176048 1 Cover

176048 1 dividers.pdf13/31/152:41 PM

These gypsum wallboard system details are intended solely as technical support incident to the sale and use ofNational Gypsum Company products. They may be used as a reference by architects, engineers, other designprofessionals, contractors, building code officials, or other competent construction industry trade personnelconsidering the selection, specification and use of National Gypsum Company products in these systems.Architects, engineers, designers or contractors involved should review these details with the governing code orinspection official at the time of the job submittal to determine if there are any discrepancies with local code orregulatory requirements. In any event, they must NOT be used without a complete evaluation by the owner'sdesign professional to verify the suitability of the system for a given application.These system details may be printed and/or transferred electronically as needed by the user, subject to termsand limitations of any applicable license agreement. Any unauthorized duplication or reuse of the materialcontained herein is a violation of law.These system performance details are the result of tests conducted in accordance with ASTM E90 undercontrolled laboratory conditions. Actual sound transmission loss of systems constructed in the field may varyfrom these performance details based upon many factors such as the actual field conditions, specificcomponents used, and installation methods.

Table of ContentsAcoustical Terms and Concepts1Steel Stud Partitions with Framing 16" o.c.5Partitions with Lightweight Gypsum BoardSteel Stud Partitions with Framing 24" o.c.Partitions with Lightweight Gypsum Board131925Steel Stud Chase Walls29Shaftwall Partitions33Wood Stud Partitions with Framing 16" o.c.41Partitions with Lightweight Gypsum Board47Wood Stud Partitions with Framing 24" o.c.51Wood Stud Chase Walls57Area Separation Fire Walls61Floor-Ceiling Assemblies67Ceiling Attenuation Class of Gridstone Ceiling Assemblies71

Acoustical Terms and ConceptsTransmission of Airborne SoundSound Transmission ClassAirborne sound is acoustical energy generated by a source andtransmitted by vibration through the air. The vibrations createsound pressure fluctuations that are detected by a receiver.Sound is characterized by its frequency, which determines thepitch of the sound, and by the intensity of the pressurefluctuations, which determines how loud the sound is perceived tobe.The Sound Transmission Class (STC) is a single number rating ofthe effectiveness of a material or construction assembly to retardthe transmission of airborne sound. The STC provides anindication of how loud transmitted sound is perceived to be by thelistener. Partitions with higher STC values are more effective atreducing sound transmission.Sound TransmissionEnergy Generatedby a SourceTransmittedThrough a MediumDetected bya ReceiverDrumstick strikesdrumhead creatingvibrationsVibrationstransmitted throughthe air as pressurefluctuationsEar receivespressure fluctuationsand perceives themas soundThe frequency of sound refers to the number of sound pressurefluctuations or cycles that occur at a fixed point in one second.The unit of measure for frequency is the hertz (Hz), which is onecycle per second. The human auditory system is capable ofdetecting sound frequencies between 20 Hz and 20,000 Hz, buthumans are typically most sensitive to sounds within the range of500 Hz and 4,000 Hz. Sound frequency is perceived by humansas pitch. The lowest note on a piano has a frequency of 27.5 Hz,while the highest note on the piano is 4,186 Hz.The intensity of sound, or loudness, is measured in decibels (dB).A quiet whisper might register at 20 dB, compared to about 60 dBfor normal conversation, and 75 dB for loud singing. The decibelscale is logarithmic, not linear. A sound level change of 1 to 2 dBwill be difficult to perceive while a change of 5 dB will be clearlynoticeable. Sound is perceived to double in intensity for every 10dB increase and quadruple for every 20 dB increase.Human Sensitivity to Changes in Sound Intensity Levels1 dB3 dB5 dB10 dB20 dBGenerally not perceptibleJust perceptibleClearly noticeableTwice as loudFour times as loudRatingActivityPainfulVery LoudLoudModerateQuietVery QuietJet Engine .120 Industrial Machinery .100Stock Trading Floor . 80Normal Speech . 65Suburban Home . 45Barely Audible . 25Sound Level (dB)STC values are derived by conducting a test in accordance withASTM E90, Standard Method for Laboratory Measurement ofAirborne Sound Transmission Loss of Building Partitions. Thetest data collected is analyzed using ASTM E413, Classificationfor Rating Sound Insulation, and results in a single-numberacoustical rating. The rating assesses the airborne soundtransmission performance at a range of frequencies from 125 Hzto 4000 Hz, which is consistent with the frequency range of thehuman ear. An STC rating of 50 has been designated as theminimum allowable design rating for unit-to-unit multifamilyconstruction in the International Building Code.Design Considerations for Acoustical PartitionsThe goal of a high STC ratedpartition is to decrease theamount of sound transmissionthrough the partition.Thefollowing five variables canhave an impact on the abilityof the partition to retard thesound transmission.MassIncreasing the mass of apartition increases the amountof material airborne soundwaves must penetrate toreach the adjoining room andcan be accomplished byinstalling multiple layers ofgypsum board.StiffnessDecreasing the stiffness of apartition will increase theamount of sound transmissionloss. For this reason metalstuds outperform wood studs,and framing that is 24" o.c.outperforms framing that is 16"o.c.DampingDamping, or the ability todissipatethevibrationalenergy produced by soundwaves, reduces the amount ofenergy to pass through thepartition.Cavity DepthIncreasing the depth of thecavity of the partition canincrease the amount of soundtransmission loss, especiallywhen the cavity is filled withacoustical insulation.Cavity AbsorptionIncreasing the thickness ofsound-absorbing material suchas fiberglass or mineral fiberinsulation in the cavity of apartition will increase theamount of sound transmissionloss. The thickness of theinsulation has a greater effecton sound transmission lossthan the density.1

Acoustical Terms and ConceptsGuidelines for Optimum Performance and Sound ReductionSound Isolation ConstructionStagger gypsum board joints from one side of the partition tothe other.Allow a 1/4" gap along all wall perimeter edges andcompletely seal 1/4" gap with acoustical sealant.Refrain from wall penetrations when possible.Limit necessary wall penetrations to one per stud cavity.Arrows denote flanking paths for sound.Seal all penetrations with acoustical sealant or putty pads.Electrical boxes offset one stud cavity and annular spaces sealed.A new approach in noise reduction is represented by a new kindof acoustically enhanced gypsum board introduced by NationalGypsum. Gold Bond BRAND SoundBreak XP Gypsum Boardincorporates a sound-damping viscoelastic polymer sandwichedbetween two layers of high-density gypsum board. The polymerabsorbs and dissipates noise-producing vibrational energy byconverting it into negligible heat.SoundBreak XP gypsum board can be used alone or inconjunction with other sound reduction strategies for higher STCratings. As it can be installed and finished just like traditionalgypsum board, requiring no additional labor or materials, it can bea cost-effective solution for reducing sound transmission.5/8" SoundBreak XP gypsum board features a fire-resistant TypeX core and is UL classified. SoundBreak XP resists the growth ofmold when tested in accordance with ASTM D3273 with a scoreof 10, the best possible score. Heavy abrasion resistant paperand a denser core provide greater resistance to surface abuseand indentation when tested in accordance with ASTM C1629.SoundBreak XP gypsum board can be installed as the base layeror the face layer in multi-layer systems without affecting the STC.Arrows denote flanking paths for sound.Perimeter of partition sealed.Arrows denote flanking pathsfor sound.2Flutes of metal deck insulatedand sealed.

176048 1 dividers.pdf23/31/152:41 PM

176048 1 dividers.pdf33/31/152:41 PM

176048 1 dividers.pdf43/31/152:41 PM

176048 1 dividers.pdf53/31/152:41 PM

176048 1 dividers.pdf63/31/152:41 PM

176048 1 dividers.pdf73/31/152:41 PM

176048 1 dividers.pdf83/31/152:41 PM

176048 1 dividers.pdf93/31/152:41 PM

176048 1 dividers.pdf103/31/152:41 PM

176048 1 dividers.pdf113/31/152:41 PM

Ceiling Attenuation Class for Gridstone Ceiling AssembliesFigure 72Figure 72SoundSourceCAC-41SoundSourceNGC 6000001CAC-46NGC 6098001Ceiling:Suspended Grid with 2' x 4' x 5/16" GridstoneHi-Strength Ceiling PanelsInsulation: NoneCeiling:Suspended Grid with 2' x4' x 1/2" GridstoneCeiling PanelsInsulation: NoneFigure 72Figure 72SoundSourceCAC-44Ceiling:SoundSourceNGC 6013012Suspended Grid with 2' x 2' x 1/2" GridstoneCeiling PanelsInsulation: NoneCAC-51NGC 6013013Ceiling:Suspended Grid with 2' x 2' x 1/2" GridstoneCeiling PanelsInsulation: 3 1/2" glass fiber 48" on each side of partition71

Ceiling Attenuation Class for Gridstone Ceiling AssembliesFigure 72SoundSourceCAC-53Ceiling:NGC 6013014Suspended Grid with 2' x 2' x 1/2" GridstoneCeiling PanelsInsulation: 3-1/2" glass fiber full coverage over ceiling72

111268 11/15

Ceiling Attenuation Class for Gridstone Ceiling Assemblies CAC-51 NGC 6013013 Suspended Grid with 2' x 2' x 1/2" Gridstone Ceiling Panels 3 1/2" glass fiber 48" on each side of partition Ceiling: Insulation: Sound Source CAC-41 NGC 6000001 Suspended Grid with 2' x 4' x 5/16" Gridstone Hi-Strength Ceiling Panels