Energy Hog – Attic Air Sealing

The first of our home improvements projects to cut the energy usage in the home was air sealing in the attic.  Now I have to admit that when I started doing the work in 2005, I did not fully understand the importance.  Now that I inspect homes or follow up on insulation contractors’ work, I see firsthand how important air sealing work really is.

A simple explanation of what air sealing is, it is the work performed on the home to reduce the amount of air infiltration into the home by sealing small and sometimes large gaps and crevices.  I utilized the DO–IT–YOURSELF Guide to Sealing & Insulating with ENERGY STAR to perform the air sealing in the attic before installing insulation.  These holes in the home can waste approximately 25% of the typical homes heating and cooling cost and is almost always the most cost effective improvement that can be done to most homes to reduce the utility bills and increase the indoor air quality (IAQ).

Air sealing not only helps reduce your heating and cooling costs, but sometimes more importantly, air sealing helps to improve the indoor air quality and durability of the home.  Tighter homes typically have less dust because not as much gets pulled in through these cracks; they are typically more durable because excessive air and moisture does not enter the walls or attic that could cause mold and rot.

The goal of air sealing your attic is to make the ceiling as air tight as possible to stop any air movement.  Now most home owners don’t think of their attic being full of holes.  However it is full of them, plumbing stack penetrations, wires, can lights and other ceiling fixtures.  If you hold your hand over these holes, you can feel the hot or cold air from inside your home making its way into the attic, costing you money.  Because as this conditioned air leaves your home, unconditioned air is being pulled into your home through other gaps or crevices in your home, typically in the basement (more on sealing the basement in a future post).  When your home has low levels of insulation, it is easy to find these holes.  However if you have good levels of insulation, you can find these holes by looking for discolored insulation, as most insulation types are air filters and the discoloration is a sign of air movement.  So review the air sealing guide, buy a few tubes of caulk and cans of Great Stuff and seal up those holes and start saving.

Here is a video series on the Fine Homebuilding magazine website on air sealing your attic that is worth watching, or check out other attic air sealing videos on YouTube.

About: Joshua Lloyd (115 Posts)

Joshua has a degree in architecture and is a LEED Accredited Professional that has worked in the design and construction industry for over 10 years, focusing his efforts on energy efficiency and building science. He has organized multiple events in Ohio to give young designers the opportunity to learn about “green” home design and produce actual projects. He was also a key player in Ohio’s first LEED for Homes Platinum project. Joshua is also a certified Building Analyst through the Building Performance Institute and performs home energy audits, assisting home owners in reducing their energy usage.