I have seen a paint advertised as an insulation. Is this for real?
—S.H. Bryson, via e-mail
A: Kevin O'Connor replies:
Sounds like what you're referring to is a type of paint that blocks the transfer of heat through walls. From what I've learned, it wouldn't hurt your house to paint it with this stuff, but it's not likely to reduce your energy bills.
According to Danny Parker, a research scientist at the Florida Solar Energy Center, the R-value of any paint film would be negligible, so using the term "insulation" is a stretch. True, paint can reduce summer heat gain by acting as a radiant barrier and reflecting the sun's rays. But unless there's independent test data about how well it performs, there's no way to compare the benefit of this product to other options, such as insulating walls or installing radiant-barrier foil in the attic.
Even if the paint were a good radiant barrier, its effectiveness would depend on its location: A radiant barrier applied to a shaded wall, for example, won't be much help.
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and see 22 Little Ways to Go Green