A homeowner on her cellphone points to the ceiling where radiant barriers are to be installed, suggesting some sort of installation issue

A radiant barrier is an excellent and innovative way to control the temperature inside your house. They are also great for helping you lower your cooling costs.

According to the U.S. Department of Energy, radiant barriers can decrease cooling costs by 5-10%  when used in a sunny and warm climate. 

Nevertheless, there are some problems and issues that a radiant barrier can bring.

Some of these complications can arise due to the environment, whereas other issues can result from faulty installation.  

In this article, we will look at some of the problems that can come up with radiant barriers, along with solutions and preventative techniques.

Potential Problems with Radiant Barriers

There are five potential issues when installing a radiant barrier in your house, but the primary three include ventilation, condensation, and dust. 

These last three are related because lack of proper ventilation can cause the barrier to result in condensation or dust accumulation.

Such problems can either damage your house or lower the effectiveness of the radiant barrier itself. 

1.) Dust 

Dust is a significant problem that can develop with radiant barriers as it prevents reflective insulation from working optimally.

Once the barrier material gets polluted with dust, it loses its reflective abilities, allowing sunlight to penetrate your roof and increase the temperature inside your house. 

Fortunately, there are plenty of ways to overcome these issues. For instance, you can use spray-on radiant barriers that are very similar to paint.

However, the spray-on radiant barrier is applied directly to the underside of the roof decking. Thus, it becomes impossible for dust to accumulate on the heat reflective surface. 

2.) Inadequate Attic Ventilation 

Ventilation in the attic can have a considerable impact on the performance and effectiveness of the radiant barrier. 

Without sufficient attic ventilation, the radiant barrier produces a thermos effect. This trapped air can make your attic even hotter than it was without the technology. 

For proper and effective ventilation, building codes mention that there needs to be 1 square foot (0.09 square meter) of net free ventilation area per 150 square feet (13.94 square meters) of attic floor.

This ratio might be reduced to 1 to 300 if a ceiling vapor retarder is installed or low (soffit vents) and high (gable or ridge vents) attic ventilation is used.

As part of the vent area is blocked by louvers or meshes, the net free area of a vent is less than its total dimensions. 

A diagram demonstrating how net free ventilation works
How net free ventilation works. Courtesy of Pro Home Improvement

Nevertheless, you should talk to your insulation expert and ask them to calculate the ideal level of ventilation based on your attics’ size, shape, and volume. 

Another great solution to overcome the ventilation issues with radiant barriers is to install an attic fan.

When you have a high-powered electric fan, you won’t have problems with excess heat in your attic. 

You can either install an electric-powered fan or go for a solar attic fan if you wish to save electricity.

However, consider that solar fans have less power and a shorter lifespan than electric fans.

Moreover, if your attic isn’t sealed correctly, these attic fans can circulate mold, pollen, pet dander, and dust into your living areas and allow cool air to escape.

Such pollutants can harm your home’s indoor air quality and make you and your family feel sick.

Unfortunately, many people fail to realize how they affect a healthy home environment. 

3.) Condensation 

Moisture can be a problem when a radiant barrier is installed on the attic floor directly above fiberglass or thermal insulation.

During the cold winter months, water vapor inside the house might enter the attic. 

If your attic is adequately ventilated, the condensation won’t cause any problem.

However, due to inadequate ventilation or extremely low temperatures, a radiant barrier above the insulation can cause the water vapors to condense on its underside. 

Excessive condensation can result in the following problems:

  • The existing insulation becomes wet and loses some of its insulating potential. 
  • Water spots form on the ceiling. 
  • The ceiling framing begins to rot. 

One precaution for preventing potential moisture problems is naturally permeable or perforated barriers. The higher the perm rating, the fewer potential problems that arise. 

Other additional precautions include avoiding high indoor relative humidity, sealing air leaks and cracks in the ceiling, and using a vapor retarder underneath the attic insulation. 

4.) Increase in Roof Temperature

Radiant barriers can increase your roof’s temperature by up to 10 degrees when installed on the underside of the roof.

Many contractors prefer this installation technique as it allows for a neat installation. 

Nevertheless, if you have adequate attic ventilation, you don’t need to be concerned about radiant barriers increasing the roof temperature. This is particularly true for hot and arid states like Arizona, where roofs are already at around 140°F (60℃).

To overcome this problem, many radiant barrier contractors install radiant barriers on the attic floor and use the highest-powered attic fans to ensure your attic stays a couple of degrees higher than other rooms in your house.

5.) Might Not Be Effective When Used Alone

Radiant barriers can successfully prevent heat gain due to radiation.

However, they cannot stop heat gain that happens due to convection or conduction. Because of this reason, you might have to use thermal insulation in combination with fiberglass or thermal insulation, especially in your attic. 

Benefits of Correct Radiant Barrier Installation 

Radiant barriers are susceptible to some problems.

But keep in mind that no technology is immune to user error, environmental stressors, or deterioration. 

The benefits of radiant barriers generally exceed the potential costs that these problems can result in. 

By installing a radiant barrier in your home, you get several benefits, including:

Comfort Throughout the Year 

Radiant barriers ensure that your home’s temperature stays comfortable throughout the year. 

Their primary function is to stop heat from entering your house and increase temperatures inside your attic. Without radiant barriers, direct sunlight can heat your space pretty quickly. 

Sunlight penetrates inside your house directly through transparent openings such as windows. Nevertheless, it also enters indirectly through impermeable surfaces like walls and roofs

A radiant barrier blocks heat from entering your house by preventing heat gain due to radiation.

Other types of insulation work differently—they slow down heat gain due to convection and conduction.

Thus, radiant barriers are quite distinct from other kinds of insulation. In fact, the hotter it is, the better they will work. 

Lastly, radiant barriers don’t just keep the heat out of your house—they also retain it inside. During winter, they prevent heat from escaping.

Instead, they redirect it to other rooms in your home, which allows for uniform comfort throughout your home. 

Higher Cost-Efficiency 

If your attic is cool, your entire house will be cool. 

By decreasing the temperature inside your attic, radiant barriers can diminish costly cooling measures, such as air conditioning.

Reduced use of air conditioning means higher energy savings. 

What’s great is that radiant barriers don’t just increase energy savings in the short run by reducing AC use—they also play a significant role in lowering long-term maintenance costs

High temperatures can cause wear and tear on AC units by making them work twice as hard. Moreover, they also put pressure on cooling systems by forcing extra cool air via your ductwork.

The additional cool air consequently results in debris accumulation, which reduces the life of your air ducts.  

Moreover, as mentioned, radiant barriers optimize your heating during colder months. This optimization means you don’t just get comfortable temperatures inside your home but also benefit from reduced energy bills throughout the year

Longer HVAC System Lifespan

Radiant barriers contribute to the longevity of HVAC systems indirectly. By reducing the workload on these systems, they experience less wear and tear, leading to a potentially longer lifespan. 

This benefit can translate to lower maintenance costs and a reduced likelihood of having to replace HVAC components prematurely.

Environmental Benefits

Energy-efficient practices, such as correct radiant barrier installation, contribute to a smaller carbon footprint

When homes are more energy-efficient, they require less electricity for heating and cooling, thereby reducing overall energy consumption.

This not only benefits individual homeowners but also contributes to broader environmental conservation efforts by lowering the demand for energy production and its associated environmental impacts.

Last Few Words

Radiant barriers offer a range of benefits depending on factors such as the temperatures in your area, your home’s exposure to the sun, etc.

For instance, if you are a resident of San Diego, you will notice a significant decrease in your electric bill once you install a radiant barrier. 

Radiant barriers also help save energy by stopping heat from entering your home during summer and retaining heat during winter. This efficiency means you can enjoy considerable savings on your electric bill. 

Moreover, radiant barriers can even increase the efficiency of your HVAC system, minimizing long-term maintenance costs. 

Nevertheless, to achieve these benefits, you need to make sure you avoid the problems listed above. 

Ideally, you should contact an experienced and licensed radiant barrier contractor to install them in your home. These professionals will ensure that the barriers are installed correctly.

In addition, they can also provide repair and maintenance services so that your radiant barriers continue to work optimally and keep all potential problems at bay!

One Comment

  1. We had a licensed contractor install radiant barrier on the underside of our roof. A roofing contractor peeled off the old roof and tar paper and, installed a new type of protective layer onto the 4×8′ wood before installing new asphalt roofing and 11 new dormers (Hanson).
    The roofer did not initially cut the radiant barrier under the 4×8 plyboards until I asked him to do so. He hesitated. Who’s right?

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