Foam Insulation for a Squeaking Acrylic Tub Installation

The proper method for installing an acrylic or plastic shower pan or bathtub is to install the pan or tub in a base of mortar, as per the installation instructions.
Spraying foam can temporarily fix a squeaking acrylic tub.Spraying foam can temporarily fix a squeaking acrylic tub.
Not every do-it-yourselfer follows the installation instructions properly, however, and in the cases where not enough mortar is used or no mortar is used at all, you will be left with a tub that squeaks every time you enter or exit the tub due to excessive movement. A quick fix is to use a spray-on foam insulation to help bolster the tub’s base.

Step 1

Determine where the tub is squeaking, as this will be the point that needs reinforcement. You can either do this by walking in the tub slowly to determine the point of origin or by having someone else walk in the tub while you look under the tub around the edges to see where it is flexing.

Step 2

Clean the floor and the underside of the tub thoroughly around the area where you need to spray the foam insulation. Rubbing alcohol or a common household cleaner can be used, so long as the area is completely dry before you spray the foam. Water or moisture will keep the foam from bonding to the side of the tub and the floor.

Step 3

Read the directions on the can of spray foam to determine the best method for applying the foam, as it varies by manufacturer. Put on safety gear, and shake the can according to the directions and then spray it into the area that needs reinforcing between the tub base and the floor. Do not spray too much because the foam expands over time. Follow the directions for best results.

Things You Will Need

  • Safety glasses
  • Work gloves
  • Dust mask
  • Rubbing alcohol or household cleaner
  • Spray foam


  • Understand that foam insulation is only a temporary fix for your squeaking problem. Foam will compress over time with the weight of water and bodies in and out of the tub, which means eventually it will compress to the point where it no longer supports the tub and you will need to reapply the foam later on down the road. This usually takes several years to occur, but it is an eventuality when you use foam. The same rules apply to acrylic tubs or shower pans; this is why manufacturers recommend setting the tubs in mortar.


  • Wear safety gear when using chemicals.

About the Author

Tim Anderson has been freelance writing since 2007. His has been published online through GTV Magazine, Home Anatomy, TravBuddy, MMO Hub, Killer Guides and the Delegate2 group. He spent more than 15 years as a third-generation tile and stone contractor before transitioning into freelance writing.