In this post, we’ll give an in-depth look at the pros and cons of radiant barrier sheathing insulation versus spray-in foam insulation. Which one is the clear winner?
Table of Contents
First, you need to understand how heat is transferred.
There are three types of heat transference:
Spray in foam: protects against conduction and convection heat.
Radiant barrier: exclusively protects against radiant heat.
You might be wondering “Why not combine the two forms of insulation and get the best of both worlds? It’s because it will negate the effectiveness of radiant barrier sheathing.
Cellulose insulation will block the radiant barrier from absorbing any heat or radiating it out.
Factor | Radiant Barrier Insulation | Spray Foam Insulation |
---|---|---|
Material | Reflective material, usually aluminum foil | Liquid foam that expands and hardens |
Coverage | Reflects radiant heat | Creates an airtight seal |
Effectiveness | Reduces cooling costs by up to 10-15% | Reduces heating and cooling costs by up to 50% |
Application | Mostly used in attics and roofs | Can be used in walls, floors, and other areas |
Cost | Generally less expensive than spray foam insulation | Generally more expensive than radiant barrier insulation |
Versatility | Limited in application | Can be used in a wider range of applications |
Noise Reduction | Does not provide noise reduction | Provides noise reduction |
Indoor Air Quality | Does not improve indoor air quality | Can improve indoor air quality |
Light, durable, and inexpensive—radiant barrier insulation works effectively to reflect heat off its surface, despite having little to no “insulation” properties (no R-Value).
It’s even used by NASA to reflect thermal radiation and keep temperatures inside of a ship regulated.
The material has a metallic sheen that is similar to what you’d see on aluminum foil.
It can reflect up to 97% of heat radiation. According to the U.S. Department of Energy, after installing radiant barriers in your attic, temperatures can decrease heat gain by 40%, usually around 30 degrees, which can mean a 17% reduction in your heating bill.
Typically, radiant barrier sheathing has a limited scope of application. It’s mainly used in attics or crawl spaces.
However, the material can be used on the walls outside of a home to reflect heat, or on the gables, which are the triangle-shaped portions of a wall between the edges of intersecting roofs.
Two styles of radiant barrier sheathing:
If you want to insulate your attic, you absolutely need to use a perforated radiant barrier since this will protect your space from moisture-heavy air. If you need more airflow, breathable perforated radiant barrier insulation is the preferred option.
On the other hand, a solid vapor barrier (no holes) is preferred in northern climates or coastal areas with a lot of moisture and water exposure.
The most common types of radiant barriers include:
Spray in cellulose foam insulation is sprayed in as a liquid substance that congeals to a surface, creating an airtight seal that prevents the transmission of heat in and out of a space.
When there are roof trusses, things get more complex. It becomes difficult to identify leaks in your roof after you’ve applied spray foam. This is because it is glued directly to the area and can end up soaking moisture from the roof decking.
Spray-in foam insulation is used in most places around a home:
It’s the perfect choice for filling in floor crevices, gaps, joists, and corners. The tight, compact seal creates higher insulating properties, eliminating cold drafts, reducing air leaks, and creating a temperature-regulating atmosphere.
(For a detailed R-Value chart, read “Insulation R-Values Chart and Buyer Guide.”
Open Cell Spray Foam
Closed Cell Spray Foam
Spray Foam Comes in 3 Categories
Radiant Barrier: $740 to $2,840
Prices can range from $0.15 to $0.75 per square foot, depending on the brand you choose and the method of installation.
Spray Foam: $1,284 to $3,741
Price ranges depend on the thickness and density of the foam. It can cost anywhere from $1.50 to $3.50 per square foot.
Here’s a case study of an award-winning home that incorporates GPS foam in its structural insulated panels (SIPs) and Icynene spray foam in the floor. The result is a home that is net-zero energy and offers healthy indoor air quality.
In this case study, learn how to use radiant barriers to insulate an attic.
If you’re unsure what insulation type to use for your property, consult with a professional to see what building codes are required. Your best bet is to contact your municipalities building department. They can provide you with the latest code information for your area.
Both radiant barrier sheathing and spray-in cellulose foam insulation offer advantages and disadvantages. Before you buy, remember to review factors like your budget and building code requirements.
All in all, if you’re willing to invest in it, spray-in foam offers the better choice for insulation. It’s more versatile and offers a higher R-Value, leading to better energy efficiency and can generate a solid long-term return on investment.