Is paint an effective radiant barrier in the attic? In short, the answer is no.
I had heard, but had not yet seen, that there is a contractor running around telling people that he can get them "energy savings" if they paint their attic spaces his special silver-colored paint, and it will save zillions of $ in energy.
Well, I finally saw such an attic!
Interior Radiant Control Coatings (IRCC) include radiant foils and the so-called "ceramic" paints. Any such paint must meet standards determined by the American Society of Testing and Materials, which recently changed its name to ASTM International. And they do just that. They set standards for many things.
Any such so-called radiant barrier control paint, "ceramic" paint, or whatever, is supposed to meet an ASTM standard stated in ASTM C1321. The Reflective Insulation Manufacturers Association (RIMA International), has agreed with the definition of that standard, which is a barrier that provides better than 75% thermal reflectivity, and a thermal emittance of 0.25 or less.
Of course, RIMA states that radiant barriers are more effective in warmer climates, and less in mild and cold climates. But that regards the foils, not paints.
RIMA says (click here for the full statement), "One of the major misconceptions in the insulating paint field is that “ceramic paints” can be used on the interior like an IRCC to reduce attic temperatures and lower cooling energy costs. However, the application of a “ceramic paint” to the underside of roof sheathing may increase the attic temperature because “ceramic paints” typically have a higher emittance than the sheathing deck."
Paint is not a "barrier." It is a misconception to call it such. All of the standards people warn about contractors that use inferior paint and claim it meets standards, they water it down
In this attic only about 2/3 of the roof sheathing was so painted. I could see where they painted over mold, so the coating was very thin. And they painted the sheathing over only one half of the house! So this was a complete lie perpetrated onto an unsuspecting, but trusting, homeowner.
Here is the dirty little secret. Not that much radiant heat actually influences the interior of the house. And nobody seems to be able to determine energy savings when such radiant barriers are installed! That is what insulation is for! And in a consumer report states that foil studies show that any insulation that provides R-39 or better will be more effective in the long run than any radiant barrier (foil or paint) that can be added to an attic space.
So, there it is. We are better if we insulate better! Insulation in an existing house can always be added to, and when that is done the insulation value is cumulative.
My recommendation: before you go to the expense of "improving" the energy efficiency of your home, investigate it completely. Research is easy these days. Find out what you can find out. But trusting the claims of contractors who want your money is not the best way to go. It probably never is.
Jay Markanich Real Estate Inspections, LLC 
Based in Bristow, serving all of Northern Virginia.
Office (703) 330-6388 Cell (703) 585-7560
Good morning Jay,
Have never heard of painting the attic for energy savings. Will stick with the insulation and venting.
Make yourself a great day.
You're sticking with tried and true, Raymond? You sure? Isn't that an old and tired voice?
I'm with you!
Jay Markanich It appears this particular 'contractor' might have been a 'Traveler', as we call them . Definitely a scammer!
"A traveler, he," quoth Robin Hood of Will Scarlet.
Perhaps S&N. But I have heard he is "out there," and this is my first encounter with his fine work.
What was it a prophet once said? Oh, "There are two paths you can go by, but in the long run, there's time to change the road you're on."
I think that was said to a young lady climbing the stairway to heaven, if I'm not mistaken...
I've never heard of this but sure glad I read your post in case any such scam comes to Nova Scotia. Thanks.
Tina - I have understood that Nova Scotia is not as cold as people imagine because of the Gulf Stream, but still, I expect that there any radiant barrier would likely be of little benefit. More insulation would though!
I've not heard of paint as a radiant barrier, good to know that it is not true Jay.
Maybe it's a new scam cause that will sweep the nation Tom. Usually such energy-saving drivel begins west and moves east, but maybe not in this case!
Jay, Yeah I am not convinced on radiant barriers either.
I've done a lot of reading since this discovery, Don, and I can't see where they can have an effect when there is really so little affective radiant heat.
How ridiculous is that? LOL, I'm in the wrong business!
Just another scam to separate honest home owners from their money.
Not only may that be completely useless, but they may also lead some to the conclusion that there was a fire, hence the reason for the trusses to be painted...as I once learned from a very smart Bristow home inspector I know.
Hi Jay - This one hasn't made it to our area yet, at least that we've heard. Thanks for the heads up!
Thank you for this information. Great to know.
Fred - partnership?
Stephen - yep. That's what I said at the inspection!
Can't think who that might be, Chris Ann, but I checked for that under the paint.
Dick - perhaps you are next on the list.
Any time Linda! I may stick around.
Paint for insulation is a new one on me Jay Markanich. Thanks for the heads-up
It's going on Deanna! Apparently this guy is getting around.
I hope that your advice sill save money for many consumers.
That is the idea Roy. This may be a scam to come to a neighborhood near you!
I have a laundry room that has no insulation and would be blazing hot in the summer, raising the temperature of my already warm TV room which shared a wall. I used a similar type of paint on my roof and it was night and day difference from the instant the paint went on! I was amazed and so was my painter!
I almost did this in my attic too! My attic gets really hot in the summer (over 130 degrees). My attic floor has all the insulation and keeps my house nice, but the attic (where I store old clothes and stuff) was way too hot. I put in an attic fan which dropped the temperature some, but never got around to painting the ceiling due to concerns over what it would do to cell phone service (which is already almost non-existant).
Just reporting the RIMA facts, Ryan. I've never heard that paint could influence cell phone service. Very interesting! I'll have to look into that one.