 Steve Leinweber, Springs Utilities conservation specialist
Feb. 15, 2008
Insulation and R-Value
Have you ever wondered how much insulation you actually have in your ceiling, walls and floor? What r-values do you have compared to what is recommended? What will it take for you to get to the recommended amount? Well, with the easy steps below, I'll help you figure out what you have and show you how to calculate it. Step 1) What kind of insulation do I have? - Fiberglass
- Rock Wool or Mineral Wool
- Cellulose
- Polyurethane Foam
- Polystyrene Foam
- Vermiculite
- Perlite
Step 2) What type of insulation do I have? - Blown-in
- Blankets or batts
- Rigid foam board
Step 3) How much insulation do I have? In the Attic - Measure the depth with a ruler. How deep is it? In the wallS - The average home has 3 1/2” of insulation in the walls. Under the floors - If you have a basement, measure the depth with a ruler. If you do not have a basement and you have a crawl space, it will be necessary to access the crawl to measure the insulation. If your home is on a solid foundation you can assume you have no insulation between the concrete and the ground. R-value is the rating per inch of thickness. - Fiberglass Batts - 2.9 to 3.2
- Fiberglass loose fill - 2.9 to 3.2
- Loose fill mineral wool - 3.3
- Cellulose - 3.2
- Polystyrene Board, Extruded - 5.0
- Polystyrene Board, Expanded - 4.0
- Foam - 3.9
Now you can calculate your R-value. | 
