Geotextile underlay adds an extra protection barrier to prevent damage to the pond liner from rocks, roots and clay-soil which could puncture the liner. Underlay is highly recommended for every pond installation and should be used at all times under the pond liner. It is also recommended that underlay be used where stones are placed on the liner or around the perimeter. Underlay should be considered when using rubber liners (EPDM) since rubber liners are not resistant to the UV rays of the sun. Rubber liners will tend to dry over a short period of time, if no underlay is placed over them. Most PVC liners are treated for UV and do not usually require protection from the sun.
1 year warranty !