How to Insulate Your Attic with Blown in Insulation
One of the biggest contributors to heat loss and heat gain is the ceiling of your house. Hot air that is heating your house rises to the ceiling and goes through the ceiling into the attic and out through the roof of your house. Likewise, hot air from the attic enters your house through the ceiling in the summer time when the air conditioning unit is on.
Most homes built more than ten years ago have insufficient attic insulation. Current codes are higher than they have ever been and are constantly increasing as more and more studies are conducted in regards to the amount of insulation that an ideal home should have in it.
The insulating factor of any product that is used to insulate your home is assigned an R value or R factor. This number is used to determine how much of a given insulation is needed for your home depending upon the location of the house in this country. Northern homes typically require more insulation than southern homes due to the harsh winter in the north. The chart can be referenced to determine how much insulation your house requires. Different areas of your home need different levels of insulation. The list below shows the recommended attic R-value for homes in the Midwest.
Attic: R-38 to R-44
Attic R values throughout the nation should also be in or near this range
If you heat your home with electricity, proper attic insulation is even more crucial, because electric heat is costlier and less energy-efficient. The U.S. Department of Energy recommends R-49 attic insulation for homes with electrical resistance (baseboard) heating.
Now that you have determined how much insulation your attic needs, you must first determine how much insulation is already in your attic. To do this, you will have to enter the attic, determine the type of material in the attic, and measure its depth. The materials will be either fiberglass bats, (the pink stuff usually) or blown in insulation (you can pick up a little of this easily to determine if it is blown in as it is not attached to anything).
Most insulation has an R value of between 3 and 4 per inch. So you need to convert the inches that you measured, to an R value. For example, if you measure 4 inches of insulation and times it by 3, you end up with an R value of 12.
Now refer back to the chart listed above and take the R value that your house requires and minus the R value that is currently in your home. Jot down the approximate square dimension of your attic in length and width and head up to your local home center with this information. They will be able to determine the amount of blown in insulation need for your job.
Once you have purchased your blown in insulation, you will need to rent the machine that blows the insulation into your attic. Most home centers will rent this to you for free if you purchase a listed amount or more of the insulation from their store. Be certain that you have asked for enough tubing with this machine to reach from the ground outside of your home where the machine will sit to the farthest part away from this position in your attic.
Now you can begin blowing in the insulation. It is a two person job and I would suggest that the person who is positioned in the attic wears gloves, a hat, a dust mask, and a breathing barrier or face mask approved for dust particles. The person in the attic should also have a yardstick and a flashlight.
To begin you will need to run the tubing from the machine up through the access point of your attic. If there are any joints in the tubing, duct tape them together to avoid any insulation blowing out into your house. Once the tubing has reached the farthest point away from your access hole to the attic, you are ready to begin blowing the insulation in. You will need to tell your partner who is operating the machine to start and to stop throughout the process. A two way radio works well for this.
The machine is started and the insulation begins to fill the attic. You must aim the tube around in your attic to fill in all of the spaces. You should periodically check the height of the insulation to know when to stop filling a certain area. Continue moving throughout your attic. You want to move towards the access point as the attic fills up to the desired height. Once you have reached the desired height of fill throughout the attic, you are done. If there is left over insulation, you can simply spread some more throughout the attic or keep it for a later time.
Just remember to cover the access hole, and clean the area around the access hole as there will likely be debris spread around in that room. Return the machine to your home center and enjoy your lower heating and cooling bills.
