Radiant Barrier slows heat transfer into your attic
What Is Emissivity?
- This word describes the ability of a material to emit heat.
- Every material emits heat. Some more than others.
- The wood underside of your roof gets hot and emits heat into the attic.
- Wood is a "good" emitter of heat, with an emissivity rating of about 0.85.
- Radiant barrier is a "poor" emitter of heat, with an emissivity rating of about 0.19.
- Radiant barrier material itself gets hot but doesn't emit or radiate heat like wood does.
There Are Two Basic Types of Radiant Barrier
FoilLower emissivity rating than paint typeMaterial is less expensive than paint typeMuch more labor intensive to installOverall cost is generally higher than paint type
PaintOverall cost is lower than foil typeEffective to install in difficult atticsEmissivity is higher than foil typeLess labor is required for installRequires a spray rig