Acoustical Smooth Board

Acoustical Smooth Board

Knauf Insulation Acoustical Smooth Board is a thermal and acoustical insulation product made from inorganic glass mineral wool pre-formed into boards and bonded by a thermosetting resin.


Knauf Insulation Acoustical Smooth Board is a versatile product fitting for a variety of thermal and acoustical applications such as office partitions, interior panels, and sound baffles.

Features and Benefits

Density and Size Availability

• Knauf Insulation Acoustical Smooth Board is available in the densities and sizes required by panel and ceiling manufacturers. Special items not shown on the price and data sheet can be made based on our process capability.

Surface Smoothness

• The top surface is smooth which allows for flatness and uniformity.

Precision Tolerances

• Tolerances are +/- 1/16" (1.59 mm) for thickness and +/- 1/8" (3.18 mm) for width and length


• The board is suitable for machining.

Noise Reduction

• Excellent sound absorption characteristics, an important benefit for today’s office and interiors


• Available on pallets and in cartons  (See Packaging table)

Specification Compliance

In U.S.:

• ASTM C 612; Type IA and Type IB

• California Title 24

• HH-I-558C

— Form A, Class 1 and Class 2

• NFPA 90A and 90B

In Canada:

• CAN/ULC S102-M88

• CGSB 51-GP-10M

Technical Data

Surface Burning Characteristics

(UL Classified)

• Does not exceed 25 Flame Spread, 50 Smoke Developed when tested in accordance with ASTM E 84, CAN/ULC S102-M88, NFPA 90A and 90B, NFPA 255 and UL 723

Temperature Range (ASTM C 411)

• Operating temperatures from 0°F to 450°F (-18°C to 232°C)

Corrosiveness (ASTM C 665)

• Will not accelerate corrosion of aluminum, steel or copper

Shrinkage (ASTM C 356)

• Less than 0.3% linear shrinkage

Mold Growth (ASTM C 1338)

• Does not promote growth

Water Vapor Sorption (ASTM C 1104)

• Less than 5% by weight

Odor (ASTM C 1304)

• Not objectionable

Product Availability

  1. Stock items are listed. The remainder of the product line is made-to-order.
  2. Acoustical Smooth Board is skidded smooth on one side except for 1/2" thick which is bisected as noted below.
  3. Product tolerances:+/- 1/16" (1.59 mm) thickness; +/- 1/8" (3.18 mm) width and length
  4. It is recommended that Acoustical Smooth Board be sampled and evaluated prior to ordering.
  5. For requirements not listed, contact your Knauf Insulation sales representative.

Glass Mineral Wool and Mold

Glass mineral wool insulation will not sustain mold growth. However, mold can grow on almost any material when it becomes wet and contaminated with organic materials. Carefully inspect any insulation that has been exposed to water. If it shows any sign of mold, it must be discarded. If the material is wet but shows no evidence of mold, it should be dried rapidly and thoroughly. If it shows signs of facing degradation from wetting, it should be replaced. Air handling insulation used in the air stream must be discarded if exposed to water.


The chemical and physical properties of Knauf Acoustical Smooth Board represent typical average values determined in accordance with accepted test methods. The data is subject to normal manufacturing variations. The data is supplied as a technical service and is subject to change without notice. References to numerical flame spread ratings are not intended to reflect hazards presented by these or any other materials under actual fire conditions.

Check with your Knauf Insulation sales representative to assure information is current.

Sound Absorption Coefficients

Forms Available