ROCKWOOL Comfortbatt® for Attic & Cathedral Ceiling Insulation

Product Overview:

Maximize your home's energy efficiency and comfort where it matters most—at the top. ROCKWOOL Comfortbatt® is an ideal solution for insulating attics and the sloped rafters of cathedral ceilings. Its high R-value per inch and dimensional stability ensure long-term thermal performance without settling, a common issue in attic spaces. By creating a robust thermal envelope at the roofline, it prevents costly heat loss in winter and heat gain in summer.

• Material: Dense, Semi-Rigid Stone Wool
• R-Value: R22 (for 5.5" thickness)
• Thickness: 5.5 inches (140mm)
• Dimensions: 15.25" x 47"
• Coverage per Bag: 39.8 sq. ft.
• Key Property: Non-settling, Dimensionally Stable

Superior Attic & Cathedral Ceiling Performance:

1. Prevents Thermal Bypass: The snug friction-fit and rigid structure ensure batts remain in place, fully filling rafter or joist cavities without gaps that create thermal shortcuts, a critical factor in complex ceiling geometries.
2. High-Temperature Stability: Unlike some plastics, stone wool retains its form and performance in extreme attic temperatures, which can soar in summer. It will not melt, degrade, or off-gas.
3. Enhanced Fire Protection at the Roofline: Provides a critical layer of non-combustible insulation directly under the roof decking, potentially slowing fire spread and providing added escape time—a key safety benefit.
4. Ideal for Ventilated Assemblies: Its excellent moisture resistance allows it to perform reliably in vented attic and roof assemblies, where condensation risk exists, without losing effectiveness.
5. Contributes to a Tight Building Envelope: When properly installed in cathedral ceilings (often using a "double-batt" technique for higher R-values), it is a key component in achieving high-performance, energy-efficient home standards.

Installation Considerations:

• For Attics (Floors): Place batts between ceiling joists with the vapor retarder facing down toward the conditioned living space.
• For Cathedral Ceilings (Rafters): Install batts between roof rafters, ensuring a minimum 1-inch air gap between the insulation and roof sheathing for proper ventilation. May require baffles to maintain this airflow channel.
• Always follow local building codes and manufacturer guidelines for required R-values in your climate zone.

Applications:

• Attic floor insulation (over flat ceilings)
• Knee wall insulation in finished attics
• Insulation for cathedral ceilings and sloped roofs
• Insulating skylight shafts