Foam insulation panels are a convenient and economical way to add insulation to garage doors, sheds, stud walls, foundation walls, attics, roofs, etc. Most of the foam insulation paneling available at home improvement centers is made of either Molded Expanded Polystyrene (MEPS) or Extruded Expanded Polystyrene (XEPS). MEPS will provide an R-value (insulative value) of about four per inch of thickness, and XEPS has an R-value of about five per inch of thickness. Either type of foam insulation paneling you use can be installed using the same installation method.
Cut the foam insulation paneling to size with a utility knife, if needed.
Cut the application end of a tube of adhesive with a utility knife and poke a hole through the inner foil. Load the tube into a caulking gun. Place the plunger firmly against the end of the caulking tube.
Pull the trigger a few times to begin dispensing the glue, and then apply the glue to one side of the foam insulation panels spreading the glue in large s-curves across one whole side of a panel.
Set the caulking gun aside and pick up the foam insulation panel. Put the panel into place with the glued side towards the surface it is being attached to, and apply firm pressure with your hands from the non-glued side of the panel to set the in place. Repeat for each panel that needs to be installed.
Allow the glue to dry for the recommended time before covering the foam insulation paneling with any other type of sheathing (like OSB or drywall).