Does the Classic or Premium RPE Liner require an underlayment like EPDM?

In most cases, if going over smooth sand, soil or clay, the Premium RPE Liner does not require an underlay because of its increased puncture resistance, whereas EPDM is softer and therefore usually needs one to prevent tears and punctures, as well as to qualify for the warranty. An underlay is still a good idea with RPE if going over abrasive surfaces like concrete or prickly rock slabs like granite.

The Premium RPE liner is highly puncture-resistant and tough. However, it is important to remember that once the water is added to the pond, it will push the liner down into the ground with tremendous force. It is very important to make sure there are no sharp objects below the liner to prevent punctures. For added protection, it is always recommended to use a geotextile underlayment in environments with abrasive surfaces to further reduce the risk of punctures. We recommend our high-quality Pond Liner Underlay, which can be used underneath or over top of a liner.