Installing a geomembrane is a key process in containment and environmental protection projects. From site preparation to welding and quality assurance, each step requires precision to ensure proper performance. In this blog, we will explore the installation procedure, as well as best practices to achieve an efficient and durable installation.

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What is HDPE geomembrane?

HDPE geomembrane, or high density polyethylene, is a type of waterproof barrier material that is manufactured from polyethylene raw material. This material is produced by a blow molding or calendering process, techniques that produce a continuous, uniform sheet. These geomembranes are widely used in anti-filtration engineering due to their excellent chemical and mechanical resistance, which makes them ideal for applications in liquid and waste containment projects. In addition, their flexibility and durability make them a preferred choice for landfill liners, ponds, canals and other structures that require an effective barrier against seepage. The film thickness specification ranges from 0.5 mm to 2.0 mm, allowing it to adapt to different needs and conditions of use, thus ensuring optimum performance in various environmental and industrial applications.

How is the installation of geomembrane?

Installing a geomembrane is a key process in containment and environmental protection projects. From site preparation to welding and quality assurance, each step requires precision to ensure proper performance. Below, we explain in detail the installation procedure, the equipment and techniques used, as well as the best practices to achieve an efficient and durable result.

Soil Preparation

Prior to laying the geomembrane, it is essential to properly prepare the surface. This includes:

• Leveling and compacting the ground to avoid irregularities.
• Removal of stones, branches or any object that may damage the geomembrane.
• Installation of a layer of geotextile if necessary for added protection.

Deployment of the geomembrane

Once the ground is ready, proceed with the placement of the material. This step involves:

• Spreading the geomembrane rolls with specialized equipment.
• Ensure an adequate overlap between panels to facilitate bonding.
• Avoid folds or excessive tensions that could compromise the installation.
• Extend from the bottom to the top position, without over-tightening and leaving a margin of 1.50% for local sagging and stretching.
• Slopes should be placed from top to bottom.
• The longitudinal joints of two adjacent sheets should not be in a horizontal line and should be staggered more than 1 meter.
• The longitudinal joint should be more than 1.50 meters from the dam foot and the bent foot, and should be seated on the plane.
• The principle of placing the slope first and then the bottom of the field should be adopted as far as possible.
• When laying the slope, the direction of film extension should be basically parallel to the large slope line.

Welding and joining of panels

The joints of the geomembrane must guarantee the waterproofing of the system. For this purpose, different welding methods are used:

• Extrusion welding: Thermoplastic material is applied to join the panels.
• Hot wedge welding: The geomembrane layers are melted together using heat and pressure.
• Hot air welding: Used in hard-to-reach areas or for repairs.

Inspection and quality testing

To ensure that the installation is safe and efficient, quality tests are performed, such as:

• Air pressure test: Verifies the tightness of the weld.
• Spark test: Detects possible leaks in joints.
• Visual inspection: Checks for visible defects or irregularities in the installation.

Anchoring and final protection

To avoid displacement, the geomembrane must be properly anchored. This can be done by means of anchoring trenches or ballast systems. In some cases, a top protection layer is added to prolong its service life.

Common HDPE Geomembrane Applications

Slope placement

Before placing the anti-seepage geomembrane on the slope, the placement area is first checked and measured. According to the measured size, the anti-filtration membrane with the appropriate size is transported to the anchor trench platform of the first phase. When laying, according to the actual site conditions, a convenient “push paving” method is adopted from top to bottom. It should be reasonably cut into the fan-shaped area so that the upper and lower ends are firmly anchored.

Laying of floors

According to the measured size, the geomembrane with the corresponding size is transported to the corresponding position. During laying, it is manually “pushed” in a certain direction.

The placement of the geomembrane on the landfill, either on the slope or on the bottom of the site, should be smooth and straight to avoid wrinkles and undulations, ensuring that the two geomembranes are aligned and properly overlapped. The width of the overlap is generally about 10 cm, depending on design requirements.

Precautions when installing geomembrane

1. Before laying the HDPE geomembrane, there should generally be a corresponding acceptance certificate for civil engineering.
2. Before cutting the HDPE film, its relevant dimensions should be accurately measured and then cut according to the actual size. Generally, it is not suitable to cut according to the size shown in the figure. It should be numbered one by one and recorded in detail in the special table.
3. In laying the HDPE geomembrane, the minimum number of seams should be sought, and the raw material should be saved as much as possible under the premise of quality assurance. In general, in corners and deformed areas, the seam length should be shortened as much as possible.
4. Except for special requirements, on slopes with a slope steeper than 1:6, there should be no welds with a horizontal angle of less than 45 °C within 1.5 meters from the top of the slope or the area of stress concentration.
5. During the laying of HDPE film, artificial wrinkles should be avoided. When laid in winter, it should be tightened and paved as much as possible; when laid in summer, it should be properly relaxed.
6. After laying the HDPE geomembrane, walking on the geomembrane surface, handling tools, etc. should be minimized. Any objects that may damage the HDPE geomembrane should not be placed on the membrane or carried over the membrane for walking, so as not to damage the HDPE geomembrane. Accidental damage to the membrane.
7. After laying the HDPE geomembrane, the seams or anchoring edges should be pressed with sandbags in time.

Geomembrane installation is a technical process that requires experience and precision. Following proper procedures and performing quality tests ensures an efficient and durable system. At SAI we have the equipment and experience necessary to offer reliable solutions in the installation of geomembranes, ensuring the protection and containment of industrial and environmental projects.