The effectiveness of Insulation materials is measured by their thermal resistance, called R-value. For example, on fiberglass bats there will be a rating like R-13. This means the product has a total thermal resistance of 13. For comparison, the same thickness of wood would have an R-value of approximately 4.0. A plain window typically has an R-value between 1 and 2. An R-value of R-0 would indicate no thermal resistance at all, like an open doorway. When the door is open there is nothing resisting the heat from passing through. Every wall in a house has an R-value that is different based on the thickness of the walls and the number of doors and windows that are installed.

Accredited third party testing lab has calculated values of RetroFoam in typical wall construction to range between 14.5 to 23.7 depending on the thickness of the wall and foam.

Many homes with 2X4 studs can have R-values up to 16.0 when RetroFoam is installed

That means better insulation. This saves you money on utility bills.