Insulating paint, also called ceramic insulation paint, is said to add insulation to the exterior walls of a house. You just paint it on! But does it work? How much insulation does it really add?

Those are the questions at our adobe house as we contemplate the aged stucco exterior which definitely needs improvement. My husband Kelly brought up the idea of insulating paint, so I volunteered to do some research. Our house is a 1940s house, a fairly typical New Mexico adobe home, which we bought half a year ago.

People often think that an adobe house would be warm in winter and cool in summer. That’s true to a degree. Adobe provides thermal mass and we’d like to make the house better insulated. Those are different things.

Insulating paint can be bought ready to use or created by combining an insulating paint additive with the paint you are going to use. There are several brands of additive and of paint.

Insulating Paint Reviews

I do love digging into the research for these articles. As a former librarian, I’ve got a nose for it. This turned out to be a controversial topic.

The Scientific American has a short article summarizing pros and cons. It appears that the paint works by reflecting sun off the roof or wall, so it only helps when the sun is shining on that part of a building. It seems to become less effective with time.

I found a scathing review of insulating paint, with the title Insulating Paint Merchants Dupe Gullible Homeowners. The writer, who has scientific credentials, says near the end of the article, “Guess what — paint is a lousy insulator. ” When I read the page, there were 75 comments, many of them lengthy discussions. The article was written in 2009 and the comments go on for several years. Worth wading through.

Here is a case study by the same writer. A man who was a distributor for an insulating product had his new house in Massachusetts  built with no regular insulation at all, just insulating paint, and it did not turn out at all well.

Here’s another undated pro-and-con article that ultimately ends up quite dubious about the products.

Totally in favor of these coatings is this article on television home building expert Bob Vila’s site. I did note that it quotes the developer of one of the coatings as an authority, and also that it wasn’t written by Vilas himself.

Washington State University has a 2007 PDF summarizing research on the Insuladd brand of additive. See pages 5 and 6 in particular, which is their analysis. Here’s a small part of it, from page 6.

The benefit of this product over time on exterior walls in a real environment, while unknown, very likely may be small. Laboratory measurements on freshly painted surfaces in an indoor, protected environment are not adequate to predict how the product will perform over time in a real application and should be considered skeptically.

About the time I had gone through all these, I was getting dubious, but I did notice that they were all older articles. I was glad to find an article written on a British site just a few weeks ago.  Does Insulation Paint Work? is a good overview. Here is a bit from their section on independent studies of these paints:

Independent studies tend to be lacking on product pages for thermal insulation paint. Instead you might find Mrs. Smith saying “What a wonderful product, I’m so warm now”. “Scientific studies show” is also a go-to phrase used by the insulating paint market.

Well, I thought that would be that. By this point, I wasn’t impressed.

But my independent husband came up with a new idea. He bought a container of Insuladd and some cement pavers and he ran some tests. He wrote a long and detailed article about his tests here. And that’s that. No insulating paint for us, not after his tests. It just didn’t make a difference but ordinary insulation did.