What are the disadvantages of reflective foil insulation?

Author: Prof. Kellie Spinka PhD  |  Last update: Saturday, February 28, 2026

It is generally more expensive due to being a metal-based product. It is also important to note that in order for foil insulation to work correctly, it must be kept free of any dust. This means in some areas, such as roofs, it may require being cleaned of dust from time to time to ensure maximum efficiency.

Is reflective foil insulation worth it?

The use of foil insulation reduces energy expenses by limiting air conditioning usage during peak times. In winter, it retains heat by reflecting heat indoors whilst limiting heat loss through the roof or walls.

Does foil insulation keep cold out?

Foil insulation is known as an extremely effective way to keep your home warm and to cut energy costs at the same time.

What are the problems with radiant barrier insulation?

Moisture problems, air leaks, inadequate attic ventilation, dust accumulation, compatibility issues with existing insulation, and condensation are some of the common challenges associated with radiant barriers.

Does foil insulation need an air gap?

Foil insulation is particularly effective at reflecting radiant heat, which can be beneficial in both summer and winter. However, in order for it to work effectively, there needs to be an air gap between the foil layer and the surface it's installed on.

Reflective Bubble Foil Insulation/Does It Work???

Does foilboard need an air gap?

Does Foilboard need an air gap? In most applications, foil insulation requires an air gap of at least 25mm in order to insulate effectively for radiant heat. Installed without an air gap, and the effective R value of the boards will be close to zero.

Do you need a vapour barrier with foil insulation?

Typical insulation works in a basement but you have to use a good vapour barrier along with it. This is where foil faced insulation takes its place. The best way to insulate a concrete wall is with foil faced rigid foam boards.

What are the cons of foil insulation?

It is also worth to point out 3 main disadvantages of foil faced insulation such as:
  • It is generally more expensive due to being a metal-based product.
  • It is also important to note that in order for foil insulation to work correctly, it must be kept free of any dust.

What is the difference between radiant barrier and reflective insulation?

Radiant Barrier In Walls. In your handbook you explain the difference between a reflective insulation and a radiant barrier essentially being that with the former, the foil is facing an enclosed air space, whilst with the latter the foil is facing an open-air space.

Does radiant barrier affect WIFI?

With Wi-Fi signals, unless the radiant barrier is between you and the router, there is unlikely to be any impact.

Is it illegal to put aluminum foil on windows?

Emergency management agencies specifically recommend using aluminum foil-covered cardboard that goes between windows and drapes.

Is foil insulation better than fiberglass?

Fiberglass passively blocks heat transfer due to the poor thermal conductivity characteristics of its glass fibers. Radiant barrier foil, on the other hand, actively prevents heat transfer using its thermal radiation properties. Learn more about these insulation options to identify the best one for your building.

Does foil insulation cause condensation?

Because foil insulation reflects warm air from entering, a mixture of hot air and cold air cannot create condensation.

Where do you put reflective foil insulation?

Where To Use Foil Insulation
  1. Pole barns that house animals.
  2. Workshops and garages.
  3. Storage units.
  4. Equipment sheds.
  5. Recreational vehicles like motorhomes or campervans.
  6. Transportation trucks.
  7. Cargo liners.
  8. Inside roof trusses or rafters.

Is reflectix better than fiberglass insulation?

1 With fiberglass insulation R-values ranging from R-15 to R-19 for two-by-four wall systems, Reflectix appears to be a better insulating material than fiberglass or other thick, dense materials.

How long does reflective insulation last?

As long as homeowners or certified attic specialists install them appropriately, radiant barriers last anywhere from 80 to 100 years. They are built to last and won't cause significant issues for decades.

Does a radiant barrier need an air gap?

These are the exact same principles that apply to installing a radiant barrier in any assembly. You MUST have an air gap in order to get either the emissivity quality or the reflectivity quality that you're looking for, otherwise the foil will not work as a radiant barrier.

What R-value does reflective insulation have?

In short, reflective insulation can have an R value anywhere from R-3 all the way up to R-17.

Does reflective insulation really work?

If you're planning a home remodel, reflective foil insulation is an option that you should really consider. It's highly effective at reducing heat transfer, easy to install, thin and lightweight, and can help prevent moisture buildup and condensation.

What are the disadvantages of foil?

Health Risks of Aluminium Foil
  • Leaching of Aluminium into Food: When food is wrapped in aluminium foil, especially hot, acidic, or spicy foods, aluminium can leach into the food. ...
  • Kidney and Bone Damage: Prolonged exposure to aluminium has been linked to kidney and bone damage.

Does reflective insulation keep cold out?

Reflective, radiant-barrier insulation is usually made of aluminum foil with a variety of different backings, including plastic film and cardboard. This type of insulation is most effective in warmer climates, but can also be used for comfort and energy savings in cold weather.

Can foil insulation get wet?

Reflective foil Insulation

However, long-term saturation and submersion in water can impact the effectiveness of the reflective foil surface. Additionally, when exposed to moisture for extended periods, oxidation of the foil can occur leading to a loss in thermal resistance.

When not to use a vapor barrier?

Don't: Put Vapor Barriers on the Bottom of the Floor Joist in the Crawl Space. Because vapor barriers are good at retaining moisture, putting plastic sheeting on the joists can cause moisture to build up under the floor.

Do radiant barriers work in attics?

A radiant barrier reduces the radiant heat transfer from the underside of the roof to the other surfaces in the attic. A radiant barrier works best when it is perpendicular to the radiant energy striking it.

Which side of reflectix faces out?

An air space must exist on a minimum of one side of the product (always on the reflective side (residential attic – preferably oriented facing down)). Radiant barriers by definition do not require an enclosed air space to provide benefit. This application (radiant barrier) is typically installed in a ventilated attic.

Previous article
Will new bubble wrap not pop?
Next article
How to choose the color of a carpet?