CavityBoard - PowerWool

Why Use CavityBoard?

PowerWool CavityBoard™ – the premier choice for exterior cavity wall and rainscreen applications.

PowerWool™ CavityBoard™ is a semi-rigid mineral wool insulation board engineered for exterior cavity wall and rainscreen applications. Designed for high-performance building envelopes, CavityBoard™ provides long-term durability, fire safety, and moisture resilience.

Its consistent thermal performance and dimensional stability make it ideal for continuous insulation in ventilated and open-joint cladding systems. For added convenience and aesthetic integration.

Key Performance Benefits

Noncombustible and fire resistant
Compatible with NFPA 285 designs for multi-story assemblies
Water- and moisture-repellent
Vapor permeable to support wall drying
Durable, inorganic composition that does not promote mold, mildew, or decay
Dimensionally stable, maintaining performance over time

Why Choose Mineral Wool Insulation

Mineral wool insulation offers a combination of fire resistance, moisture management, and durability that makes it ideal for high-performance cavity wall systems:
Noncombustible, helping contain fire and prevent spread within the assembly
Vapor permeable and water-resistant, supporting effective drainage and drying in exterior walls
Inorganic and durable, it does not rot or support microbial growth

CHARACTERISTIC

RESULT

TEST STANDARD

Compliance

Mineral Fiber Block and Board Thermal Insulation – Compliant
Mineral Fiber Thermal Insulation for Buildings – Compliant

ASTM C612
CAN/ULC S702.1

Reaction to Fire

Flame spread index = 0; Smoke developed index = 0
Flame spread index = 0; Smoke developed index = 0
Determination of Non Combustibility of Building Materials – Non Combustible
Behaviour of materials at 750°C – Non Combustible

ASTM E84 (UL 723)
CAN/ULC S102
CAN/ULC S114
ASTM E136

Density

4.5 lbs/ft³ (72kg/m³) – Actual

ASTM C303

Dimensional Stability

Linear Shrinkage = Pass @1200°F (650°C)

ASTM C356

Corrosion Resistance

Corrosion of Steel – Passed

ASTM C665

Thermal Resistance

R-Value / inch @ 75°F — 4.2 hr.ft².F/Btu
RSI value / 25.4 mm @ 24°C — 0.74 m²K/W

ASTM C518

Reaction to Moisture

Moisture Sorption – Pass
Water Vapor Transmission, Desiccant Method – 1670ng/Pa.s.m² (29 perm)
Determination of Fungi Resistance – Passed

ASTM C1104
ASTM E96
ASTM C1338

Dimensions

1½” (38 mm) to 6″ (152.4 mm) in ½” increments
16″ × 48″ (406 mm × 1219 mm)
24″ × 48″ (610 mm × 1219 mm)

Acoustic Performance

Thickness	125Hz	250Hz	500Hz	1000Hz	2000Hz	4000Hz	NRC	SAA
1.5″	0.09	0.47	0.97	1.04	0.99	0.98	0.85	0.88
2″	0.26	0.88	1.12	1.06	0.99	1.00	1.00	1.01
2.5″	0.39	1.06	1.15	1.06	1.02	1.07	1.05	1.06
3″	0.57	1.12	1.14	1.03	1.02	1.02	1.10	1.07
4″	0.76	1.13	1.09	1.03	1.01	1.04	1.05	1.06

ASTM C423-23
ASTM E795-23

Applications

PowerWool™ CavityBoard™ is engineered for versatility in commercial, industrial, and multi-story residential construction, including:

Exterior continuous insulation for above-grade walls
Exterior cavity walls, rainscreens, and ventilated facades
Open-joint and clip-mounted cladding systems
Integration with pre-engineered attachment systems such as clips, rails, continuous girts, and masonry ties

From cavity wall assemblies to ventilated facades, PowerWool™ CavityBoard™ delivers a durable, fire-safe, and moisture-resilient solution that simplifies installation while maintaining long-term thermal and acoustic performance.

Sizes Available: All boards are 24″x48″ in size ranging in thickness from 1″ to 8″ thick