We are frequently asked whether it really is necessary to install a protective pond underlay to protect a pond liner particularly if using a very high quality rubber pond liner. In short, the answer is always ‘Yes, if you want your pond liner to last at least 25 years’ and here are the reasons why this protective underlay is so important in pond construction:

• protects the pond liner from being punctured by rocks and rough edged stones buried in the ground,
• forms a barrier to the potential risk of damage by rodents,
• prevents the liner shifting about due to ground movement,
• protective underlay liners are made from synthetic materials so do not rot or deteriorate over time.

Despite removing as much of the gravel and rocks from the bottom of your pond dug out, earth movement over time will push embedded ones to the surface. Freezing, thawing and the presence of moisture causes the ground to shift. The presence of a protective underlay will form a barrier between the ground surface and pond liner protecting it over time. This ensures a longer life span for your pond.

Carpets, felt and sheets of newspaper can be used as a protective underlay but over time they will start to rot and degrade shortening the life span of the pond.

For a 16 meter square garden pond, a Geotextile protective pond underlay will cost £18.40 in addition to your pond liner and pump order – not much if you consider that your pond, if well cared for will last many, many years.