Waterproof Membrane Geosynthetic Clay Liner

Waterproof Membrane Geosynthetic Clay Liner

The liner for your pond, landfill, dam or lake should be capable of standing up to the coldest and hottest temperatures. Unfortunately many cheap liners are being sold into the price driven market that meet theoretical based laboratory tests but fail when under site conditions.

A geosynthetic clay liner, or GCL, is an engineered composite material that combines the engineering function of sealing against liquids and gases. They are used to replace compacted clay liners and geomembranes.


Wrekin’s geosynthetic clay liner (GCL) is a needle punched composite consisting of two geotextile Waterproof Membrane Geosynthetic Clay Liner layers encapsulating sodium bentonite clay to form a waterproof barrier. This high-performance liner is an ideal replacement for compacted clay as landfill base liners and backfilled seepage control liners. It is a durable lining material with low permeability, high chemical resistance and self-healing capability.

The sodium bentonite in GCL swells when hydrated by water pressure to form a highly impermeable diaphragm. This allows the liner to withstand confining loads, while still providing hydraulic protection similar to that of several feet of compacted clay when hydrated under the same confining load.

GCLs are also more resistant to varying weather conditions, such as freeze-thaw and desiccation-rewetting cycles, that often cause compacted clay liners to crack and increase leakage. Consequently, GCLs require significantly less monitoring and maintenance than conventional liners. Additionally, GCLs are not impacted by changes in moisture content or density as they hydrate, unlike compacted clay liners. This ensures consistent performance and provides greater longevity.


GCLs are designed to withstand shear forces on steep slope applications. They offer superior tensile strength and self-healing capabilities in the event of damage caused by foreign matter penetration or puncture.

The inner layer of a GCL is made up of sodium bentonite. When hydrated, bentonite clay swells to a gel impermeable body, which makes the liner resistant to erosion and provides excellent anti-seepage capability. GCLs are also designed to resist varying weather conditions, including freeze-thaw cycles that can crack and damage compacted clay liners.

As a natural inorganic material, bentonite doesn’t undergo any aging reaction or corrosion, and has Geocell for Roadbed good durability. Moreover, it is non-toxic, harmless to human beings and animals, and has good environmental performance.

A GCL is composed of two needle punched geotextile layers encapsulating a layer of sodium bentonite for sealing applications. The bentonite is embedded in the geotextiles and bonded to the top of the nonwoven geotextile with a composite HDPE liner to provide a high-strength, low permeability solution for landfill, CSG, potable water, wastewater and oil depot containment applications. GCLs are easy to install, requiring no additional bagged bentonite and less labor than traditional compacted clay liners. Additionally, GCLs are resistant to varying weather conditions and don’t require the frequent rewetting that can reduce the hydraulic performance of conventional compacted clay liners.

Structural Strength

Geosynthetic clay liner, also known as GCLs or bentonite waterproof blankets are a type of environmental protection composite lined system. They comprise a woven or non-woven geotextile layer encapsulating a layer of sodium bentonite. This combination provides a high-performance liner that combines the low permeability of bentonite with the tensile strength and chemical stability of geotextiles or geomembranes.

The shear strengths of GCLs have been assessed under a wide range of loading conditions, including monotonic and cyclic load tests. GCLs have been shown to be highly resistant to shear forces. This is important because waste disposal facilities are often constructed in seismic regions, where the shear capacity of liners is particularly important.

In addition to their high shear strength, GCLs have excellent mechanical properties. Their pore structure is very small, which makes them highly water-swelling and self-healing. This enables them to repair small damage caused by installation, ground settlement, concrete shrinkage and seismic activity.

In addition, their natural sodium base bentonite doesn’t oxidise with time or with changes in the surrounding environment, which means they don’t have to be replaced as frequently as compacted clay liners. Furthermore, GCLs are easy to install as they don’t require any primers, adhesives or tapes. This saves money in terms of labor, material and storage costs. The GCL’s shear capability makes it an optimal solution for steep slopes, and its resistance to fluctuating weather conditions is another benefit.

Environmentally Friendly

GCL is a factory-manufactured, reinforced composite hydraulic barrier consisting of a combination of durable geosynthetic textiles needle-punched together enclosing a layer of natural sodium bentonite clay. Upon hydration, the bentonite material swells to form a low-permeability clay layer which provides superior moisture and antiseepage capability.

When compared to traditional thick compacted clay liner, GCL can be installed up to 700m2 per day and is compatible with most construction materials. This means that the waterproofing membrane is able to be laid over a concrete mud slab, eliminating the need for costly formwork. This saves on labour and material costs, while also providing a quicker and safer installation.

Water penetration and seepage are common problems in apartment buildings. If left untreated, they can lead to mould growth, discolouration and rotting of building structures. It is essential that the correct waterproofing membrane is used during construction to protect against these problems. This is why it is important to consider the environmental friendly and cost efficient qualities of Geosynthetic Clay Liner.