First it should be stated that radiant barrier or low emissivity paint is not an insulator. It's an infrared radiation blocker. But what is infrared radiation? Basically any time that you sit infront of a sun filled window and feel the extra heat, that is infrared radiation. If you ever have seen heat radiating off a hot stretch of highway that also is infrared radiation. Infrared radiation is a wave of heat from the sun that has a tendency to excite the molecule in a material, causing the material to heat up. And radiant barriers help reflect those waves away from your home.

Radiant barrier paint is actually a low emmisivity paint. In order for the paint to be a true radiant barrier, the material used has to block 95% of the sun's infrared rays. Heatbloc-75 blocks 75% of this infrared radiation from entering your attic area. In turn keeping your attic cooler than homes that lack this type of protection.

HOW TO INSTALL RADIANT BARRIER PAINTS IN YOUR ATTIC

Heatbloc-75 is 22% more effective than it's closest competitor. Heatbloc-75 and other low emissivity paint is composed of small chips of aluminum and ceramic that is mixed with a bonding agent that allows it to stick to material; like your roofs decking. It's these chips of aluminum and ceramic that prevent the sun's infrared radiation from entering into your attic area. Did you know that infrared radiation can cause your attic to heat up to temperatures in excess of 130 degrees during hot summer months? Applying Heatbloc-75 or other low emmisivity paints can reduce that additional radiant heat by as much as 75%. But if blocking 75% of the suns infrared heat isn't enough, other more effective materials are out there.

Radiant Guard which is a true radiant barrier material reflects up to 97% of the suns infrared radiation. This material should be applied to the attic rafters in the South. Not on top of your attic insulation. Although applying this material on the floor is helpful in the North it is not as helpful in the South. Why? Remember up North the objective is to keep heat inside the home during the winter months. So this material helps reflect the radiant heat inside a home back into the home. In the South our objective is to keep the heat out of our homes and that includes the attic. Especially because most homes in the areas like Charleston, San Antonio, Tx have the A/C duct work running through the attic. So installing this material on top of the insulation in your attic will help keep the heat out of your home, but won't really do much to keep your duct work cooler. So installing Radiant Guard on the ceiling of your attic is better for the Southern parts of the United States like Pensacola, FL or Savannah, Georgia. But keep in mind that installation of this material is much more difficult.

The Basics RADIANT BARRIERS

So do you need radiant barrier? Well nature's natural radiant barrier are trees. If your home is well shaded, then you probably do not need radiant barrier. But if your roof is exposed to the sun most of the day, then you may want to consider applying a low emmisivity paint or installing radiant guard to the ceiling of your attic. These radiant barriers and low emmisivity paints can help reduce your utility bills in the hot summer months. Check out the link RIMA International comparing all low emmisivity paints and radiant barriers to find the product that is right for you.

RIMA International Thermal Coating Study