This specification identifies all types of heavy layer or sound barrier materials and their usage with sound absorbing or dissipative materials for noise decoupling assemblies.

Material Description. Products qualified to this specification shall be identified in two (2) parts. The first part shall identify heavy layer sound barriers by class according to density ranges. These heavy layer materials will be further identified, in 1.1.4 and 1.1.5 as decoupler assemblies and/or dash mats when used in conjunction with sound absorbing materials identified in GMW14194 and GMW14196.

Classification. All heavy layer sound barrier materials qualified to this specification shall be listed by class.

Class 1 - (2.5 kg/m² ± 0.50 kg/m²).

Class 2 - (3.5 kg/m² ± 0.50 kg/m²).

Class 3 - (4.5 kg/m² ± 0.50 kg/m²).

Class 4 - (5.5 kg/m² ± 0.50 kg/m²).

Class 5 - (Barrier materials < 2.0 kg/m² or > 6.0 kg/m²).

Mass per unit area for Class 5 barrier materials must be specified in math file and on print.

Some barrier materials may have densities which vary between two (2) classes. If this is the case, the material shall fall into the higher Class of material, (e.g, a material with density of 2.8 ± 0.3 shall be considered a Class 2 material).

All decoupler assemblies shall be identified by the proper class of heavy layer and the specific type of sound absorbing material as identified in GMW14194 or GMW14196.

Decoupler Identifications.

Fibrous Noise Decoupler Combinations. Material is designated by "A"; Type refers to only those fibrous materials outlined in GMW14194. Example designation: GMW14171 Class 2 Type A4.

Polyurethane Foam Noise Decoupler Combinations. "Material" is designated by "B"; Type refers to only those materials referenced in GMW14196.

Symbols. Not applicable.

Applicability. Dash mats and isolators.