Homeowner seals attic 'big offenders,' then infrared images suggest little changed

A homeowner trying to cut attic air leaks expected a clear payoff after sealing some of the space's biggest problem areas. 

Instead, their thermal-camera results looked almost unchanged, raising a question many DIYers eventually ask: Was all that effort actually doing anything?

Here's what to know

The homeowner took to Reddit's r/Insulation community to ask about air sealing. This original poster wrote that they had "been wanting to try some air sealing in my attic [to address] some of the 'big offenders' that I've seen in my house."

OP shared before-and-after infrared images of their attic, writing that they found "it doesn't seem like it was as effective as I expected," and asking the subreddit, "Am I wasting my time?"

The OP said that they had expected at least some improvement, writing, "I assumed anything would be helpful since the electrical box started with open holes to the attic with no insulation around it." Yet after "spending too much time building the box and crawling around attempting to seal it," the infrared comparison still seemed to show only a minor change.

They also cited a bathroom vent that had hit "110°+," another spot where the effectiveness of attic sealing work was hard to judge.

Most replies said the effort was still worthwhile. 

One commenter wrote, "The air seal doesn't necessarily improve temps but what it does is stop the air from freely moving. There is a difference due to how well it keeps that heat from flowing but yes it will still transfer. Windows will always be low R value but how well they prevent drafts makes the larger difference."

Another user added, "Not a waste of time. I've used some of the canned light covers and it makes a big difference."

A third said, "definitely not a waste of time. Having an effective building envelope will make you more comfortable inside and also improve energy consumption. It's not always easy or straightforward air sealing attic boxes."

Advice in the thread centered on making the fix easier, not abandoning it. One commenter suggested treating junction boxes more simply, saying, "Just seal j boxes with a caulk gun and tube of fire caulk. You're making it way too complicated."

Where can I learn more?

For more on how people are dealing with heat, airflow, air quality, and insulation challenges, these stories explore a range of approaches. 

• Researchers found historic buildings perform way better than expected when natural ventilation is done right.

• One contractor showed how to best use an attic fan to keep homes cooler.

• Scientists found air purifiers aren't enough when wildfire smoke and VOCs seep indoors.

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