Methods for finding uninsulated wall cavities

An insulation contractor told me he goes into a bedroom closet, pokes a little tiny hole in the exterior wall at the bottom corner just inside the door, then sticks a little bent wire in there and rotates it like a pinwheel. That’s how he finds missing insulation.

I’ve been removing cover plates and that usually works, but sometimes you have to cut the drywall back a little and it’s messy. I’ll bet a little wire with the end bent onto a hook would work better at outlets.

I wonder if someone were to hold an electronic guitar tuner next to the wall while tapping the wall, if empty cavities would sound a different note from full cavities. Hey! An excuse to have another electronic gizmo!

IR thermometer worked before I had a camera.

Now I just use the camera.
You can scan a house just about as fast as you can move if you are only looking for insulation absence, voids or air leakage.

With the IR thermometer, during real hot or cold weather I guess it would be obvious. What about when it’s 70 degrees out and indoor and oudoor temperatures might be naturally similar?

I also test Radiant ceiling elements and base board heaters.the same way works well .
Before I had to use a spray water bottle it dried where element was .
Yes they have to be turned on…

… Cookie

I did an inspection for a guy, yesterday. Condo conversion. I had previously done a pre-drywall inspection for him on the property. I told him, and the builder, to make sure to not only install insulation, but also vapor barrier on the outside walls (the unit is a garden apt).

During yesterday’s inspection, I could not see any insulation, at all. (used the B-Cam and checked, with a boroscope, through the receptacle boxes. The contractor kept swearing that he insulated. I told him, “Prove it. Cut out a section of drywall, right here.”

He got all upset, claimed I was calling him a liar and stormed out.

Needless to say, today’s closing was cancelled :mrgreen: .

Client loves me. :wink:

The B-Cam helps and makes thinsg a little easier and faster, but it cannot be a complete substitute for visual inspection.

Hope this helps;

Will -

Great to hear you were able to determine that, just one question from the uneducated (b-cam wise):

I was told you need about 30 degree inside/outside temp differential to ‘see’ insulation with a b-cam, is that correct? Does it vary based on the type of insulation, thickness, etc?

What would your results be at 10 degree difference, or 20, or 5?

The reason I ask is many (most) of my inspections are done when the temp differential is far less then 30 degrees. Of course I could test the heater in the summer for say, two hours and maybe get the house to 110 so I could do an insulation scan :shock::shock::mrgreen::shock:

I’ve detected absent or loose insulation at TD lower than that.

All IR anomaly readings (thermometer or camera) rely on thermal loading of some sort. If everything is the same temp no conclusive results can be ascertained.

Remember we are always looking for differences, inconsistencies or unusual conditions.

Again IR is just another tool, not the do-all, end-all. We’ll have to find other methods when temps are the same throughout.

Here’s one I did, new home selling for 399K

What do those pictures show Peter?

This house had the attic finished into a family room, the first picture shows one complete bay missing insulation from the ridge down to the knee wall, you can see the rafters running vertically and the strapping horizontally.

The second picture shows the A dormer ceiling in the same room and because the roof/ceiling is in such a small or tight area the insulation is just jammed in, should be ( “fluffy not stuffy” )

By the way, my client, after hiring me to add infrared to the inspection did not feel this was a big deal and did not pursue it with the builder and on top of that, the attic/family room has electric heat. OH well!!!

Cool. So there was a 4.5 and 6.5 degree difference in the two photos. The room temp appears to be about 80, what was the outside temp? Weather conditions?

Outside temp. was about 90 in the sun, not sure what the temp. on the roof surface was.

Attic was undoubtedly warmer. Thanks Peter!

Yes, thanks Peter. :wink:

We could always go back in time

we’ll see what I can drum up during today’s insulation “energy” inspection.

What’s included in the energy inspection, Barry?

This one pertained to the home owner’s concerns over increased energy bills.
They are on a fixed rate billing and have noticed an expense increase over time.

They felt their home was not properly insulated and wanted advisements on how thy could retrofit to reduce usage.

Nothing major as far as actual insulation absence or improperly sealed ductwork was identified during a 3 hr. investigation of the major systems.

  1. Properly program thermostats and attempt to increase or decrease seasonally
  2. Balance HVAC systems
  3. Replace filters for HVAC systems
  4. Install outlet insulators
  5. Properly program pool timer (16 hr run time excessive)
  6. Unplug or turn off items no in use
  7. Reduce thermostats at both WH 141-147°F
  8. Properly switch ceiling fan rotation seasonally (read instructions)
  9. Install weatherstripping at all exterior door units and add attic stair/door insulation
  10. Seal plumbing penetrations and escutcheons

Just the basics that have been around for years, but it helps keep food on the table.