MEMBRANES 164

Membranes

The building regulations (Approved Document C) require that appropriately designed precautions should be incorporated into allnew development where the potential for the ingress of hazardousgases is a concern. Common causes of their presence includebrownfield sites, landfill and natural occurrence such as peat.

EH Smith are able to provide a selection of gas protection productsthat ensure we can offer the optimum solution in the safe dilutionand dispersal of the following hazardous gases:

• Methane (Ch4)• Carbon Dioxide (Co2)• Radon (Rn)• Hydrocarbons

MEMBRANES

CORDEN EPS RADON MEMBRANE (RN)

165 MEMBRANES

Radon is a naturally occurring radioactive gas formed by the breakdown of uraniumand radium. It is crucial that when gas protection is required, the site conditions,design and application are all taken into consideration to provide an impermeablemembrane, protecting the most valuable asset, “the building” against the gases thatcan cause future problems.

The acceptable level of Radon which has been regarded as the “safe” threshold untilrecently has been 200Bq/m3 (Bequerols per cubic metre) however, more recent studieshave proven that exposure to radon at levels between 100 and 200Bq/m3 is ashazardous, prompting the following questions by The Health Protection Agency.The effectiveness of polythene sheeting is being questioned, particularly when it isformed from recycled material.

Should the industry be consideringa more robust, virgin polymer material of greater thickness?

• In known radon affected areas, should the installed protective measures be inspected by Building Control Bodies?

• In known radon affected areas, should a percentage of newly built propertiesbe post inspected?

• Would the use of a Radon Sump eliminate many of the problems caused by membrane failure?

This blend gives the product immense strength, tear and puncture resistance whencompared to ordinary DPM and other radon membranes. Because of it’s integralstrength, it has no need for reinforcement and thus makes it suitable for use as a proprietary gas/damp proof membrane where resistance to puncture is key.Corden EPS Radon Membrane prevents the transmission of unacceptable levels ofharmful gases and due to the nature of it’s construction, the membrane overcomesproblems associated with recycled products, such as imperfections.

Advantages• Suitable for use on sites contaminated with higher concentrations of Radon• Co-extruded virgin co-polymer. Zero imperfections• 4 metre wide uni-fold membrane• Premium DPM/vapour barrier• Extremely tough with excellent resistance to tear and puncture• Compatible with vented systems

Product SpecificationCorden EPS Radon Membrane is a co-extruded, co-polymer hybrid.

Physical Description Test method Value/Units

Thickness 300mu/1200 gaugeWeight 276g/m2Colour Red and black. Co-extruded.Standard roll width 4mTechnical PerformanceTensile strength MD 24mpa

CD 21.5mpaElongation at max load MD 1436%

CD 1600%Dart impact strength <1kgLow temperature flexibility -70ºc no effectRadon permeability 6.7x10-12m2.sMoisture Vapour transmission 0.31g/m2/day

MEMBRANES

CORDEN EPS METHANE MEMBRANE (CH4)

MEMBRANES 166

Methane is a colourless, odourless, flammable gas formed as a by-product of organicmaterial breaking down. It is crucial that when gas protection is required, the site conditions, design and application are all taken into consideration to provide an impermeable membrane capable of surviving installation and subsequent traffic to protect the most valuable asset “the building” against harmful gases that can cause future problems.

The Corden EPS Methane Membrane prevents the transmission of unnaceptable levelsof dangerous gases and due to the the nature of it’s construction and it’s resisitance todamage, it overcomes problems associated with membranes of a lesser gauge.

The Corden EPS Methane Membrane is a high quality, very flexible polyethylene(LLDPE/VFPE) geomembrane produced from specially formulated, virgin polyethyleneresin designed specifically for flexible geomembrane applications. The high uniaxialand multiaxial elongation characteristics of Corden EPS Methane Membrane make itvery suitable for applications where a flexible, robust membrane meets the specification.

Corden EPS Methane Membrane is available in standard roll sizes of 5.9m x 50m or 2.95m x 50m. Several denominations of these sizes are available.

Advantages• Suitable for use on methane contaminated sites • Excellent resistance to chemicals and UV radiation• Excellent weld characteristics • Very high resistance to puncture and tear• Low permeability to methane • Available 5.9m wide• Compatible with vented systems • All sundries available

Product Specification

Physical Description Test method Value/Units

Thickness ASTM D 5199 0.75mmDensity ASTM D 792/1505 A 0.92g/cm3 (min)Colour BlackStandard roll width 5.9/2.95mTechnical PerformanceElongation at break G.L.(50mm) 800%Puncture resistance ASTM D 4833 195NTear Resistance ASTM D 1004 70NLow temperature brittleness ASTM D 746, Cond B -77ºcMethane permeability 2.0x10-6 ml/cm3.sMoisture Vapour transmission 107x10-9ml/cm3.s

MEMBRANES

CORDEN EPS HYDROCARBON MEMBRANE (CH)

167 MEMBRANES

Hydrocarbons are colourless gases formed as a by-product of decomposing organic matter.

It is crucial that when gas protection is required, the site conditions, design and application are all taken into consideration to provide an impermeable membranecapable of surviving installation and subsequent traffic, to protect the most valuableasset “the building” against harmful gases that can cause future problems.

The Corden EPS Hydrocarbon Membrane is a high quality, high density polyethylene(HDPE) produced from specially formulated, proprietary virgin polyethylene resindesigned specifically for flexible geomembrane applications.

The Corden EPS Hydrocarbon Membrane has outstanding chemical resistance,mechanical properties, environmental stress crack resistance, dimensional stability and thermal ageing characteristics. The Corden EPS Hydrocarbon Membrane also hasexcellent resistance to UV radiation and is suitable for exposed conditions.

The Corden EPS Hydrocarbon membrane is available in standard roll sizes of 5.9m x 50m or 2.95m x 50m. Several denominations of these sizes are available.

Advantages• Suitable for use on hydrocarbon contaminated sites • Excellent resistance to chemicals and UV radiation• Excellent weld characteristics • Can be taped (Consult technical department)• Very high resistance to puncture and tear • Low permeability to hydrocarbon gases• Available 5.9m wide (Consult separate data sheet)• Compatible with vented systems • All sundries available

Product Specification

Physical Description Test method Value/Units

Thickness ASTM D 5199 1mmDensity ASTM D 792/1505 A 0.94g/cm3(min)Colour BlackStandard roll width 5.9/2.95mTechnical PerformanceElongation at break G.L.(50mm) 700%Puncture resistance ASTM D 4833 320NTear Resistance ASTM D 1004 125NHydrocarbon permeability 2.0x10-6ml/cm3.s

MEMBRANES

CORDEN EPS C02/RADON MEMBRANE (C02) (RN)

MEMBRANES 168

Carbon Dioxide is a colourless, odourless gas formed as a by-product of decomposingorganic matter.

It is crucial that when gas protection is required, the site conditions, design and application are all taken into consideration to provide an impermeable membrane, protecting the most valuable asset, “the building” against the gases that can causefuture problems.

The acceptable level of Radon which has been regarded as the “safe” threshold untilrecently has been 200Bq/m3 (Bequerols per cubic metre) however, more recent studieshave proven that exposure to radon at levels between 100 and 200Bq/m3 is ashazardous, prompting the following questions by The Health Protection Agency.

The effectiveness of polythene sheeting is being questioned, particularly when it isformed from recycled material.

• Should the industry be considering a more robust, virgin polymer materialof greater thickness?

• In known radon affected areas, should the installed protective measures beinspected by Building Control Bodies?

• In known radon affected areas, should a percentage of newly built propertiesbe post inspected?

• Would the use of a Radon Sump eliminate many of the problems causedby membrane failure?

Product SpecificationCorden EPS CO2/Radon Membrane is a blown extruded blend of virgin polymer MDPEand LDPE (co-polymer).

Physical Description Test method Value/Units

Thickness 375mu/1500 gaugeWeight 365g/m2Colour Rust redStandard roll width 4mTechnical PerformanceElongation at max load MD & CD 800%Dart impact strength 1.012kgTear Resistance MD 248N/mm2

CD 303N/mm2Low temperature flexibility -5ºcRadon permeability 4x10-12m2/sCarbon Dioxide permeability 637cc/m2.dMoisture Vapour transmission 0.16g/m2/day

MEMBRANES

169 MEMBRANES

This blend gives the product immense strength, tear and puncture resistance whencompared to ordinary DPM and other radon and CO2 membranes. Because of it’s integral strength, it has no need for reinforcement and thus makes it suitable for use as a proprietary gas/damp proof membrane, where resistance to puncture is key.

Corden EPS CO2/Radon Membrane prevents the transmission of unacceptable levelsof harmful gases and due to the nature of it’s construction, the membrane overcomesproblems associated with recycled products, such as imperfections.

Advantages• Suitable for use on sites contaminated with higher concentrations of CO2 and Radon• Virgin co-polymer. Zero imperfections• 4 metre wide uni-fold membrane• Premium DPM/vapour barrier• Extremely tough with excellent resistance to tear and puncture• Twin wedge or extrusion weld• Compatible with vented systems