How Does Radiant Barrier Work?

The term radiant barrier refers to a reflectivethermal radiation that passes through your
coating that is typically applied to the underside ofinsulation and makes your house warmer. Radiant
the roof, there are however several differentbarrier is primarily designed to keep heat out and
types and different ways that it can be installed.does not show significant benefits in reducing
The two major types are spray on and sheetheating costs for people living in cold climates.
barriers. Sheet radiant barrier comes in large rolesThat being said, it can make a major difference
that you then roll out in your attic. This can be laidon roofs in southern states and dramatically
directly on top of your insulation, nailed to thedecrease your cooling bills. The reflective metal in
bottom of the roof, or hung from your rafterthe barrier will prevent the heat on the outside of
supports. This is also the type of radiant barrieryour roof from the sun turning your attic into an
that is sometimes used underneath shingles. Inoven. No amount of insulation can totally prevent
new construction or re-roofing projects you canheat transfer, and the higher the temperature
roll out sheet radiant barrier on top of the roofdifference the more heat transfer their will be. So
but under the shingles.by decreasing the temperature in your attic you
The second kind of radiant barrier is spray on,make it easier for your insulation to do its job and
which is sprayed onto the underside of the roofkeep the cold air in and the hot air out.
like paint. This has the advantage of being moreMany people feel that if there house has
durable and easier to install correctly. It is in fact aadequate insulation they either do not need, or
paint mixed with metal flecking that provides thewon’t see much benefit from, installing a
reflective property required to reflect the heat.radiant barrier in their house. This is not true
Another advantage of spray on barriers is thatprimarily because radiant barriers and traditional
they are easier to get total coverage with asinsulation function very differently in how they
compared to the sheets. However, there is onekeep your house warm. Radiant barrier prevents
drawback to spray on radiant barriers, they dothe transmission of heat radiation into the air
not provide quite as much heat shielding asaround it, it stops heat that is radiating into your
properly installed sheets can. However, manyattic space from outside. Traditional insulation on
experts feel that you will see just a much benefitthe other hand primarily serves to trap air, thus
from spray on radiant barrier due to its greaterpreventing heat transfers due to air movement
durability and ease of installation over the entireknown as convection. So even if you have
surface of the roof.adequate traditional insulation preventing
Both of these radiant barriers function on theconvection warming of your house from your
same basic principle. Reflecting heat away fromattic, you can still benefit from adding a radiant
your house will keep heat away from yourbarrier to prevent heat radiating into your house
insulation, which in turn will lower the amount offrom outside.