Unfaced Insulation: Definition and What it is

What is Unfaced Insulation?

Unfaced insulation has no attached vapor retarder or facing material—it's pure insulation material without any additional layers. It's used when a vapor barrier isn't needed, when using a separate vapor barrier, or when adding insulation over existing faced insulation.

Unfaced batts and rolls are the preferred choice for interior walls where no vapor control is needed, for second layers of attic insulation, and in climates where vapor barriers aren't required. Without facing, the insulation is slightly less expensive and allows vapor permeability in assemblies where that's desirable. Unfaced insulation friction-fits between framing members or can be held with wire supports, staples, or netting. It's essential for layering over existing faced insulation—doubling up vapor barriers traps moisture.

Common Unfaced Insulation Uses

• Interior Walls: Sound control between rooms, no moisture control needed
• Attic Top-offs: Adding to existing insulation without creating double vapor barrier
• With Separate Vapor Barrier: When installing poly sheeting or other independent vapor barrier
• Mild Climates: Zones where vapor barriers aren't code-required

When to Choose Unfaced Insulation

Use unfaced insulation for interior partition walls to improve soundproofing without moisture concerns. Always use unfaced when adding a second layer over existing faced insulation. If your climate or building code requires vapor barriers, install unfaced insulation with separate polyethylene sheeting. In hot-humid climates, unfaced insulation often performs better than faced products. When installing unfaced batts, cut to fit snugly without compression. Use supports, friction-fit properties, or light stapling to hold insulation in place until drywall installation.

Benefits of Unfaced Insulation

• Less expensive than faced insulation
• Allows vapor permeability when needed
• Ideal for interior walls and sound control
• Can be layered over existing faced insulation
• Eliminates risk of double vapor barriers
• Suitable for climates not requiring vapor barriers

Unfaced Insulation Cost

Unfaced insulation costs slightly less than faced versions and is often preferred for specific applications.

• Material cost ($0.05-$0.15/sq ft less than faced)
• R-value and thickness requirements
• Material type (fiberglass, mineral wool, etc.)
• DIY installation vs. professional labor
• Support materials if needed (wire, netting)
• Separate vapor barrier costs if required

Related Services and Resources

Related Terms

• Faced Insulation: Definition and What it is
• Batt & Roll Insulation: Definition and What it is
• Fiberglass (Glass Fiber) Insulation: Definition and What it is
• Vapor Barrier Insulation: Definition and What it is

References

• Wikipedia - Thermal Insulation
• Energy.gov - Insulation (Energy Saver)
• National Insulation Association - Insulation Basics
• ICAA - Insulation for Consumers