GP®4 gas barrier is a multi-layer, low density polyethylene membrane, reinforced with a polypropylene reinforcing grid. GP®4 is specifically designed and manufactured to perform as a radon, air & moisture protection system, as well as low level protection to carbon dioxide and methane.

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Product Benefits

  • Manufactured to perform as a Radon, air and moisture protection system.
  • Provides a low-level protection to Carbon Dioxide and Methane.
  • BBA approved and CE marked.
Product Description

GP®4 is a high quality proprietary gas resistant damp proof membrane, manufactured from low density reinforced polyethylene (LDPE). This products is ideal for use on sites where ground gas contamination is present.

Should be used on any site where radon gas is present. The barrier is sufficiently resistant to the ingress of radon into a building. On more heavily contaminate sites as passive or active venting system may be required to dilute the gasses down to acceptable levels and specific design advice should be sought.

Size3000 x 33 000 x 0.6 mm
Warranty Description60 Year minimum
Uniclass 2015Pr_25_57_65_60
CAWSJ40/145 Loose laid weldable polyethylene gas retardant damp proofing
J40/140 Loose laid plastics or rubber sheet gas retardant damp proofing
D21/350 Gas-retardant membrane
PurposeGas retardance.
Damp-proof membrane.
StandardTo BS EN 13967.
Also to BRE BR211.
Performance characteristics
Tensile strength (minimum)570 N/50 mm.
Tear resistance500 N.
Elongation to break15%.
Resistant to underground gasesRadon - 1.7 x 10(-11).
Third-party certificationBritish Board of Agrément (BBA) Certificate No. 20/5728 (P5).
CE Mark - EN 13967.
FormLow density polyethylene membrane with reinforcing grid.
Weight400 g/m².
Thickness0.6 mm.
Width2 m.
Roll length (minimum)50 m.
Recycled Content0%
CharacteristicsTest MethodUnit
Water ColumnEN 20811PASS
Water Vapour Transmission - Moisture Resistance FactorEN 1931130 m
Water TightnessEN 1928 (A)PASS
CharacteristicsTest MethodUnit
Resistance to Static LoadEN 12730-B20 kg
Tensile Strength (MD)EN 12311-1600 N/50mm
Tensile Strength (CMD)EN 12311-1570 N/50mm
Tensile Elongation (MD)EN 12310-1 15%
Tensile Elongation (CMD)EN 12310-1 15%
Puncture ResistanceEN 122361.25 kN
Resistance to Tearing (Nail Shank) MDEN 12310-1500 N
Resistance to Tearing (Nail Shank) CMDEN 12310-1500 N
CharacteristicsTest methodUnit
Radon diffusion co-efficient (D)ISO/TS 11665-138.0 x 10-12 m2/s
Radon diffusion co-efficient (D) JointISO/TS 11665-137.4 x 10-12 m2/s

GP®4 can be used on any site where Radon Gas is present. The barrier is sufficiently resistant to the ingress of radon into a building. On more heavily contaminated sites a passive or active venting system may be required to dilute the gases down to acceptable levels and specific design advice should be sought.

JUTA UK – radon, ground gas, vapour, air and moisture barrier characteristic properties:

  • High Chemical Resistance
  • High resistance to Ground Gasses
  • Long Term Durability (Performance guaranteed for the lifetime of the building)
  • Compatible with all building materials
  • Manufactured to meet the most up to date British Standards and guidance.

JUTA GP®4 should be installed in accordance with the product installation guidelines and in accordance with best practice.

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.

Roll weights can be in excess of 20kg and hence appropriate care and equipment is required for unloading and handling.

Rolls of JUTA GP®4 should be stored on stable/ level ground and stacked not more than five rolls high, with no other material stacked on top. The rolls can be stored outdoors when packaged but should be protected from exposure to UV.

CE Mark
CE Mark - EN13967:2012
NHBC Standards Compliant
BBA Certificate 20 5728
BBA Certified - Certificate No. 20/5728 (P5)

BIM objects are digital descriptions of products or materials that, when combined with other BIM objects create a Building Information Model. These downloadable files can be used for these purposes.

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 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
  • The 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
  • A 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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