Pond underlayment is the protective layer installed beneath your pond liner. This non-woven geotextile fabric cushions the liner against rocks, roots, and sharp objects in the soil — preventing punctures that can be difficult and expensive to locate and repair. Every professional pond builder uses underlayment, and Play It Koi strongly recommends it for every installation.
Installation Guide
Lay underlayment directly on the prepared excavation, overlapping seams by at least 6 inches. It does not need to be glued or taped — the weight of the liner and water holds it in place. Use enough to cover the entire area beneath the liner, including shelves and walls. Pro tip: use a double layer of underlayment on rocky or root-heavy ground. At roughly $30–50 per roll, it is the cheapest insurance policy for a liner that may cost hundreds or thousands of dollars.
Play It Koi offers free shipping on orders over $99. Questions? Contact our pond experts for underlayment sizing.
