One VERY IMPORTANT thing I do on a one-year warranty inspection is sweep the house with my thermal camera to see if there is slipping insulation.
It is important to do this because the camera can definitively determine if the insulation has actually slipped. Done before the warranty is expired puts the fix back in the builder's lap.
But be careful. Some "one-year" warranties expire in 11 months! That's a another little trick employed in recent times. So check your contract carefully before you hire a home inspector.

These are two different views of the same room. It is the fourth level of a single-family house.
I love four levels in a house. It makes for a very fun, versatile room and there is little wasted attic space.
In this case the ceiling is peaked. The drywall you see is not very far from the roof.
These images are taken in the morning. This room faces east and west.
The image on the left is the west side. Part of this vertical wall is exposed in the attic space. As such the entirety of that wall should be insulated.
From the attic it was evident that the insulation had come loose and some had fallen down. That purple spot is an area where the builder dug through the insulation to get at something down the wall, and never replaced it. That is the coldest spot in the image, and 42F. By contrast, look how warm the rest of the wall looks!
And look at how the camera organizes the 307,200 pixel points of temperature in each of these two images. The walls look warm (orange and yellow) in the left image and cool (lavender and blue) in the right image because the camera is demonstrating contrast. The temperatures in the walls and ceiling are not that much different between these two images, but appear so because of the temperature contrast.
The image on the right is the east side of the same room! Look how the sun on that side of the house is heating the attic space there. And again, look at how poorly placed the insulation is, literally coming off the wall!
Why does insulation slip? Insulation has flaps on the paper of the vapor retarder stuck to one side. Those flaps are there for a reason! AND THAT REASON IS TO STAPLE IT TO THE STUDS!
When it isn't stapled, over time, it will sink. Why? BECAUSE GRAVITY WORKS! Staples are how I determine the quality of the insulation job on a pre-drywall inspection. I do that so that the one-year inspection doesn't reveal what this one has.
I have seen very high cathedral-ceiling walls where the insulation has slipped down about one third in the first year. That is a difficult problem to fix because it requires removing and replacing drywall. In this case it isn't so hard to go into the attic to staple this stuff up properly. BUT IT MUST BE DONE! And the time to catch it is during the warranty period!!
These people have complained that this room was inordinately hot and cold. Well no wonder!
My recommendation: get a one-year inspection on your home! And if possible, hire a thermographer to try to catch poorly insulated areas. You will be far more comfortable if you do. Peace of mind is worth a million bucks! It's certainly worth the price of a thermal image inspection. And remember the other benefit - thermographers are all really cute.
Jay Markanich Real Estate Inspections, LLC 
Based in Bristow, serving all of Northern Virginia
www.jaymarinspect.com



39 Comments on Slipping Insulation
Jay, it is hard for me to have a meaningful conversation about fiberglass insulation. It is so far from being effective as insulation for so many reasons. Cold air and hot air can flow behind batt type insulation whether in place or out of place. Seeing it falling out of place on the attic side of vaulted ceiling areas is very common as well.
Jay - Don't know how many times I've seen insulation contractors install insulation with too few or no staples, expecting friction to hold the batts in place--great justification for having a pre-drywall inspection.
Ann - improperly installed insulation is a big deal because it stays with the house for a long time!
Michael - a thermal camera is the best way to see insulation issues, summer and winter.
Jim - in this case it was just crappy installation. That room did not take the entirety of the attic space and there was visible access behind each side of the room. It was just coming off or had fallen down. Then that one spot someone had dug into it to run something. Maybe the satellite guy!
Batts everywhere Reubs. Sometimes there is the blown-in stuff on the flat surfaces, but never blown-in on an angled ceiling.
That's hard on insulation long term, Mike, especially on outside walls because it can get heavy with condensation. Stapling works.
That's true Marc. And I usually suggest they wait a year to see if there is a problem because that puts them within the warranty period.
Joy - my understanding is that even today a small percentage of inspectors use it. Maybe that's because one of the requirements is that the one who do use it have to be cute too.
Barbara-Jo - and the two year warranty is done at twenty two months! I think it's a trick myself.
Debbie - not sure I understand, but it started a couple of years ago.
Cellulose can compact more than fiberglass Clint, and I didn't know traffic can cause it to slip. I guess from the vibration.
Richie - the older I get the less X-ray I have. So I rely on my camera!
I do too Chris. I recognized the benefits really early on (actually the first time my son was in Iraq and he had one, telling me about everything they can do) and I looked into it immediately.
I agree Charlie, but it is what it is and it is what they use, at least around here. So it has to be dealt with. That's why I am so careful on a one year.
John - friction can only work so long. I have heard builders tell clients that they use "oversized" insulation, so it holds better. Oversized?
Jay, there is a big advantage to being able to see behind the drywall. Your thermographic camers is a pretty good tool to have.
I think it's the sharpest arrow in my quiver Michael.
Love the thermal imaging device! I want Santa to bring me one! How much do they cost?
I know I took down some walls in a rental home and was surprised to see how much the siding had slipped down in the wall! I question if it had even been properly affixed at all!
Heather - mine was $15K when I bought it 8 or 9 years ago. I think decent ones are down around $7 or 8K now. But I haven't priced them.
Rosalie - probably not. But time works wonders on everything! We all slip downward with time! ;>)
Jay, most fiberglass batt insulation that is to be encapsulated in side walls is "friction fit" type around here---no stapling involved.
Jay - Never knew about that 12 months warranties. See I learn something everyday in here. Excellent
I hear that too from time to time Charlie. But in the winter, when a dewpoint develops and the insulation gets heavy, even with friction it slips.
R&L - that is something I have seen more and more of in the last couple of years.
It is the cute part that sold me. I am looking for a thermographer.....but wait! Do those work in an ambient temp over 110 degrees?
Jay:
That thermal camera is so cool. Do all inspectors have thermal cameras? I no know very little about insulation, but now I know that the flaps are for stapling the insulation in place. Thanks for the info.
Hi Jay--I learn so many great things every day here in the Rain. The thermal camera is a whole new thing to me (which I like); the 11-month warranty is also new (and I certainly don't like that)!
Yes Marge. Best to use an umbrella so the screen is visible!
Evelyn - a small percentage of home inspectors have thermal cameras. But it is increasing. They are still quite expensive.
Janet - I have used mine for 8 or 9 years now. As to the warranties, some builders have been doing that for a couple of years now.
Jay -- another great lesson. Years ago, we bought a used Triple Wide Manufactured Home. In doing some repair work, found out that they had used plain batt insulation (without any paper on one side). Since it had been moved a couple of times, the insulation was sliding down as well (as I recall about a foot from the top was uninsulated.)
That is huge when temperatures reach extremes Steven, but in the long run that is hugely expensive!
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