform as a robust hydrocarbon protection system, which is suitable for use in various demanding geomembrane applications where hydrocarbons are present.

GP® H is a fully weldable, category 2 attenuation grade liner fully conformant to C753 and BS7533-13 (Code for
Sustainable Homes 2006) and is CE marked for use in the following application areas: EN13361, EN 13362, EN13492, EN13493, EN13382 (listed requirements for SUDS system impermeable liners).

GP® H complies with the latest codes of practice as published by BRE and CIRIA. Suitable for use as gas and vapour protection for NHBC GREEN and AMBER 1 site characterisations. GP® H is also suitable as a hydrocarbon barrier for attenuation tanks, permeable paving and structural waterproofing.


GP® H provides resistance to root penetration from invasive species, including (but not limited too): Japanese Knotweed, Bamboo, Mustard Seed, Meadow Grass, Ivy, Hybrid Poplars, Willow, Elm, Maple, Mare’s tail, ground creeping plants, edible plants and aquatic plants.

MaterialPolyethylene high-density (PE-HD)
ShapeRectangular Flat sheet - supplied in roll form.
SizeVarious widths, lengths and thicknesses available.
Warranty Description60 year Minimum.
Uniclass 2015Pr_25_57_65_60 Plastics sheets
CAWSJ40/35 Loose laid plastics or rubber gas retardant damp proofing
J40/140 Loose laid plastics or rubber sheet gas retardant damp proofing
J40/145 Loose laid weldable polyethylene gas retardant damp proofing
Product rangeJunifol Geomembrane
MaterialHigh-density polyethylene (PE-HD).
PurposeProtection layer.
Standard To BS 7533-13.
Performance characteristics
Tensile strength (minimum) 850 N/50 mm.
Tear resistance To ISO 34-1, 140 N.
Elongation to break 140 N.
Resistant to underground gases <55 ml/ m2/ day/ atm
Water vapour resistance (minimum) 300
Third-party certification CE Marked to EN 13967, EN 13361, EN 13362, EN 13492, EN 13493, EN 13382.
Physical properties
Thickness (minimum) 1 mm.
Width (minimum) 2.5 m.
Roll length (minimum) 25 m.
Environmental information
Country of material origin Czechia
Recycled content 0%
CharacteristicsFeature Characteristics Test Method GP® H
ThicknessEN 1849-21.0 mm1.5 mm
WidthEN 1849-25.1 or 2.5 m5.1 or 2.5 m
LengthEN 1849-2100 m or 35 m100 m or 25 m
DensityEN ISO 11830.939 g/cm3
Resistance to RootsCEN/TS 14416Impenetrable
CharacteristicsTest MethodGP® H
Permeability to liquidsEN 141501.0 x 10-6 m3 /(m2.d)
Water Vapour TransmissionEN 1931300 m
Water Tightness (6o kPa)EN 1928Pass
CharacteristicsTest MethodGP® H 1.0 mmGP® H 1.5 mm
Resistance to Static LoadEN 12730-B> 20 kg> 20 kg
Tensile Strength (MD)EN 12311-1850 N/50mm1000 N/50mm
Tensile Strength (CMD)EN 12311-1850 N/50mm1000 N/50mm
Tensile Elongation (MD)EN 12310-1950 %950 %
Tensile Elongation (CMD)EN 12310-1950 %950 %
Puncture ResistanceEN 122363200 N4300 N
Resistance to ImpactEN 12691(A)> 700 mm
Tear StrengthISO 34-1140 N
Shear Resistance of Welded JointEN 12317-2850 N/50mm
CharacteristicsTest MethodGP® H 1.0 mmGP® H 1.5 mm
Transmission Rate of Volatile Liquids - DieselISO 6179:2010 (B)0.047 g/m2/h0.026 g/m2/h
Transmission Rate of Volatile Liquids - XyleneISO 6179:2010 (B)1.886 g/m2/h0.549 g/m2/h
Transmission Rate of Volatile Liquids - TolueneISO 6179:2010 (B)4.432 g/m2/h0.987 g/m2/h
Transmission Rate of Volatile Liquids - PetrolISO 6179:2010 (B)2.318 g/m2/h0.623 g/m2/h
CharacteristicsTest MethodGP® H
Methane PermeabilityBS EN ISO 15105-1< 55 ml/m2/day/atm
Carbon Dioxide PermeabilityBS EN ISO 15105-1< 55 ml/m2/day/atm
Radon PermeabilityK124/02/951.1 x 10-11 m2/s

GP® H is a robust weldable geomembrane suitable for attenuation tank encapsulations, porous sub-base installations, containment and cut-off trenches, structural waterproofing. GP® H is suitable for use where sites are affected but various hydrocarbons and VOC’s. GP® H is a chemically inert membrane offering designers and specifiers a range of critical properties that meet the needs of today’s demanding geomembrane applications including high water table sites. GP® H can be fully welded where required.

For use in various demanding geomembrane applications where hydrocarbons are present. Suitable for use as gas and vapour protection for NHBC Green and Amber 1 sites. Also suitable as a hydrocarbon barrier for attenuation tanks, permeable paving and structural waterproofing.


GP® H should be installed on a blinded or smooth surface, free from sharp protrusions (typically maximum permissible particle size in direct contact with the membrane should be <10 mm). Avoid areas of unsupported membrane. Where required, adequate protection should be applied over the membrane to prevent damage after installation. GP® H exhibits superior welding properties, making it ideal for on-site welding joints.


A selection of standard details for information and education purposes only. Note - it is strongly advised appropriately qualified, and insured personnel undertake gas membrane installs. A gas membrane performs a critical function in the application setting and has an anticipated design service life in excess of 60 years. Do not attempt to install gas membranes from these details alone. Sole rights for use and distribution are owned by JUTA UK LTD.

Store in a warm clean and dry environment, with rolls stacked no more than 5 units high. GP® H is classified as non-hazardous. It is chemically inert and is not affected by acids and alkalis that may be present in the subsoils. The material is not recommended for uses where it will be exposed to long periods of outdoor weathering, such as exposure to Ultraviolet light that will embrittle the product. Care should be taken to avoid accidental damage when handling the membrane on site.

CE Mark
CE Mark - EN13967:2012
CE Mark
CE mark - EN13361, EN13362, EN13492, EN13493, EN13382
BSI Kitemark
BS7533-13 and ‘Code for Sustainable Homes 2006’ Conformant
Ciria Logo
Conforms to CIRIA C697 and C753 as an Attenuation Membrane
BBA Certificate 20 5728
BBA Certified - Certificate No. 20/5728
Site Investigation
Site Investigation
Site Investigation Reports Monitoring Results. We review these reports and advise routes for compliance.
System Design
System Design
Full Ground Gas Protection System Design available.
Wide library of standard details with site specific details on request.
All our installers are certified NVQ Level 2 qualified installation contractors.
We ensure your project complies with the relevant building regulations.

Ground Gas Standards

There are many different standards and guidance documents that detail how to understand the risk of ground contamination, and design solutions to mitigate these risks. The different documents relate to different ground contamination. Below are some of the key documents to be aware of and refer to:

BS 8485:2015+A1:2019 – Codes of practice for the design of protective measures for methane and carbon dioxide ground gases for new buildings.

  • Ground gases are typically found near landfill sites but can occur from other sources
  • Encourages the use of qualified installers
  • Validation to Ciria C735 is a requirement
  • Additional influences on the system should be considered, such as the hydrostatic conditions, and the likelihood of the source contaminant being in direct contact with the protective measures proposed

BRE 211:2015 – Guidance on protective measures for new buildings. (RADON)

  • Naturally occurring ground gas. Larger concentrations in the South-West of UK
  • Minimum recommendation is a membrane of 300 micrometre (1200 gauge) polyethylene sheet or equivalent
  • It must be installed with considerable care and protected once installed
  • Taped laps are required

CIRIA C748:2014 – Guidance on the use of plastic membranes as VOC vapour barriers

CIRIA C682:2009 – VOC Handbook

  • Risk-based approach
  • No quantifiable limits on material performance
  • Testing to ISO 15105-2 and EN 14414/EN 14415
  • 9 main VOC types are tested for
  • Welded laps are required as most tapes are made from bitumen/butyl and are affected by VOCs

CIRIA C735:2014 – Good practice on testing and verification of protection systems to buildings from hazardous gases

  • Good practice on testing and verification of protection systems to buildings from hazardous gases
  • Check design and detailing is in accordance with site requirements
  • Checks the competency of the installer (NVQ LEVEL 2 minimum)
  • Test integrity of the membrane/barrier system
  • Visual inspection
  • Written report on inspection/testing and sign-off

BS8102:2009 – Code of practice for protection of below ground structures against water from the ground


JUTA Solutions & Applications

Our gas protection membranes suit a variety of applications and situations, with our TITAN® range offering not only gas protection but also having superior waterproofing and invasive weed control qualities.

BRE 211 NHBC (Amber 1) BS8485:2015 + A1 2019 / NHBC (Amber 2) C748 C748 BS8102:2009 RPS178 C753 BBA Agreement Certificate
Radon Bulk Ground Gasses Cardbon Dioxide and Methane VOC Vapour Permeation Hydrocarbons Immersions TYPE-A Bonded Waterproofing Invasive Weed Control SuDs Impermeable Membrane
GP®H 0.6mm

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