Need Help with IR images

I had the opportunity to use my IR camera on a home today. It was a rent to own with no agent and I had done an inspection for this couple about 4 years ago.

The weather was overcast and 25 degrees with partial snow cover. House was built in 2000 and is a 2 story colonial faces south.

I took about 85 images and used none for inspection report but wanted to get the feel of using in the field.

The insulation in the attic and walls was not so good!! You can see the thermal bridging on the great room ceiling.

The first picture and illustration is of the great room ceiling. I noted heat entering the attic as I placed my hand in the insulation. There was no visible light or flex ducts.

I did note the uneven snow melt and open areas to the attic adjacent the masonry fireplace chimney. (north exposure)

I would love some of your guys years or knowledge on the images.

I have many imaged I would like to go over but this was one that had me confused. The blue spot off the chimney and outside wall.

How do you reach the high ceilings to confirm with a moisture meter. (extension pole?)

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Thermal images appear to have been made with the auto span and range. It appears that on the exterior view of home there may be thermal anomalies that would be visible if the image was tuned for the structure. On the exterior view of home I do not see the “blue” spot you are talking about. Interior view of ceiling shows small areas of gaps in insulation with some bridging. Interior view of attic appears slightly out of focus. It also shows small gaps in insulation. What is the thickness of the insulation? What was interior temperature?

70 degrees interior temp and insulation was R30.

The exterior photo shows that the snow has melted around the base of the chimney on both sides. Was the fireplace in use at the time of the photo? I suspect what the IR image indicated was a cooler area, maybe from the moisture from the melted snow.

Just a guess


The exterior photo shows that the snow has melted around the base of the chimney on both sides. Was the fireplace in use at the time of the photo? I suspect what the IR image indicated was a cooler area, maybe from the moisture from the melted snow.

Just a guess. I never did IR


Fireplace was off and occupant did not know how to light the gas logs.

I have a feeling that interior air is leaking out around exterior portion of chimney or chimney is drafting warm air from inside home. (As long as fireplace had not been used.) There is a warmer area visible around entire chimney. Since the house faces North and it is overcast, thermal loading of bricks from the sun did not happen so first thought is the area of warmth around chimney is from interior of home.

Stack effect and thermal bridging.
You can see the wall studs in the thermograms on the rear envelope.
Likely no insulation.

Sorry for the narrative edit.

Thank you for the informative posts. Here is another one of the fireplace after I had just turned on the gas logs to demonstrate how the fireplace operated. It was not being used as I stated previously. Looks like some air leakage above the fireplace as well.

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If there was no insulation, the thermal patterns would be the reverse of what we see in these images (i.e., the studs and joists would be warmer than the spaces between when viewed from the interior and cooler when viewed from the unconditioned side).

Much thanks.
I will review the thermal pattern.

You view on stack effect?

I may be mistaken but to me they appear warmer.

Am I mistaken?

Morning, David.
What Flir camera model you using. Just curious.
Appears to take good quality thermograms.

Stack effect and thermal bridging occur in most all structures to varying degrees. You could say it about any house under the right conditions. Not sure what you’re looking for.

What I see is pretty typical for air leakage at the top plate and fireplace and the small triangular anomalies are common for batt insulation where the corners have not been pressed down fully to make contact with the air barrier (sheetrock in this instance).

I really don’t see anything exceptional for the period of construction in the images that we have to work with. I’ve never seen a house with a perfect thermal envelope.

Yes they do when you observe them from the unconditioned / cooler side (though the image needs to be better tuned), which supports my assertion that the wall IS insulated. The wood framing has less resistance to thermal transfer than the insulation, so more heat is conducted from the interior to the exterior through the studs than through the insulated space between. If the wall was not insulated the studs would appear cooler, because they would have greater resistance to thermal transfer than the empty cavity between them.

An uninsulated wall assembly, without material or manufactured insulation, has an R value of up to ><R12, considering the outer veneer is brick, so I have read.
Should, Would, Could that be considered as insulated/insulation? If so what would the correct verbiage be?

No. And it wouldn’t change the relationship between the studs and the space between - they both have the same materials covering on both the inward and outward facing side.We are taking about insulation between the framing members (at least I am - you said it had no insulation).

Where’s the brick? I see clapboard.

David, Everything that you are showing here is “normal” to almost every house in that neighborhood, built under these specifications, viewed under these weather conditions.

Heat around a chimney is because there is a gap left at the connection to the building. Air in the attic is always warmer than outdoors (winter and summer). This space is supposed to be there.

Areas around fireplace walls always have gaps. What it costs to access these areas is greater than the cost of 10 yrs of efficiency losses. I have them in my house and didn’t fix them till I remodeled the fireplace years later.

Fiberglass batt insulation always leaks when not properly installed (eventually you will see what everyone has been missing all these years before IR).

There is always air leaks above the exterior wall headers because there is supposed to be ventilation there (plus insulation in the shared space).

You are going to have to learn to “see” again! :slight_smile:

This is what has been talked about in the past: “You must know what your pointing the camera at to utilize IR on it.”. In time you will learn more than you ever knew before.

When I went to Level II in Boston, I stopped by a commercial building I had insulated as a kid 30 years earlier and asked the owner if I could scan it. I built it (not knowing what I now know) and wanted to see how what I did worked.

When I went to Building Science in Boston, I sat down with Scott Wood at lunch and did the same thing your doing here on a house I inspected that was in a law suit (which I used IR on before I had any training). I luckily was spot on. I had not committed my thermal findings until I completed my training…

Keep it up. IR is not point and shoot. Also Thermal Inspections go way further than most HI’s Inspection Standard. You don’t just see something and call it out (after coming here getting an onslaught of guesses). You must further investigate (especially now at your current level) what is causing the anomaly your looking at. Determine if what your looking at is in fact a “Significant Deficiency” to be reported.

There is an air gap around the chimney.
There are spaces at all fiberglass insulation splices.
Wall fiberglass that is not secured to the Sheetrock gets an air gap that causes convection losses and renders that insulation batt useless, even though it is in fact there.

Also, do not depend on the moisture meter. It lies. Even when there is measurable moisture, it my not be anything more than an air leak condensing.

Upload your scans to Drop Box or something. I talk with you about stuff over the phone. Your a good conscientious Inspector and your going to make a good Thermographer. I’d be happy to help.

very nice David

Great constructive commend David.