What R-Value Do I Need in My Home?

Let R-Values Guide You as You Choose Residential Insulation

Considering how cold the winters are in Wisconsin, it is crucial to have the proper amount of insulation in your home. This can be represented by the insulation’s R-value, and higher is typically better. The ideal R-value will vary by the area of the home you are insulating and your geographical region.

What Does R-Value Mean?

The R-value of insulation refers to its resistance to the conduction of heat. Higher R-values mean the insulation resists the flow of heat better and it will be a more effective insulating material. The R-value of insulation will vary by the type of material, and the total R-value you need depends on what part of your home you are insulating.

Here are the typical R-values for the most common insulation products:

• Fiberglass batts: Made from glass fibers formed into a blanket or batt, fiberglass batts offer good thermal performance with an R-value ranging from R-3.8 to R-4.3 per inch of installed material.
• Blown-in fiberglass: Installed in attics or small openings in a finished wall, blown-in fiberglass offers R-values from R-2.3 to R-3.8 per inch and is ideal for existing homes that need more insulation.
• Cellulose: Another blown-in insulation, cellulose is made mostly from recycled newspaper treated to resist fire and pests. It offers R-values from R-3.1 to R-3.8 of installed thickness, and because it fills the wall cavity completely, it provides good air sealing, as well.
• Mineral wool: Available in batts, mineral wool insulation (often called Rockwool) is made from spun rock fibers that are naturally resistant to fire, mold and pests. It offers R-values of R-3.3 to R-4.2 per inch of thickness and performs similar to fiberglass.
• Spray foam: A liquid that expands and hardens after it is sprayed, spray foam offers excellent insulation and air sealing in one product, and the closed-cell variety is also water-resistant. With R-values ranging from R-4.6 to R-6.5 per inch, it is ideal for fitting high amounts of insulation in a limited space.
• Rigid foam: Extruded or expanded foam that is formed into sheets, rigid foam offers excellent thermal performance with R-values ranging from R-3.6 to R-8.0 per inch depending on type and installation method.

What R-Value Do I Need?

All but the most northern parts of Wisconsin are classified as climate zone 6, including Milwaukee, Madison, Waukesha and nearby areas. This means that according to the U.S. Department of Energy, for the best performance, homes in this region will need the following amounts of insulation in each area:

• R-49 to R-60 in the attic
• R-13 to R-15 in 2×4 exterior walls
• R-19 to R-21 in 2×6 exterior walls
• R-25 to R-30 in floors and crawl spaces

Northern Wisconsin is in climate zone 7 and requires similar amounts of insulation as zone 6. Northern Illinois is in climate zone 5 and will require a minimum of R-38 and up to R-60 in the attic, but otherwise, the values are similar to zone 6.

It is rarely worth the extra investment to go above these recommendations. If you are unsure of the R-value of your current insulation, measure its thickness and multiply it by the R-value per inch for the appropriate material.

Insulation Services in Wisconsin and Northern Illinois

Do you need more insulation for your Wisconsin or Illinois home? Talk to our experts at Alpine Insulation to find out. We serve homeowners in southern and central Wisconsin, as well as northern Illinois.

We install all common residential and commercial insulation types, including spray foam, fiberglass, cellulose, Rockwool, and more. With over 40 years of experience and a reputation for quality, you can expect professional, energy-efficient results.

Call us today at (866) 261-1090 or contact us online to request a quote for insulation services in Wisconsin or northern Illinois!