Radiant Barrier Insulation
Radiant barriers are not traditional insulation and do not have an R-value. Instead, they work by reflecting radiant heat energy rather than resisting conductive heat flow. A radiant barrier consists of a highly reflective aluminum foil surface that reflects up to 97 percent of the radiant heat that strikes it. When installed in attics, radiant barriers reduce the radiant heat transfer from the hot roof deck to the attic insulation below, effectively reducing the temperature of the attic space. Studies by the DOE show that radiant barriers can reduce cooling costs by 5 to 10 percent in hot, sunny climates (Zones 1-3). They are most effective when installed on the underside of roof rafters with the reflective side facing the attic space, and they must have an air space of at least three-quarters of an inch to function properly. Radiant barriers provide minimal benefit in cold climates where heating is the primary concern.
Radiant Barrier Specifications
Best Applications for Radiant Barrier
Radiant Barrier is recommended for the following building components. Each application link shows the specific R-value requirements by climate zone and how Radiant Barrier compares against other insulation options for that component.
Advantages and Limitations
Every insulation type has trade-offs that affect its suitability for different applications. Understanding these trade-offs helps you select the right insulation for your specific project requirements, budget, and installation constraints.
Advantages of Radiant Barrier
- Suitable for DIY installation, reducing labor costs
- Excellent moisture resistance for wet or below-grade applications
- Non-combustible — no thermal barrier required in most applications
- Well-suited for: Attic
Limitations of Radiant Barrier
- No R-value — reduces radiant heat gain only, minimal benefit in cold climates
Compare Other Insulation Types
Browse specifications and cost analysis for other insulation materials to find the best option for your project.