What is loose fill insulation?
Loose fill insulation consists of small particles of fiber, foam, or other materials. These small particles form an insulation material that can conform to any space without disturbing structures or finishes. This ability to conform makes loose-fill insulation well suited for retrofits and locations where it would be difficult to install other types of insulation.
The most common types of materials used for loose-fill insulation include cellulose, fiberglass, and mineral (rock or slag) wool. All of these materials are produced using recycled waste materials. Cellulose is primarily made from recycled newsprint. Most fiberglass contains 20% to 30% recycled glass. Mineral wool is usually produced from 75% post-industrial recycled content.
Loose fill insulation can be installed in either enclosed cavities such as walls, or unenclosed spaces such as attics. Because loose fill insulation consists of fluffy strands of fiber blown into attics and walls, a special machine is used. It fills nooks and crannies, which eliminates cold and hot spots.
Different types of loose fill insulation
When insulating your home, you can choose from many types of insulation. To choose the best type of insulation for your home, you should first determine the following:
- Where you want or need to install or add insulation
- The recommended R-values for areas that you want to insulate.
Blown in insulation typically needs to be installed by a professional. Blown in insulation generally creates a more efficient seal and will produce good results after a relatively quick installation period.
Blown in cellulose
Cellulose loose fill insulation uses recyclable materials such as old boxes and newspapers. These materials are reduced and pulverized, making them into the filler of the insulation. After that, chemicals are mixed into the composition to make it resistant to fire and pests.
This fiber is packed tightly into closed building cavities, which inhibits airflow.
The major disadvantage to cellulose is that it absorbs water, which can become a problem if water leaks from the outdoors. Too much water can also wash away the fire retardant.
Advantages: Effective at all temperatures.
Disadvantages: Oftentimes too heavy for attic insulations; ceiling must have at least 5/8 inch drywall or framing every 16 inches. Over time, it can settle almost 20%, reducing its effectiveness.
Best use: ceilings, enclosed existing wall or open new wall cavities, unfinished attic floors, other hard to reach places
Cost: 31 cents per CF
Fiberglass loose fill insulation is created when glass is melted and spun into small fibers. These small fibers serve the same purpose as the pulverized and treated boxes and newspapers in cellulose insulation. Loose fill fiberglass insulation must be applied using an insulation-blowing machine in either open-blow applications (such as attic spaces) or closed-cavity applications (such as those found inside walls or covered attic floors).
Advantages: widely available and familiar, standard widths and thicknesses are designed to fit between studs, joists, and rafters.
Disadvantages: Can be itchy to install. Rolls of fiberglass (which we do not recommend due to the fact that in order for them to be effective, they must be installed perfectly, which is a near impossible task) must be cut by hand to fit into spaces. It compresses easily, which causes it to lose insulating properties over time.
Cost: 30 cents per SF
The term R-Values refers to the measurement of thermal resistance of the insulation. The higher the R-value, the more the insulator is resistant to heat flow. The level of R-value you need for your home is determined by your cooling and heating system, together with the climate in your region.
Each material, and often each brand of the material, has a different R-value. It is also important to remember that the maximum R-value of insulation is very dependent on proper installation.
R-30 insulation in the attic is code, which translates to 10” of cellulose. In Phoenix, R-38 is Energy Star standard and the level that we recommend.
You can find the current R-value of your insulation from the manufacturer’s specifications, or use the BPI R-value table, which is simplified below:
If you think that your home needs an insulation upgrade, make sure that you know the pros and cons to each insulation type in order to make the decision that is best for your home!