Should You Put Foam Under A Pool?

Many pool owners believe that adding a foam product beneath their swimming pool liners, such as Happy Foam Bottoms and Gorilla Pads, will soften the pool floor, making the bottom more comfortable to walk on while swimming. 

And in some cases, this may be so; however, there is a major problem with foam under a pool.

Why Foam Isn’t Always the Best Option For Under Pool Liners

When you put foam padding under a pool, they cause serious cleaning problems and become a headache after installation.

After installing your swimming pool liner and filling the pool with water, the pool liner gets sucked into the groves and indentations of the foam padding. This happens because the water applies pressure to the pool liner, helping it take the shape of your pool. 

As a result, whether you own a beaded pool liner or an overlap pool liner, this creates a severe cleaning problem. You will begin to notice the growth of algae, mold (black, green, and brown), and even fungus.

Even though you may think you can just clean it with chemicals and a scrub mitt, there is a bigger problem at play. The algae, mold, and fungus becomes embedded under the pool liner between the foam paddings and the pool liner in all areas where the foam padding was installed.

Let’s not forget that this gross health hazardous fungus can spread throughout the pool liner to parts where the foam isn’t installed. 

Algae, mold, and fungus are more noticeable near foam installation areas. The only safe way to clear pools of algae and fungus is to remove the hazardous foam mats under the pool and install a replacement pool liner.

A Better Alternative: Polyester Geotextile Liner Pads

LinerWorld offers premium liner pads made from Polyester geotextile fabric. These protective pads are engineered specifically for above ground pool protection. 

Learn More About Liner Pads

Tear & Puncture Resistance

Our liner pads act as a protective barrier between your liner and the ground, guarding against sharp stones, roots, undergrowth, and other hazards that can puncture your liner and lead to costly damage.

No Shifting or Seams

Unlike foam sheets that must be taped together and can separate, our pads are made to cover the entire bottom of your pool in one solid piece and perfectly sized to fit your pool. That means no shifting or gaps that can cause issues down the road. 

Mold & Mildew Resistant

The breathable and waterproof polyester allows moisture to drain away rather than get trapped, preventing mold and mildew buildup, stains, and that funky pool smell. 

Stays Soft, Season After Season

Unlike foam that can flatten out over time with frequent pool use, our liner pads retain their structure and provide reliable cushioning for years. They’re extremely durable tough, yet still soft underfoot.

Pro Tip: Use Foam Cove

While we recommend using a liner pad when installing in a new pool liner, we also highly recommend adding a foam pool cove around the base of your pool wall. This rounded edge prevents the liner from stretching too far at the base and helps evenly distribute pressure across your pool.

Last Updated: June 13, 2025