Attic Insulation Done Wrong... and How to Do It Right!

In Episode 71 of the On the Job Video series, Larry Janesky, owner and founder of Dr. Energy Saver, walks us through the attic of a home in Connecticut that had been previously insulated by another contractor to illustrate common mistakes being perpetrated by many insulation contractors across the country.

The owners of this home had serious comfort issues, with uneven temperatures around the house and rooms that were just drafty and hard to heat. They called contractors from the state energy program for help. After a quick energy audit, the contractors informed the homeowners that they would benefit from additional attic insulation -- and the contractor was then hired to add inches of blown fiberglass to the attic.

After the work was performed, however, the home was still just as uncomfortable as it was before. That is when they decided to call in Dr. Energy Saver and find out what went wrong. After performing a blower door test, Larry and his team realized that there was a significant amount of air leaking in and out of the house, greatly impacting comfort and energy savings.

Sure enough, when Dr. Energy Saver’s technicians inspected the recently insulated attic they found out that no air sealing was performed in the area. The only way to stop cold air from leaking into a house and making it uncomfortable is to stop heated air from leaking out – and since heated air rises, it usually leaks out of the upper levels of the house. The smallest gaps in the building, such as those around pipes and wires, lights, bathroom fans, duct chases and other ceiling fixtures, can amount to huge leakages.
Blown fiberglass does nothing to stop air leakages. The air flows right through it.

It is, therefore, very important to thoroughly air seal the attic completely before applying insulation. In this case, Dr. Energy Saver had to vacuum all the fiberglass insulation out of the attic just to be able to access the areas that needed to be sealed. After air sealing the attic, a new blower door test showed that they were able to reduce overall air leakage by 20%. After that, new plywood dams were built to contain the new cellulose insulation, which has a higher R-Value per inch than fiberglass. This brought the R-Value of the attic insulation up to U.S. Department of Energy’s recommended levels for the Northeast.

According to Larry, installing attic insulation without air sealing is malpractice, yet it is a very common practice among contractors because homeowners aren’t always aware of the problem. We hope this video will help homeowners across the U.S. make informed decisions when it comes to improving comfort and energy efficiency in their homes.