Wall and Knee Wall Installation

Radiant barrier can be used in wall and knee-wall applications when the assembly includes an air space. Product choice depends on whether the wall should breathe or act as a vapor barrier.

Ra-flect radiant barrier installed between studs in a knee-wall assembly
Knee-wall installation with insulation and a reflective air space.
Product choice: Use Laser Perforated (LP) for breathable assemblies. Use Vapor Barrier (VB) only when a non-perforated vapor barrier is intentional.

Wall approach

  1. Staple material to exterior sheathing or framing as designed.
  2. Maintain an air space, often with furring strips.
  3. Tape seams and penetrations where an air barrier is desired.
  4. Coordinate vapor-control decisions with local code and wall design.

Knee wall approach

Staple material inside wall studs while leaving space to the exterior sheathing. Overlap seams by about 2 inches and install insulation without compressing the air space.

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For walls, floors, and crawl spaces, product choice depends on the vapor-control strategy. Use Laser Perforated (LP) for a breathable assembly and Vapor Barrier (VB) only when a non-perforated vapor or radon barrier is intentional.

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