Pond Underlayment - 10' x 15'

Pond underlayment is installed before the liner in order to prevent punctures that may occur from rough or rocky ground.  The underlayment serves a couple of purposes.  First and foremost it is protection for the pond liner to keep leaks and holes from forming.  It allows the ground to "breath" from underneath - often gases from the earth can get trapped causing the liner to be pushed up into the pond.  The underlayment keeps this from happening.