SUP-01Self-sealingNo welding

GCL 4500 clay liner

Needle-punched bentonite liner, 4m × 50m rolls

Product shown for illustration — spec above is definitive

Granular sodium bentonite needle-punched between a woven and a non-woven geotextile. Once it's confined under its cover layer and hydrated, the bentonite swells into a very low-permeability barrier that seals small punctures on its own. Rolls are overlapped rather than welded, so there's no welding plant on site.

Roll: 4m × 50m · 200m²
Mass: 4,800g/m²
Jointing: Overlapped, no welding

SUP-01 / OrderDirect from manufacturer

Supplied as

Quantity — rolls

= 200m² total

Quantity breaks

5+ £1,269.60 per roll

Total ex VAT

£1,483.20

£1,779.84 inc VAT

Ask us to price it installed

SKU: AQ-GCL4500-4X50
Lead time: Confirmed with your order
Carriage: Included
Sold: per roll

Specification

Construction: Granular sodium bentonite between woven and non-woven geotextiles, needle-punched
Mass per unit area: 4,800g/m²
Thickness: 6.8mm
Permeability: ≤5.0 × 10⁻¹¹ m/s
Roll size: 4m × 50m (200m²)

Documents

GCL 4500 datasheetMass, thickness, strength and permeability — open datasheet ↗

Datasheets and certificates are issued with every delivery. Need them before you order? Ask and we'll send them over.

What you get

Full roll in the size selected
Manufacturer's datasheet

Where it's used

SuDS ponds and pools
Lagoons and containment
Dams, irrigation channels and water transfer

Supply & install

We'll put it in for you.

Buying the parts is one option. The other is handing us the drawing and taking a single installed price — with the welding, test weld and handover documentation included.

GCL pond lining →

Before you order

Frequently asked questions

Yes. A GCL only works confined, so the cover layer should go on promptly after it's laid — don't lay more than you can cover. Bentonite that hydrates before it's confined just swells and washes away.

GCL suits gently sloped ponds and basins with the right water chemistry, where a natural clay bed and simple detailing are an advantage. Steep slopes, exposed edges or aggressive contents usually call for a welded membrane instead.