ISO 9001:2000 Geomembrane Installation Guide

General
To ensure that complete watertightness is achieved, installation is carried out by our own fully trained personnel.

All matters relating to material specification and thicknesses are agreed prior to contract.

All construction details are agreed prior to commencement of work.

Requirements in Respect of the Surfaces to be Lined
All surfaces on which the lining is to be laid, must be prepared so that no damage to the lining is possible.

The surface shall be free of all rocks, sticks, stones, roots, sharp objects or debris of any kind. The surface should provide a firm unyielding foundation for the membrane with no sudden, sharp or abrupt change or break in gradient. No standing water or excess moisture shall be present. The surface must be constructed to allow the necessary compaction. 90% proctor with a surface tolerance of ±25mm for plastic materials, 80% proctor and ±50mm for rubber materials.

If after inspection of the surface to be laid on it is deemed unsuitable, sand blinding or an approved geotextile may be required as a protection layer.

Water Table
The water table level should be established and if higher than the base of the excavation adequate drainage should be installed to prevent water pressure build up below the liner.

Transport and Storage of the Sheet
The liner is provided in rolls or panels weighing up to 1.5 tonnes. On site it can be stored on a flat area in the open.

Installation of Linings
Before lining work begins, all surfaces to be lined have to be approved by Butyl Products Site Supervisor.

The laying of the sheet is carried out in three steps:

• Positioning and unfolding of the panels.
• Welding of joints.
• Connections to concrete structures, pipe penetrations, sumps, anchor trenches etc.

The lining work is carried out in accordance with an agreed installation programme. On-site progress of the lining work, as well as the climatic and working conditions are recorded, and on completion a lay-out plan is prepared to record the location and sizes of each panel of sheeting.

Positioning of Lining Panels.
Positioning of sheeting is undertaken by machinery or hand. Special care is necessary not to damage the surface to be lined. After unrolling the sheeting, its position is adjusted so that a suitable overlap is achieved for the welding process. Before welding the sheet it is checked for any damage.

Environmental Conditions Limiting Lining Works
No welding can be carried out where temperatures are below 4°C or above 30°C or in damp conditions of any kind. Sheet laying can become dangerous when wind speeds exceed 10km/hr.

Joining of the Panels
For plastics: The welding techiques used are the heated split wedge open channel or extrusion welding.
For rubbers: The hot platen vulcanising system is employed.
All welds are 100% tested.

Testing of the Weld Joints
The non-destructive test of each weld is carried out by our operators. The test procedures are as follows:

• The split wedge open channel joint is air-pressure tested.
• The extrusion joint is tested by the copper wire / spark test method.
• Vulcanised joints are air lance or vacuum box tested.

For destructive testing, a check of the welded joints mechanical properties is carried out by taking samples of a joint from installation in progress and checking the welds bonding strengths in tensile and peel.

Constructional Details
We enclose illustrations of our standard fixing details. We will recommend designs for any special detail that a project may require and submit them for approval by the project designers prior to commencement on site.

Protective Cover
If after inspection of the material which is to be placed on top of the liner, it is deemed to be unsuitable, a non woven geotextile may be recommended as a protective layer.

Installation of a protective layer should be carried out after acceptance of the tested liner. Any protective cover should be placed by a front end loader always pushing out and running on at least 500mm thickness of the deposited material and not travelling directly on the lining.

The protective cover shall be spread in a manner, to ensure that the liner follows the contours of the ground and no bridging or stretching of the material occurs.

Should the covering operation cause damage to the liner, our engineers should be informed immediately. They will carry out any necessary repairs and advise on actions to prevent recurrance.

Health and Safety - General Statement of Policy
Our Policy is to provide and maintain safe and healthy working conditions, equipment and systems of work for all our employees and to provide such information, training and supervision as they need for this purpose. We also accept our responsibility for the health and safety of other people who may be affected by our activities.

This general statement of Policy is supported by 17 sections of detail in the full Health and Safety Policy which is available on request.

Risk Assessments and Method Statements
Site specific risk assessments and method statements are prepared for each contract.

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