5 Reasons Why You Shouldn’t Have Radiant Barrier Paint Sprayed in Your Attic
Radiant barrier paints are the newest offering for insulating your attic. However, there are a lot of problems that come with this new service offering from your local insulation company. Here are 5 reasons why you shouldn’t have the paint sprayed in your attic.
1. Paints and Sprays Aren’t Radiant Barriers
According to the ASTM definitions of a “radiant barrier” and the FTC definitions of “home insulation”, the paint products on the market qualify as neither. The most efficient of these paints/sprays are called “interior radiant control coatings” or IRCCs, but some so-called radiant barrier paint products do not even meet the efficiency required to be called an IRCC. So how does this affect the consumer? Simply stated, the paint additive or spray coating products do not meet the same building requirements as the radiant barrier and do not qualify for the same energy efficiency credits.
“Currently, EPA does not label paints and coatings for the inside of roof decks (or attic) in the insulation program because paints and coatings do not meet the Federal Trade Commission (FTC) definition of ‘home insulation.'” -ENERGY STAR
Because Energy Star uses the same requirements as the FTC for insulation and energy efficiency, these radiant barrier paints/spray coatings are not included in the radiant barrier requirement for Energy Star homes. In some cases, there are tax credits or energy credits available for radiant barriers, like recent IRS tax credits and energy credits through various cities, municipalities, and even utility companies, for which paints will not qualify. If you are looking to qualify for rebates like these, or have building requirements to meet, you need to be using a true radiant barrier foil.
2. Radiant Barrier Paint / Spray Is Less Efficient
According to a RIMA International study, an association made of manufacturers of radiant barrier Houston, Tx, reflective insulation, and radiant barrier paint additives/spray coatings, paint products on the market have a wide range of efficiency and energy savings. Some of these paints only block out only 10%-14% of the radiant heat, and some block up to 64%-85% of the radiant heat. All true radiant barriers start off at a minimum of 90%. Even the most expensive paints with higher efficiency may cover a smaller area, further reducing the efficiency. The paint is typically sprayed directly to the underside of the roof decking, leaving the roof rafters uncovered. There is nothing to stop these wood rafters from emitting radiant heat directly into the attic insulation. Assuming the rafters are 1.5″ wide and are spaced 24″ on center, then even the best, most expensive insulation paints / sprays only block 59%-78%.
Additionally, paints are not always sprayed consistently or evenly across the roof decking. It is easy to see areas that have a thinner coating because the wood can often be seen through. There have even been cases where installers realize at the last minute that they didn’t bring enough paint for the whole roof, and do a thinner coat or dilute the radiant barrier paint with water to stretch it further. Since foil insulation is installed across the bottom of the roof rafters, and is made with a sheet of pure aluminum it will always block 90% of the heat or more.
3. Your Radiant Barrier Paint May Not Last
When a dirty, older wood surface (like a roof deck) is painted, nearly any paint manufacturer or professional contractor knows that the surface should be cleaned, sanded, primed, and coated with multiple coats of paint. These steps are Painting 101 to ensure that the paint adheres to the surface and doesn’t peel or fade. Yet these basics are completely ignored by most paint/spray installers.
If the paint coating is sprayed on the roof decking without cleaning off the dirt and debris, and sanding down the surface, painting over dirt and debris can result in poor adhesion and may lead to an uneven coating. This is the primary reason that paints crack, chip, peel, and fade after just a few years time. Applying a primer over a clean, smooth surface is essential because it not only increases the durability of the paint but provides a smoother surface to improve the reflection and overall performance of the paint. Finally, when you need a consistent, even covering over wood, then multiple coats of paint are often necessary.
4. Radiant Barrier Paint May Contain Hazardous or Toxic Chemicals
For chemically sensitive or hypersensitive homeowners, a radiant barrier paint product may not be an option. Homeowners who are not chemically sensitive but are still concerned about a toxic or hazardous product being sprayed right over their heads, right near their ventilation system, should look closely at the product’s MSDS sheet. Many of these paints contain chemicals that can prove hazardous when in contact with the skin, eyes, nose, and throat.
Due to some of the hazardous chemicals contained in radiant barrier paint products, manufacturers recommend that the installer wear personal protection like an impervious protective suit, a pair of ANSI-approved safety glasses, and a NIOSH/MSHA-approved respirator. In fact, RIMA-International has issued a safety statement saying that these products may “contain hazardous chemicals or emit fumes, which can enter the body through inhalation, skin absorption, or injection into the eyes, nose or throat.” Before use, consult the manufacturer’s MSDS sheet.
5. Radiant Barrier Paint / Spray Coatings Are Difficult to Do Yourself
Unlike the sheets or rolls of real radiant barrier foil or metalized films, paint/spray coatings have special installation requirements. ASTM C 1321 describes special procedures that need to be taken to ensure the products are applied properly and that the product does not damage the surface to which it is being applied.