HEISSNER Pond Underlay

For biotopes, garden ponds and compact fish ponds

A pond underlay effectively protects the pond liner from damage caused by stones, roots, and uneven surfaces. Serving as a base layer in pond construction, a HEISSNER pond underlay enhances the stability and longevity of garden ponds, koi ponds, and biotopes. Made from tear-resistant material, these pond underlays are designed for permanent outdoor use and are compatible with both PVC and EPDM pond liners.

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Pond Underlay: 10 items

Heissner Stone Liner, 0.4 x 2.5 m / 1 m²

Heissner Stone Liner, 0.4 x 2.5 m / 1 m², Thickness: 5.0 mm

  • UV-resistant
  • Fully eco-friendly
  • Colour: Light sandstone
CHF 37.50

Delivery by October 30

 Extra Strong Pond Underlay 2 x 3 m / 6 m²

Heissner Extra Strong Pond Underlay 2 x 3 m / 6 m², 200 g/m² / Thickness: 1.0 mm

  • Ideal for stony ground & high water pressure
  • Rot-proof & frost-resistant
  • Compatible with PVC & EPDM pond liners
CHF 29.50

Delivery by October 30

 Extra Strong Pond Underlay 4 x 4 m / 16 m²

Heissner Extra Strong Pond Underlay 4 x 4 m / 16 m², 200 g/m² / Thickness: 1.0 mm

  • Ideal for stony ground & high water pressure
  • Rot-proof & frost-resistant
  • Compatible with PVC & EPDM pond liners
CHF 59.50

Delivery by October 30

 Extra Strong Pond Underlay 3 x 4 m / 12 m²

Heissner Extra Strong Pond Underlay 3 x 4 m / 12 m², 200 g/m² / Thickness: 1.0 mm

  • Ideal for stony ground & high water pressure
  • Rot-proof & frost-resistant
  • Compatible with PVC & EPDM pond liners
CHF 49.50

Delivery by October 30

 Heissner Stone Liner, 0.6 x 2.5 m / 1.5 m²

Heissner Stone Liner, 0.6 x 2.5 m / 1.5 m², Thickness: 5.0 mm

  • UV-resistant
  • Fully eco-friendly
  • Colour: Light sandstone
CHF 49.50

Delivery by October 30

 Weed Stop Weed Suppressant Membrane, 100 x 1 m / 100 m²

Heissner Weed Stop Weed Suppressant Membrane, 100 x 1 m / 100 m², 120 g/m²

  • Protection from weeds & roots
  • Permeable to air, water and nutrients
  • Not UV-resistant
CHF 296.00

Free delivery by October 30

 Heissner Stone Liner, 0.6 x 15 m / 9 m²

Heissner Stone Liner, 0.6 x 15 m / 9 m², Thickness: 5.0 mm

  • UV-resistant
  • Fully eco-friendly
  • Colour: Light sandstone
CHF 371.00

Free delivery by October 30

 Weed Stop Weed Suppressant Membrane, 200 x 1 m / 200 m²

Heissner Weed Stop Weed Suppressant Membrane, 200 x 1 m / 200 m², 50 g/m²

  • Protects against stubborn weeds
  • Permeable to air, water and nutrients
  • Not UV-resistant
CHF 256.00

Free delivery by October 30

 Heissner Stone Liner, 0.4 x 15 m / 6 m²

Heissner Stone Liner, 0.4 x 15 m / 6 m², Thickness: 5.0 mm

  • UV-resistant
  • Fully eco-friendly
  • Colour: Light sandstone
CHF 237.00

Free delivery by November 17

 Heissner Stone Liner, 1 x 12 m / 12 m²

Heissner Stone Liner, 1 x 12 m / 12 m², Thickness: 5.0 mm

  • UV-resistant
  • Fully eco-friendly
  • Colour: Light sandstone
CHF 444.00

Free delivery by November 17

Which pond underlay should you choose?
The right option depends primarily on pond size, the ground conditions and required material thickness:

  • 200 g/m² · 1.0 mm thickness - suitable for smaller garden ponds with a level, sandy base
  • 200 g/m² · 3.0 mm thickness - recommended for stony subsoil, larger ponds or koi ponds

Selecting the appropriate thickness ensures reliable protection for the pond liner and creates a stable, long-lasting pond structure.

How long does a pond underlay last?
A pond underlay is designed for permanent outdoor installation:

  • rot-resistant, water-resistant and frost-resistant
  • when properly installed, it remains fully functional for 10–20 years or more

A carefully prepared, level base enhances its protective performance and further extends its service life.