Heavy-Duty Pond Underlayment, 5' x 10'

The Aquascape Heavy-Duty Pond Underlayment 5' x 10' (1.5 m x 3 m) is a non-woven geotextile fabric that protects EPDM pond liner from puncture damage caused by sharp rocks, roots, and subsurface debris. Lay it between the excavated ground and the liner before filling to reduce the risk of liner failure at the pond floor and side walls.

Protection Layer That Extends Liner Life

EPDM liner is strong and flexible, but it is not puncture-proof against sharp substrate objects that shift under the weight of water. Underlayment distributes load across a broader area, cushions the liner against point contact, and blocks roots from growing up through the liner after installation. The 5' x 10' size suits small to medium pond floors, koi pond side wall protection, and rock stream sections where individual pieces are easier to manage than a large roll.

How to Use

Clear the excavation of sharp rocks and protruding roots before laying underlayment. Unroll the piece over the prepared substrate, pressing it into contours. Overlap seams by at least 6" (15 cm) where multiple pieces meet. Lay EPDM liner on top and fill the pond to seat both layers against the excavation profile. Underlayment does not need to be secured before liner installation.

Ideal for small backyard ponds, decorative koi features up to 1,500 gal (5,700 L), and waterfall stream sections where cut-to-length pieces are more practical than a full roll.