Choosing the proper material for your home’s insulation may have a lasting impact on your comfort and heating/cooling bills. There are two commonly used materials, fiberglass and cellulose. Of the two, fiberglass is more commonly used, but cellulose has been gaining popularity in recent years as people aim to lower their energy bills. Both materials improve the energy efficiency of your home in different ways. In this article, we outline those differences so that you can make a more informed decision based off your homes needs.
CELLULOSE FIBERGLASS
🖒 PROS 🖒 PROS
+ Can be loose or dense as needed + Different insulation styles available
+ Environmentally friendly + Non-flammable
+ Does not degrade + Does not promote mildew/mold growth
+ Does not lose R-value in extreme cold
+ No health concerns 🖓 CONS
- May lose R-value in extreme cold
🖓 CONS - May lose R-value if compressed
- May be flammable - Not moisture-resistant
- Not moisture-resistant - Not an air barrier
- Not an air barrier
- One installation style
R-Value​
When discussing the type of insulation needed for your home, you will notice R-Value is mentioned. R-values determines how insulation performs at blocking thermal transfer. The higher the R-value, the better the insulation performance will be.
Fiberglass and cellulose have similar R-values, with ranges depending on how and where they are installed. When installed properly in similar areas, they perform about the same but may be impacted by outside temperatures depending on the region your home is located in.
According to research done at the Oak Ridge National Lab, fiberglass loses up to 50% of its R-value in very cold conditions; making cellulose a better choice for homes in northern climates. In the summer, according to research by the Brookhaven National Lab, fiberglass loses 3 times more R-value than cellulose when attics reach 110 degrees (F) – very common in most areas of the country.
Air Leakage
Air leakage through cracks and gaps in homes insulation is responsible for approximately one-third of an average home’s heat loss. Neither type of insulation acts as a barrier against air and both types of insulation are ineffective at completely blocking air flow across the attic floor, but cellulose does offers a better overall coverage with its ability to insulate small tight areas, leading to less air flow. When it comes to air leaks, NOTORIA takes pride in never skipping the very important step of Air Gap Sealing, something that is often over looked. All cracks and gaps are sealed off with spray foam prior to installing new insulation, adding an additional reduction of air flow to the attic by tackling something insulation alone can not cover.
Installation​
Fiberglass insulation comes in two forms, batts and blown-in. Although some may want to take the project of installing fiberglass batts themselves, there is a lot of error seen since the insulation must be cut around outlets, wires, and pipes to ensure no gaps are lefts, which may reduce the effectiveness of the insulation. This is one of the reasons why we recommend specialists for what some may see as a DIY project.
Fiberglass blown-in and cellulose insulation is always blown-in using a machine.
Health Issues
In 1994, fiberglass was classified as a potential carcinogen, a cancer-causing material. However, it was declared not to be a health risk to homeowners who have it in their homes.
This is because the small glass fibers that make up the insulation may become airborne if they are disturbed, typically during installation. While they are airborne, they may be inhaled, which over time may cause some types of lung cancer.
Proper installation using masks can protect the installer. Once the material is installed and sealed inside walls, it poses no harm to the occupants of the home.
Cellulose insulation, being made of paper, does not pose any health issues to the installer or home occupants.
Durability​
Cellulose is treated in a way to help prevent rot, decay, and mildew but may still develop these issues if there is prolonged contact with moisture caused by any leaks in the attic. Fiberglass does not rot, decay, or promote mildew growth, but it may lose some of its R-value over time if it becomes compressed. Excessive moisture may cause it to compress and lose some of its air pockets, which in turn makes it less effective over time. NOTORIA does a full attic inspection prior to installing new insulation to make sure there are no leaks to ensure longevity for the new insulation.