Insulating Paint: Does It Work?
The promise of adding significant R-value to your home walls and ceiling with a coat of paint is certainly attractive. No ripping walls apart. No contractors. Little cost. Quick. Easy. Effective. Let’s dig a little deeper into this paint product.
What is Insulating Paint?
Insulating paint was developed by NASA as a coating to protect the space shuttle from the heat of re-entry into the Earth’s atmosphere. Micro-spheres with a reflective coating are mixed with paint. It reflects 90% of solar infrared radiation and 85% of ultraviolet radiation from a surface.
Insulating paint works like reflective insulation by preventing solar gain inside a building. It works in both directions–reflecting heat away from the building and helping to keep heat inside a building.
Insulating paint is available as a premixed product or as an additive. The additive is powdered micro-spheres that turn regular paint into insulating paint. NASA did collaborate with one company to market a microsphere paint additive.
Premixed insulating paint sells for around $40.00 – $55.00 per gallon. Enough additive product to treat one gallon of paint is about $18.00 – $22.00.
Insulating paint products have been sold for over 25 years. Some of the claims include:
- At least one company claimed its product was the equivalent of 7” of fiberglass. The Federal Trade Commission (FTC) took exception.
- Reduces heat gain by 50%, or 30%, or 20% depending on which ad from the same company.
- Equal to R-100 insulating value. The FTC won a court case on this one and imposed hefty fines.
- Reduces heating costs by 40% – 60%.
Insulating Paint Studies
To date, no insulating paint manufacturer has produced any independent studies that prove their claims. No existing scientific methodology proves increased value over regular paint.
No US, British, European, or international standard exists to measure the insulating properties of paint. Anyone buying and using insulating paint has to decide whether or not to trust the manufacturer’s claims.
Insulating paint has zero R-value. Even the product manufacturers admit there is no method available to measure it.
Exterior Insulating Paint Facts
Exterior insulating wall and roof paint does have the following benefits:
- Solar reflection. Reflects up to 90% of the sun’s heat.
- Breathable. Water vapor can escape through the paint–keeping the substrate dry.
- Hydrophobic. Resists dirt and dust attachment.
- Multiple colors.
Any good light-colored paint reflects heat. There are many types of roof coatings available with similar properties.
A quick and admittedly cursory Google search shows that insulating paint and additives are “currently unavailable” on Amazon. Home Depot and Lowe’s do not carry them. Which might lead one to believe the value of the products is questionable.
Much of the thermal paint and additives are manufactured overseas and imported. Also, many manufacturers have changed the name of their products or companies or offer the same products under different names.
Insulating paints appear to be of some benefit as a reflective coating when applied to the exterior of walls and roofs in sunny or hot climates. Not so much as an interior insulation product.