Getting to Know Radiant Barriers

The purpose of a radiant barrier is to reduce summer heat gain and reduce cooling costs. This is achieved by installing the highly reflective material, normally in your attic, so that it can reflect the radiant heat rather than absorbing it.

A radiant barrier’s effectiveness is dependent on both the type of radiant barrier and the proper installation. The Oak Ridge National Laboratory estimates the air-conditioning cost savings can range from about $150 annually for very hot climates to only $40 for cold climates and installing the barrier incorrectly or choosing the wrong product can prevent you from reaping those savings. Some consumers end up disappointed with the effectiveness of their radiant barrier and this is mostly because of improper installation and poor choice in product so it’s important to do your research.

It is best to use a certified installer but if you choose to do the installation yourself, carefully study and follow the manufacturer’s instructions and safety precautions and check your local building and fire codes. The reflective insulation trade association offers installation tips.

​The most important decision in the process of installing a radiant barrier in your home is the product that you choose to invest in. Radiant barrier paint, radiant barrier chips and radiant barrier foil are the three types of radiant barriers.  We do not support radiant barrier paint or radiant barrier chips but do support the use of radiant barrier foil.

Radiant barrier paint

Radiant barrier paint is meant to be a paint that is reflective and can simply be painted onto a surface to reflect radiant heat. There are a few flaws to the product. Radiant barrier paint can be diluted in the field with water and will lose its effectiveness when applied.  I’ve seen many houses where the radiant paint looks more like gray paint rather than a reflective paint, which is a sign of dilution. In fact, radiant barrier paint is technically not even a radiant barrier, because its reflectance is only 75%.  Radiant barrier paints also has lower performance standards with higher emittance values and lower reflectance values than traditional radiant barrier foils.

Radiant barrier chips

Radiant barrier chips are flakes of a reflective material that is scattered throughout the attic. The problem with radiant barrier chips is that installers usually do not install them with enough density to cover the entire surface area of the attic. The chips need to be several layers deep and must be evenly spread which bring us to the other issue of the chips being very easily moved. 

Radiant barrier foil/sheathing

Radiant barrier foil is a sheet or board that is covered with reflective material. The radiant barrier foil comes either in single or double sided. Some foil may be breathable with ventilation holes. Some radiant barrier foil may also have a foam core with some insulation value to it. This type of radiant barriers, meeting certain criteria, can in fact be classified as insulation under the EPA, qualifying them as ENERGY STAR products.  We support this method of radiant barrier because it’s the most effective, maintenance free, long lasting, and reliable.