Pool Wall Foam 1/8 inch thick x 48 inches high x 105 feet long protects against punctures to your pool liner. Create a smooth wall surface with this closed-cell foam padding that helps prevent rust, corrosion and other wall degradation. It keeps your liner looking like new for years to come. Wall foam is a 1/8″ thick foam mat that protects your liner from constant friction against your pool wall, preventing tears or punctures.