Staying Warm and Cosey
Common Insulation Options for your Home
The goal of adding insulation to your attic space is to trap heat and keep it from exiting your home, thus keeping the home more comfortable and saving on energy bills. Insulation material’s effectiveness in achieving that goal is referred to as its R-Value.
The R-Value of insulation that your attic should maintain depends on where you live and what the climate is like. Hot climates call for an R30 value, cold climates command an R49 value, and moderate climates fall in between.
Calculate R-value by dividing the recommended R-value for your area by the R-value of your particular type of insulation, you can find what an attic should have on average:
Here are the R-values per inch of the most common types of insulation:
· Fiberglass (loose): 2.2 – 2.9
· Fiberglass (batts): 2.9 – 3.8
· Cellulose (loose): 3.1 – 3.8
· Rock Wool (loose): 2.2 – 3.3
· Foam (sprayed): 3.6 – 8.2
Common Types of Insulation
Fiberglass Loose
Fiberglass is extremely delicate glass fibers that are comprised of recycled material and sand and looks like cotton candy.
Advantages of Loose Fiberglass Insulation
Moisture Resistance – Though fiberglass isn’t impervious to water, it does tend to resist moisture effectively. This makes it less vulnerable to the growth of mold and mildew.
Fire Resistance – Fiberglass is noncombustible, however, the paper that holds the batt together may not be, so it is important to follow manufacturer specifications for installation.
Easy Installation – It is blown in and is best suited for additional coverage or tight spot.
Cost-effective – One of the cheaper options for insulation.
Fiberglass Batt Insulation
Fiberglass is extremely delicate glass fibers that are comprised of recycled material and sand. The most common form that fiberglass insulation takes is in batts, large rolled-up sheets that are held together by an adhesive vapor barrier like reflective foil backing or paper.
Advantages of Fiberglass Batt Insulation
Moisture Resistance – Though fiberglass isn’t impervious to water, it does tend to resist moisture effectively. This makes it less vulnerable to the growth of mold and mildew.
Fire Resistance – Fiberglass is noncombustible, however, the paper that holds the batt together may not be, so it is important to follow manufacturer specifications for installation.
Easy Installation – Batts are easy to pick up and unfurl. And due to their size, they can cover a lot of real estate in a pinch. This makes them a prime candidate for new construction as long as they are installed properly.
Cellulose
Cellulose is made from pieces of newspaper that are shredded into extremely fine pieces.
Advantages of Cellulose Insulation
More Cost-Effective – Despite having a higher R-Value than most fiberglass, cellulose tends to be considerably cheaper. Generally speaking, blown-in cellulose will cost you up to 1/4th less than blown-in fiberglass. Even though cellulose is a very cost-effective option, it’s cheap for a reason.
Not as moisture-resistant as other insulation products.
Rock/Mineral Wool
Rock wool or mineral wool is composed primarily of basalt rock and a recycled steel-making byproduct known as slag. These components are superheated, allowing them to liquefy and mix into a lava-like liquid. To melt these substances, the temperatures must exceed 2,900 degrees Fahrenheit.
The mixture is then blown into a large spinning chamber designed to stretch the superheated liquid into fibers. These fibers are then gathered together and compressed into a mat, which can be cut into slabs of rock/mineral wool insulation.
Advantages of Rock Wool Insulation
The process of creating this material greatly increases the mold and mildew-resistance of the finished product.
The material is fire-resistant up to 1,400 degrees Fahrenheit.
Written by: Joe Gardino, Senior Professional Home Inspector
