Established for 20 years, Landline Ltd specialises in the supply, installation and design of gas membranes and gas venting systems for protection against methane, radon and carbon dioxide in domestic housing and commercial buildings.
Landline's quality assured products and services are backed by extensive technical experience.
The company has a working alliance with Visqueen and is their recommended installer for welded gas membranes in the UK.

• Warranted design
Landline offers a fully warranted design service for the gas membrane and gas venting package. The designs take full account of site investigation reports, meet the requirements of the DETR document 'Passive venting of soils and gases beneath buildings', and are backed by professional indemnity insurance. The systems additionally comply with BRE documents 211, 212, 414 and CIRIA report 149.

• Gas membrane types
Two types of gas membrane are offered, each developed for specific applications:
Landflex ZR is a high performance, reinforced aluminium foil polyethylene composite. It is used in domestic housing and high ground gas situations.
Landflex HC is a specially formulated high strength, low permeability modified HDPE. It is used in conjunction with gas venting systems in the construction of steel-framed buildings.

• Pre-welded gas membranes for domestic housing
The Landflex ZR membrane can be pre-welded into panels sized to suit individual house plots. This removes the necessity of on-site sealing of rolls and enables rapid installation in all weather conditions. Housing developers requiring panels of varying sizes at different times can place orders for a complete phase development at the outset, thus achieving best cost. Individually sized panels can then be called off to suit the build programme.

• Gas membranes for steel-framed buildings
The Landflex HC gas membrane is available in a gauge range of 0.5-2.0mm and is manufactured in 6m widths for rapid installation. In gauges of 1.0mm and above, the material is robust enough not to require the use of protection boards or blinding layers. It is also sufficiently strong to enable direct tracking of concrete trucks without damage, allowing for faster concrete pours. This, coupled with Landline's ability to install large welded areas quickly and to perform efficient detail work, makes the system ideally suitable for use by laser screeding companies.

Installation
The company is CITB registered and provides a quality assured installation service using experienced, full time installation crews and high performance hot wedge welding equipment. Crews are CSCS card holders, TWI welding certified and trained in all areas of membrane detail work, including fixing and sealing to pipes, sumps, stanchions, pile caps and perimeter edging.

Technical support
Landline works closely with architects, engineers and contractors, and can provide standard and job specific arrangement drawings for all detail areas of the gas barrier system. Model specifications for the gas membrane and gas venting system package can be provided on request.

Landline provides full gas venting design services including provision of design certificate, drawings and calculations, PI insurance and warranty. The company has in-house CAD facilities and is used to working to deadlines for planning, building control and construction purposes.

• Building structure and floor slab parameters
Landline has extensive knowledge of building works and a full understanding of the differing types of building structure and floor slab design that may be incorporated. This knowledge is vital in providing an engineered gas venting design that is cost-effective, practical and buildable.

• Building control technical support
The company regularly assists in overcoming problems relating to methods of construction and building control and is frequently called in at short notice to provide fasttrack solutions to situations where the use of a gas membrane or a gas venting system had not been considered until after building work commenced.

• Gas venting system component supply
Landline designs, manufactures and stocks their own ZR range of gas venting components suitable for all internal and external venting requirements. Items include: Ventflow geocomposite; vent boxes and lids; radon sumps; gas venting stacks and bollards; aspirating cowls and attachments; periscopic airbrick vents; slotted and standard pipework; geocomposite coupler tees; cross vent connectors; bends, tees and couplers; high strength invert adjustable bollards; stainless steel covers, frames and attachments. All items are designed to be compatible and to work together to form a complete gas venting solution. Components are available ex stock and may be supplied singly or as a package to experienced contractors wishing to install the system themselves.

• Manufacturer certification for self installation
Landline can advise on gas venting component selection and installation and can provide manufacturer inspection training and compliance certification for clients proposing their own installation of the ZR gas venting system.

• Pre-welded gas membrane supply
The company can supply pre-welded Landflex ZR panels to house builders and developers. Panels are pre-welded in factory controlled conditions and are sized and shaped to suit individual house plots. This removes the necessity of on-site jointing of rolls and enables rapid installation in all weather conditions. Housing developers requiring panels of varying sizes at different times can place orders for a complete phase development at the outset, thus achieving best cost, and can then call off individually sized panels to suit the build programme.

• Gas-resistant jointing tape, top hats
and DPCs
The company can offer a full range of self installation accessories to accompany the pre-welded Landflex ZR gas membrane. These enable straightforward sealing to pipe and service entries and connection to the DPC.

• Contractor training: gas membrane installation
For housing developers placing phase development orders, the company offers a free on-site training programme covering all installation methods and techniques. These include sub base preparation, positioning of panels attachment to the DPC, sealing to pipe entries and avoidance of membrane damage during overlay operations.