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  • Writer's pictureAmerican Insulation

Does Foil Insulation Really Work?


Are you wondering whether or not radiant barriers really work? If so, you are not alone. Many people want to understand this important aspect of insulation. A radiant barrier performs the task of reducing the radiant heat transfer from the underside of the roof to the other surfaces in the attic. Radiant barriers typically work best when they are perpendicular to the radiant energy that is striking it. If you live in a warm, sunny climate, you can certainly stand to benefit from reduced cooling costs. Your cooling costs could go down as much as five to ten percent.

When to use foil insulation

Foil insulation tends to work best in areas where space might be too restricted to use other types of insulation. This type of insulation is also best used in hotter climates, where it will best reduce the radiant heat coming off the underside of your roof. It will also retain heat better when the weather cools off.

What is the purpose of foil faced insulation?

Installing foil-faced insulation is good if you want to reduce radiant heat in your attic. Unlike other insulation, it doesn’t absorb heat. Instead, it has stronger reflective properties to reduce heat. It’s also useful for noise reduction. Typically, foil insulation is installed with the foil side facing the warm air surface. The foil reflects the heat toward the interior of the building. It will reduce heat radiation in the summer and retain it in the winter.

Can foil faced insulation be left exposed?

When installing foil-faced insulation, it cannot be left exposed. This is because the foils used in it are often combustible. Leaving the insulation exposed can create a fire hazard. When the installation is installed, it should be in contact with an approved ceiling, wall, or flooring material. There is only one type of flame retardant foil insulation—FSK-25—that can be left exposed.

Is foil insulation flammable

Although foil insulation can be valuable in hot climates if it is not installed correctly and left exposed, a fire hazard is created. Not all foil materials, however, are flammable. FSK-25 materials are flame retardant. Many other types of insulation are not combustible but can smoke and release toxic chemicals. One of the chief risks with the combustible materials is the heat increase when there is a fire. This heat increase accelerates fires. Also, the more insulation there is in a room, the higher temperature a fire will be. Insulation wrapped around wiring or other heat-producing devices puts those materials at greater risk of overheating.

Is foil insulation waterproof

One of the advantages of foil insulation has over other types of insulation is that it is largely waterproof. It also serves as a vapor barrier. If there is a roof leak or plumbing leak, the foil is less likely to degrade or develop mold and mildew.

Can you paint over foil insulation?

If you want to paint over foil insulation, you can, although because it is non-porous, it’s less adhesive so you will have to follow some steps to make sure the paint stays on. Before you attempt to paint in an area that might be poorly ventilated, you’ll want to wear a respirator.

  • First dust the foil face using sticky tack cloths.

  • Make sure to protect the area around the insulation with painters tape and drop cloths.

  • Use a roller to coat the foil with a water-based metal self-etching primer.

  • Smooth the primer with a polyester paintbrush to ensure there are no flaws.

  • Let the primer dry for about four hours.

  • After you wash the brush and roller, coat the foil with satin or semi-gloss latex paint with the roller.

  • Smooth the paint with the brush.

  • Wait two hours to let the paint dry.

What is the best foil insulation?

There are many good brands of foil insulation on the market today. Several of them consistently get ranked highly by professionals. Some of those include:

  • RadiantGuard Reflex-Air

  • Reach Barrier DD48025

  • Infrastop Double Bubble

  • Reflectix ST16025

  • Insulation Market Place Shield

  • Reflectix BP48010

  • AES Radiant Barrier

Call us today (817) 592-6900. We are here to help.

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