Bad insulation job caught by an infrared inspection

I am a Home Inspector and Energy Auditor here in Chicago and my clients are always asking me why their homes are so drafty and their heat bills astronomical. The most common problem causing major comfort issues is air infiltration into the home.

A client wanted to know why the floor was so cold under his desk in the bedroom above the Foyer. He recently paid to have the entire home insulated with blown in cellulose, so naturally assumed that all the walls were filled right? WRONG!

During a blower door test/infrared inspection, my infrared camera revealed the answer in a few seconds. Although the home was supposedly “100% insulated” the contractor apparently missed the entire wall cavity to the left of the window in the Foyer, thereby causing cold air to infiltrate up the wall and across the ceiling joist bay causing the floor to be cold in this area. There were several other areas in the house that were missed or not filled 100%.

This is a good example of the benefit of having a Blower Door test/Infrared Camera inspection, especially before and after insulating. Firstly to locate the source of the air leaks to determine the best course of action and material to insulate with, and secondly to make sure the job was done correctly.

My infrared photo revealed the missing insulation to the left of the window and shows the path of cold air infiltration up the wall and then all along the ceiling (floor upstairs) explaining the cold floor above.

Here is another example of missing/settled insulation. I found areas like this all over the home

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Insulation (or lack thereof) has nothing to do with “draft”.

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Sure it does. By using foam instead of cellulose you can cut air infiltration

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Your photos of missing insulation have nothing at all to do with the draft that your client is complaining about, David.

What was the CFM at -50 pa and the cubic feet of conditioned space?

My client has since had that missing stud bay filled with foam and the air infiltration has stopped traveling up the wall and along the floor joist bay.

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I think what James is saying is that insulation is not an air barrier. However, foam sprayed into the cavity can be considered both an air barrier and insulation.

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I see no pattern for air infiltration in the photos, though. I’d still like to know the results of the blower door test.

That looks more like convection from poorly installed insulation. Missing insulation looks more like this:

Out of curiosity, where did you get your thermal imaging training?

Linas, I think you have a far superior IR Camera than David and that you are both correct.

Here are some better images of air migration. You can see the movement.

I got one of missing insulation…:stuck_out_tongue:

and one of a crappy install…:smiley:

I did this house on Saturday night at 2am(partial inspection because they were always cold upstairs). Oddest inspection request time I’ve ever had!

There was literally a 20 degree difference between the upstairs and downstairs. I was sweating downstairs and freezing upstairs.

They just installed a brand-new furnace in the attic to try and keep the upstairs warm vs. realizing a bit of upstairs insulation would have worked wonders.








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These are awesome pics.

And this is why I work with a blower door test contractor: he finds the air leaks first before insulation goes in.

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