Gorilla or Gradon Foam on the whole pool Underground


New member
Jun 18, 2018
I have a new liner that will be installed in the next few days (if he shows) and i have had to repair some sand walls and floors (cement like) from erosion. Using pool cement, the job is less than perfect so I want to use a foam roll on the entire pool , walls slopes and floor.

Anyone have an opinion? GLI pool liners would not give advice to use or not and my dealer, is just , "it's your pool"- cop outs......

To protect the walls from every eroding again we put on a urethane binder so there is now a "liner" going to be under the liner.

Thank you in advance for comments!


In The Industry
Jul 21, 2014
If it’s an inground, a membrane in the floor will be nothing but problems from visible mold, buoyancy, double membrane displacement & won’t protect your sub base.

It’s your pool- is not an unreasonable retort; but short & curt yes; if that was the extent of dialogue.

Not GLI place to comment on backyard engineering either.


TFP Expert
Bronze Supporter
In The Industry
Aug 10, 2017
Morris Cnty NJ
I would leave it with the " binder" you have on it and just foam the walls if you like the feel. Anything under the floor with groundwater issues will show through and wrinkle as poolguy said. The base doesn't have to be perfect it only looks bad under the lights at night. Every pool I've seen looks like the moon at night lol