Insulation is one of the most effective ways to improve your home's energy efficiency and comfort. Acting like a shell for your home, insulation helps to keep cool air in and hot air out during the summer months, and vice versa when temperatures drop during the winter. The material works by trapping the air in small pockets within the fiber, decreasing and slowing the flow of heat.
Insulation can be found throughout many different areas of your home, including ceilings, underneath floors, crawl spaces, walls, and around ducts and pipes. Here are some typical insulation materials used in homes today:
- Fiberglass (both in batt and blown-in forms)
- Mineral Wool (less common now, both in batt and loose fill forms)
- Cellulose (made from recycled newsprint, cardboard, and other similar materials)
- Rigid foam board (made from varieties of polystyrene and other similar materials)
- Spray foam (made from mostly polyurethane and polystyrene)
Insulation and its effectiveness
But how effective is your home's insulation? It depends on the type of insulation (see the list above) that is currently installed in your home. The effectiveness can be measured by the insulation's heat resistance, more commonly known as the R-value. Remember: the higher the R-value, the more effective of an insulator the material is.
Once you know what type of insulation is installed in your home, you can roughly calculate its R-value by measuring the thickness of the insulation and referencing the chart below:
|Type of Insulation|| R-Value per inch|
| Mineral Wool (batts)||3.5|
| Mineral Wool (loose fill)||2.9|
| Fiberglass (batts)||3.1-3.5|
| Fiberglass (blown-in)||2.9-3.7|
| Polystyrene boards (rigid)||3.6-5.3|
| Polyurethane boards (rigid)||5.6-7.7|
|Spray foam (high density)||6.0-7.0|
| Spray foam (low density)||3.0-3.5|
If you are unsure about the type of insulation in your home, an Inspections Unlimited inspector can easily assist you in identifying and evaluating your insulation. An inspection can also help you determine if the amount of insulation in your home is sufficient.
Remember, the amount of insulation needed to adequately do its job depends on what area of the house you are looking at, along with the climate and region of the home itself. Here in the Pacific Northwest, building codes recommend specific amounts of insulation to best defend against the climate, weather, and season changes. See the chart below for the specific recommendations:
| Crawl space, under floor||R-19|
| Crawl space, perimeter exterior||R-10|
| Crawl space, perimeter interior||R-19|
|Piping||R-3 or more|
For other geographical regions and areas, the U.S. department of Energy offers an online estimate tool that can calculate insulation recommendations based on your Zip Code. Visit the DOE website to learn more about insulation needs based on your specific location.
How a home inspection can help
An adequately insulated house can make for a comfortable, energy efficient home. It is important to check the condition of your home's current insulation for correct quantities and completeness. Homeowners are often surprised at the common problems that can plague their home's insulation. During construction or home improvement projects, insulation can be moved or thrown aside to allow easier access for workers - but it isn't always put back. Insulation can also be damaged during the installation of cables, wiring, and plumbing.
Other issues that can occur include attic insulation that has been packed down from walking on it (this depletes its efficiency), water damage, and damage caused by animals and other pests. For houses built before 1980, Inspections Unlimited recommends homeowners upgrade their insulation to ensure efficiency and quality. Homeowners with newer houses should also consider double-checking the current state of their home's insulation.
During a home inspection, an Inspections Unlimited professional can identify damages and problems, along with the specifics of your home's insulation type and quantity. Homeowners can refer to their Inspections Report and use it as a tool when planning repairs. Are you still unsure about the material or condition of the insulation in your home? Schedule an evaluation with us today.