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SoundBreak® XP® Installation Guidlines


Applicable Standards and References

  • ASTM C 840
  • Gypsum Association GA-216
  • Gypsum Association GA-214
  • National Gypsum – Gypsum Construction Guide


Installation of SoundBreak XP Gypsum Board should be consistent with methods described in the standards and references noted.

Guidelines for Optimum Performance and Sound Reduction

  • Stagger SoundBreak XP Gypsum Board joints from one side of the wall to the other
  • Allow a 1/″ gap along all wall perimeter edges and completely seal 1/4″ gap with acoustical sealant or caulk.
  • Refrain from wall penetrations when possible.
  • Limit necessary wall penetrations to one per stud cavity.
  • Seal all penetrations with acoustical sealant and/or putty pads.
  • The use of SoundBreak XP Gypsum Board in actual installations may not produce the same results as were achieved in controlled, laboratory conditions.

Cutting Soundbreak XP Gypsum Board

  • Use a hand or electric saw. Cutting across the 4′ width may require use of a saw.

Acoustical Sealants and Putty Pads

  • Use an acoustical sealant that is applied per ASTM C919, such as AcoustiSeal or equivalent.
  • Use a putty pad that has been tested per ASTM E90.


For best painting results, all surfaces, including joint compound, should be clean, dust-free and not glossy. To improve fastener and joint concealment, a coat of quality drywall primer is recommended to equalize the porosities between surface paper and joint compound.

The selection of a paint to give the specified or desired finished characteristics is the responsibility of the architect or contractor.

SoundBreak XP Gypsum Board that is to have a wall covering applied should be prepared and primed as described for painting.

Gypsum Association GA-214, Recommended Specification for Levels of Gypsum Board Finish, should be referred to in order to determine the level of finishing required to ensure a properly prepared surface that accepts the desired decoration.

Technical Data

Fire Resistance Ratings

Fire resistance ratings represent the results of tests on assemblies in a specific configuration. When selecting construction designs to meet certain fire resistance requirements, caution must be used to ensure that each component of the assembly is the one specified in the test. Further precautions should be taken that assembly procedures are in accordance with those of the tested assembly. For copies of specific tests, call 1-800-NATIONAL.

5/8″ SoundBreak XP can be used as a substitute for Type X gypsum board in some proprietary fire-rated assemblies.

As an option, 1/2″ SoundBreak XP may be used as an additional layer on one or both sides of fire-rated wall assemblies. 1/2″ SoundBreak XP cannot be used as a substitute for 5/8″ Type X gypsum board in a fire-rated assembly.

SoundBreak XP shall be attached in accordance with manufacturer’s recommendations. When SoundBreak XP is installed between the framing and the UL Classified gypsum board, the UL Classified gypsum board layer(s) required for the design is/are to be installed as indicated in the design as to fastener type and spacing, except that the required fastener length shall be increased by a minimum of 5/8″.

Mold and Mildew Resistance*

SoundBreak XP Gypsum Board was designed to provide extra protection against mold and mildew compared to standard gypsum board products. When tested by an independent laboratory, SoundBreak XP received the highest possible ratings on ASTM G 21 and ASTM D 3273.

The use of SoundBreak XP in actual installations may not produce the same results as were achieved in controlled laboratory conditions.

*No material can be considered “mold-proof”, nor is it certain that any material will resist mold or mildew indefinitely. When used in conjunction with good design, handling, and construction practices, SoundBreak XP Gypsum Board can provide increased mold resistance versus standard gypsum board products. As with any building material, avoiding water exposure during handling, storage and installation, and after installation is complete, is the best way to avoid the formation of mold or mildew.