Pond Liner Underlay

CascadeKoi & Aquatics Highly recommends using Gordon Lowe underlay. Instead of using heavy sand, which stones and roots can penetrate, it is essential to use underlay with all liners. Liner Underlay is made from a woven material which is rot resistant and extremely difficult for sharp objects and roots to penetrate. Using an Liner underlay should ensure that you have no surprise holes appearing in your liner, requiring awkward repairs or expensive replacement.

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We strongly recommend that our polyester Pond Liner underlay material is used beneath a flexible liner, not only to help protect it from puncture by sharp stones, roots etc, but also to stabilise soft sub-soils and reduce excessive localised stretching of the liner.

Rubber Pond liners are protected from mechanical damage by using a geotextile underlay between the pond liner and ground surface. Geotextile matting is also usually specified on top of the liner when building brick or concrete structures and when gravel and stones are to be used, for example in a wildlife pond beach area.

Cascade supplies Pond Underlay which are mechanically bonded, non-woven geotextiles, made of UV stabilised polypropylene. These geotextiles offer exceptionally high performance and provide a highly effective protective barrier between substrate and liner. We recommend that our underlay is used beneath all our liners, not only to help protect liners from penetration by sharp stones, roots, etc, but also to reduce excessive localised stretching of the liner when ground settlement occurs beneath the liner.

These materials are actually developed for commercial road building and ground stabilisation applications and are far superior to cheaper underlay felts. Our 50 years trading experience reinforces our belief that quality pond building begins with selecting high quality products from the industrys leading suppliers. Using cheaper materials with a lower grade specification could potentially lead to a liner failure in years to come. We suggest fitting the best Underlay your budget allows. We offer two grades, Polyfelt TS60 -260gsm being the higher specification material.

In order to address the relatively high cost of underlay material when installing a pond liner to a lower budget, we also offer the lighter duty Polyfelt TS40 - 180gsm underlay. This material is also a more economical choice for much larger ponds and lakes when used in conjunction with good soil conditions and sand blinding etc.