Copyright 2018 American Wood Council 1

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1 for Wood Frame Assemblies BCD800 Jason Smart, P.E. Manager, Engineering Technology American Wood Council The American Wood Council is a Registered Provider with The American Institute of Architects Continuing Education Systems (AIA/CES), Provider # Credit(s) earned on completion of this course will be reported to AIA CES for AIA members. Certificates of Completion for both AIA members and non-aia members are available upon request. Participants may download the presentation here: resources This course is registered with AIA CES for continuing professional education. As such, it does not include content that may be deemed or construed to be an approval or endorsement by the AIA of any material of construction or any method or manner of handling, using, distributing, or dealing in any material or product. Questions related to specific materials, methods, and services will be addressed at the conclusion of this presentation. 2 1

2 COURSE DESCRIPTION Building codes stipulate minimum performance requirements regarding noise transmission through common interior walls and floor/ceiling assemblies that separate a dwelling unit from either a public area or an adjacent dwelling unit. Compliance with these requirements may be demonstrated either through testing or through engineering analysis based on empirical test data from other similar assemblies. This presentation provides an overview of an empirical model which may be used for analysis of wood-frame floor/ceiling assemblies to estimate the coderegulated sound transmission parameters. 3 POLLING QUESTION 1. What is your profession? a) Architect b) Engineer c) Building Code Official d) Fire Service e) Other 4 2

3 LEARNING OBJECTIVES Sound Transmission Basics 1 3 Learn about the basic physics of sound transmission through and around floor/ceiling or wall assemblies in a building, and how this is perceived by occupants within the building. 2 Code Requirements 4 Understand the code provisions relating to sound transmission, and how compliance with these code provisions may be demonstrated. Model Development Describe the scope of the AWC empirical sound transmission model, how it was developed, how it works, and how it was validated. Model Application Evaluate how the model can be used to estimate sound transmission parameters in order to demonstrate code compliance. Understand the scope and limitations of the model. 5 Outline Sound Transmission in Buildings Code Requirements Sound Transmission Data and Analysis Description of TR15 Model Model Accuracy and Validation Example Model Applications 6 3

4 SOUND TRANSMISSION IN BUILDINGS Sound is transmitted through a building in multiple ways Between spaces separated by walls or floor/ceiling assemblies: Sound transmission through an assembly Flanking around an assembly 7 SOUND TRANSMISSION IN BUILDINGS Sound Transmission Through an Assembly Airborne sound transmission Structure-borne sound transmission 8 4

5 SOUND TRANSMISSION IN BUILDINGS Airborne sound transmission - Amplified electronic devices - Human voices or pets - Musical instruments Laboratory test: ASTM E90 Measured parameter: Transmission Loss (TL) Single-number rating: Sound Transmission Class (STC) 9 SOUND TRANSMISSION IN BUILDINGS Structure-borne sound transmission - Footfall (stomping) noise - Objects dropped on floor Laboratory test: ASTM E492 Measured parameter: Impact Sound Pressure Level (ISPL) Single-number rating: Impact Insulation Class (IIC) 5

6 SOUND TRANSMISSION IN BUILDINGS Mass Law for Sound Transmission Through a Solid Panel Sound Transmission Loss (db) R = Log (fm) - 47 (Slope: 6 db per octave) 0 1,000,000 0,000 1,000,000 fm (Hz kg/m 2 ) 11 Outline Sound Transmission in Buildings Code Requirements Sound Transmission Data and Analysis Description of TR15 Model Model Accuracy and Validation Example Model Applications 12 6

7 BUILDING CODE REQUIREMENTS IBC provisions address both airborne and structureborne sound transmission Applicable to assemblies separating: - Dwelling or sleeping spaces from each other - Dwelling or sleeping spaces from a public area 13 BUILDING CODE REQUIREMENTS Airborne Sound Transmission Provisions 14 7

8 BUILDING CODE REQUIREMENTS Structure-borne Sound Transmission Provisions 15 BUILDING CODE REQUIREMENTS Summary of Applicable Test Standards and Code Provisions 16 8

9 POLLING QUESTION 2. What way(s) can the code required minimum STC and IIC ratings be demonstrated for an assembly? a) Ongoing full scale structural monitoring b) Direct laboratory testing per ASTM E90 and E492 c) Engineering analysis based on comparison to other E90 tests. d) Either b) or c) 17 Outline Sound Transmission in Buildings Code Requirements Sound Transmission Data and Analysis Description of TR15 Model Model Accuracy and Validation Example Model Applications 18 9

10 SOUND TRANSMISSION DATA AND ANALYSIS Compiling the modeling database: Initially compiled more than 300 STC and IIC data points from 17 different sources Database was subsequently pared to include only assemblies with: - Sawn lumber, I-joist or wood truss framing - Resilient channels (at various spacings) - Gypsum wallboard ceiling 19 SOUND TRANSMISSION DATA AND ANALYSIS Research/testing showed significant inter-laboratory differences Confounding factor in data comparisons Database must consist of data from single laboratory source Majority of usable data was from NRC

11 SOUND TRANSMISSION DATA AND ANALYSIS Available NRC data robust for untopped assemblies without floor coverings AWC performed additional ASTM E90 and E492 tests at NRC on 31 assemblies not addressed in the NRC data, including: - Gypsum concrete-topped assemblies - Assemblies with I-joists at 24 & RCs at 16 - Assemblies having various floor coverings - Other configurations to improve database 21 SOUND TRANSMISSION DATA AND ANALYSIS AWC Modeling database included: - 48 complete bare-floor assemblies - 14 assemblies having various floor coverings - 16 partial assemblies (ceiling-only or floor-only) Validation database: - 35 bare-floor assemblies - 4 assemblies having floor coverings Test data from 117 assemblies in all 22 11

12 SOUND TRANSMISSION DATA AND ANALYSIS Component Topping Tested Ranges Material Type Minimum Maximum NRC Reference Case ~1 nominal thickness (± Gypsum Concrete 1 / 8 ) psf 11 psf (None) layer OSB 19 / / / 32 Subfloor Insulation 2-layer OSB (2 layers 19 / 32 ) -- 1-layer Plywood 19 / layer Plywood (2 layers 1 / 2 ) (2 layers 19 / 32 ) -- Fiberglass 2 1 / 2 thick 8 thick Batt 0.7 pcf ±0.1 pcf 0.7 pcf ±0.1 pcf 6 thick Mineral Wool Batt 3 1 / 2 thick 8.3 thick 2 pcf ±0.5 pcf 2 pcf ±0.5 pcf -- (None) Sawn Lumber 2x8 2x12 2x Framing Wood I-joist 9.5 deep 18 deep -- Wood Truss 14 deep 18 deep -- Framing Spacing (any of the above) 16 o.c. or 24 o.c. 16 o.c. 13mm-deep, 25 gage, 13mm-deep, 25 gage, Metal Furring RC1 Resilient Channels spaced 16 or 24 o.c. spaced 24 o.c. 1-layer GWB psf ±0.2 psf psf ±0.2 psf 5 / 8 thick Type X 1 / thick Type C 5 / thick Type X Ceiling Membrane 1-layer Lightweight GWB psf ±0.2 psf 1 / thick Type -- 2-layer GWB (2 layers 1 / 2 ) Type C (2 layers 5 / 8 ) Type X 3.6 psf ±0.4 psf 4.4 psf ±0.4 psf -- 2-layer Lightweight GWB (2 layers 1 / 2 ) Type 3 psf ±0.3 psf SOUND TRANSMISSION DATA AND ANALYSIS Component Combinations Represented Within Database (Assemblies Without Topping). Grey cells: within modeling database Green cells: within validation database Ceiling Membrane 1 lyr 1 /2" lt.wt. GWB 1 layer 1 /2" GWB 1 layer 5 /8" GWB 2 lyr 1 /2" lt.wt. GWB 2 layer 1 /2" GWB 2 layer 5 /8" GWB Furring 24" o.c. 16" o.c. 16" o.c. 16" o.c. 24" o.c. 16" o.c. 9.5" 16" o.c. Framing 9.5" 24" o.c. 14" o.c. 18" o.c. 12" 16" o.c. 14" 16" o.c. 14" 24" o.c. 18" 24" o.c. 24" 24" o.c. 2.6" Fiberglass Batt 3.5" Fiberglass Batt Insulation 6" Fiberglass Batt 8" Fiberglass Batt 3.5" Min. Wool Batt 8.3" Min. Wool Batt (None) 1 layer 19 /32" OSB 1 layer 23 /32" OSB 2 layer 19 /32" OSB Subfloor 1 layer 19 /32" Plywood 1 layer 1" Plywood 2 layer 1 /2" Plywood 2 layer 19 /32" Plywood 2.6" Fiberglass Batt 3.5" Fiberglass Batt 6" Fiberglass Batt Insulation 8" Fiberglass Batt 3.5" Mineral Wool Batt 8.3" Mineral Wool Batt (None) 16" o.c. 16" o.c. 24" o.c. 16" o.c. 9.5" Wood I o.c. 9.5" Wood I 24" o.c. Framing 14" Wood I 16" o.c. 18" Wood I 16" o.c. 12" Wood 16" o.c. 14" Wood 16" o.c. 14" Wood 24" o.c. 18" Wood 24" o.c. 24" Wood 24" o.c. 24" o.c. Furring 16" o.c

13 SOUND TRANSMISSION DATA AND ANALYSIS Component Combinations Represented Within Database (Assemblies With 1" GC Topping). Grey cells: within modeling database Green cells: within validation database Ceiling Membrane 1 lyr 1 /2" lt.wt. GWB 1 layer 1 /2" GWB 1 layer 5 /8" GWB 2 lyr 1 /2" lt.wt. GWB 2 layer 1 /2" GWB 2 layer 5 /8" GWB Furring Framing Insulation 24" o.c. 16" o.c. 16" o.c. 16" o.c. 24" o.c. 16" o.c. 9.5" 16" o.c. 9.5" 24" o.c. 14" o.c. 18" o.c. 12" 16" o.c. 14" 16" o.c. 14" 24" o.c. 18" 24" o.c. 24" 24" o.c. 2.6" Fiberglass Batt 3.5" Fiberglass Batt 6" Fiberglass Batt 8" Fiberglass Batt 3.5" Min. Wool Batt 8.3" Min. Wool Batt (None) 1 layer 19 /32" OSB 1 layer 23 /32" OSB 2 layer 19 /32" OSB Subfloor 1 layer 19 /32" Plywood 1 layer 1" Plywood 2 layer 1 /2" Plywood 2 layer 19 /32" Plywood 2.6" Fiberglass Batt 3.5" Fiberglass Batt 6" Fiberglass Batt Insulation 8" Fiberglass Batt 3.5" Mineral Wool Batt 8.3" Mineral Wool Batt (None) 16" o.c. 16" o.c. 24" o.c. 16" o.c. 9.5" Wood I o.c. 9.5" Wood I 24" o.c. Framing 14" Wood I 16" o.c. 18" Wood I 16" o.c. 12" Wood 16" o.c. 14" Wood 16" o.c. 14" Wood 24" o.c. 18" Wood 24" o.c. 24" Wood 24" o.c. 24" o.c. Furring 16" o.c. 25 SOUND TRANSMISSION DATA AND ANALYSIS Measured TL and STC Contour for Reference Assembly Transmission Loss, db STC for Reference Assembly: 52 Measured TL ASTM E413 Contour Frequency, Hz 26 13

14 SOUND TRANSMISSION DATA AND ANALYSIS Measured ISPL and IIC Contour for Reference Assembly 80 Impact Sound Pressure Level, db IIC for Reference Assembly: 46 Measured ISPL ASTM E989 Contour Frequency, Hz 27 SOUND TRANSMISSION DATA AND ANALYSIS Transmission Loss of Individual Layers 60 Transmission Loss (db) Frequency (Hz) Floor Layer Mass Law 19/32" OSB and 2xs Transmission Loss (db) Ceiling Layer Mass Law 1 Layer 5/8" GWB and 2xs Frequency (Hz)

15 SOUND TRANSMISSION DATA AND ANALYSIS Assembly TL Values vs. Sum of Layer TL Values 0 90 Transmission Loss (db) Frequency (Hz) Sum of Layer TL Values Reference Assembly Difference in Transmission Loss (db) Difference: System Effect Frequency (Hz) System Effect: Reference Assembly 29 SOUND TRANSMISSION DATA AND ANALYSIS System Effects: Various Insulation Types/Thicknesses Difference in Transmission Loss (db) Frequency (Hz) 8.3" Mineral Wool 3.5" Mineral Wool 8" Fiberglass 6" Fiberglass 3.5" Fiberglass 2.5" Fiberglass No Insulation 30 15

16 SOUND TRANSMISSION DATA AND ANALYSIS System Effects: Various Ceiling Layers Difference in Transmission Loss (db) Frequency (Hz) 1 Layer 5/8" GWB 2 Layers 5/8" GWB 1 Layer 1/2" GWB 2 Layers 1/2" GWB 1 Layer 1/2" Lt.Wt. GWB 2 Layers 1/2" Lt.Wt. GWB 31 SOUND TRANSMISSION DATA AND ANALYSIS System Effects: Various Floor Layers Difference in Transmission Loss (db) Frequency (Hz) 1 Layer 19/32" OSB 2 Layers 19/32" OSB 1 Layer 19/32" Plywood 1 Layer 1" Plywood 2 Layers 1/2" Plywood 2 Layers 19/32" Plywood 32 16

17 POLLING QUESTION 3. Data from over 0 tested assemblies was used to develop and validate the TR15 model. True or False 33 Outline Sound Transmission in Buildings Code Requirements Sound Transmission Data and Analysis Description of TR15 Model Model Accuracy and Validation Example Model Applications 34 17

18 DESCRIPTION OF TR15 MODEL TR15 Model Overview (STC) 35 DESCRIPTION OF TR15 MODEL Excerpt from TR15: TL l Values for the Floor Layer 36 18

19 DESCRIPTION OF TR15 MODEL Excerpt from TR15: TL l Values for the Ceiling Layer 37 DESCRIPTION OF TR15 MODEL TR15 Baseline Assemblies 38 19

20 DESCRIPTION OF TR15 MODEL Excerpt from TR15: System Effects and Adjustments 39 DESCRIPTION OF TR15 MODEL STC Model Estimated TL a is evaluated at each 1 / 3 -octave frequency Reference Contour is fitted to the estimated TL contour per ASTM E413, such that: - Sum of deficiencies across all frequencies does not exceed 32 db - Single-point deficiency does not exceed 8 db frequency Deficiency: Difference between TL a and the shifted reference contour, counted only where negative 40

21 DESCRIPTION OF TR15 MODEL 41 DESCRIPTION OF TR15 MODEL TR15 Model Overview (IIC) 42 21

22 DESCRIPTION OF TR15 MODEL Excerpt from TR15: ISPL Adjustment Values 43 DESCRIPTION OF MODEL IIC Model Estimated ISPL a is evaluated at each 1 / 3 -octave frequency Reference Contour is fitted to the estimated ISPL contour per ASTM E989, such that: - Sum of deficiencies across all frequencies does not exceed 32 db - Single-point deficiency does not exceed 8 db frequency Deficiency: Difference between ISPL a and the shifted reference contour, counted only where positive 44 22

23 DESCRIPTION OF MODEL 45 POLLING QUESTION 4. Which of the following is not used within the TR15 STC model? a) Individual transmission losses of the ceiling & floor layers b) The noise reduction coefficient of the assembly c) The system effect of the baseline assembly d) Adjustments to account for variations from the baseline assembly 46 23

24 Outline Sound Transmission in Buildings Code Requirements Sound Transmission Data and Analysis Description of TR15 Model Model Accuracy and Validation Example Model Applications 47 MODEL ACCURACY AND VALIDATION Model-estimated values compared to measured values for the following assemblies: All complete assemblies from the modeling database: - 48 bare-floor assemblies (STC) - 14 assemblies having floor coverings (IIC) All other data available for model validation: - 35 bare-floor assemblies (STC model validation) - 4 other assemblies having floor coverings (IIC) 1 assemblies in total 48 24

25 MODEL ACCURACY AND VALIDATION 75 Measured vs. Modeled Values 70 Modeled Value (db) IIC Validation Data & Modeling Database 55 (n=18) STC Validation Data (n=26) STC Validation Data (Wood Trusses) (n=9) 45 STC Modeling Database (n=48) Measured Value (db) 49 MODEL ACCURACY AND VALIDATION Number of STC and IIC Data Points Underestimation Overestimation Modeling Database IIC Database & Validation Validation Data (Trusses) Validation Data (2x & I-joists) Difference Between Model Estimation and Measured Value 25

26 MODEL ACCURACY AND VALIDATION All model-estimated values were within ±3 STC/IIC points of the measured values - 83% of estimations within ±1 STC/IIC point of measured value Slight tendency to underestimate for assemblies having multiple component variations (conservative) Reasonably accurate for estimation of STC & IIC on assemblies within the model scope - Light-frame floor-ceiling assemblies having component combinations addressed in TR15 51 Outline Sound Transmission in Buildings Code Requirements Sound Transmission Data and Analysis Description of TR15 Model Model Accuracy and Validation Example Model Applications 52 26

27 EXAMPLE MODEL APPLICATIONS Example 1 (Untopped; 2x 16 o.c.): Thin carpet (0.24 thick, oz/yd 2 ) over a typical underpad (0.31 thick, 0. psf) One layer 19/32 OSB One layer 6 -thick fiberglass insulation batt between joists 2x joists at 16 o.c. RC1 resilient channels, spaced 24 o.c., running perpendicular to joists One layer 5/8 Type X gypsum wallboard 53 EXAMPLE MODEL APPLICATIONS Example 1 (Untopped; 2x 16 o.c.) Estimation of TL and STC: 54 27

28 EXAMPLE MODEL APPLICATIONS Example 1 (Untopped; 2x 16 o.c.) 0 90 Transmission Loss (db) Deficiencies Shifted Reference Contour Estimated TL Frequency (Hz) 55 EXAMPLE MODEL APPLICATIONS Example 1 (Untopped; 2x 16 o.c.) 0 Transmission Loss (db) Difference Measured TL (With Floor Covering) Estimated TL (Bare-floor Assembly) Frequency (Hz) 56 28

29 EXAMPLE MODEL APPLICATIONS Example 1 (Untopped; 2x 16 o.c.) Estimation of ISPL and IIC: 57 EXAMPLE MODEL APPLICATIONS Example 1 (Untopped; 2x 16 o.c.) 0 Impact Sound Pressure Level (db) Deficiencies Shifted Reference Contour Estimated ISPL Frequency (Hz) 58 29

30 EXAMPLE MODEL APPLICATIONS Example 1 (Untopped; 2x 16 o.c.) STC - Estimated: 52 (based on bare-floor model) - Measured: 53 (tested with carpet and pad) IIC - Estimated: 66 - Measured: EXAMPLE MODEL APPLICATIONS Example 2 (Topped assembly; I-joist 24 o.c.): Floating wood laminate flooring (0.31 thick, 1.35 psf) over a thin closed-cell foam underlay (0.06 thick, negligible weight) Nominal 1 gypsum concrete topping One layer 23/32 OSB One layer 6 -thick fiberglass insulation batt between the joists 9.5 -deep prefabricated wood I-joists at 24 o.c. RC1 resilient channels, spaced 16 o.c., running perpendicular to joists Two layers 5/8 Type X gypsum wallboard 60 30

31 EXAMPLE MODEL APPLICATIONS Example 2 (Topped assembly; I-joist 24 o.c.) Estimation of TL and STC: 61 EXAMPLE MODEL APPLICATIONS Example 2 (Topped assembly; I-joist 24 o.c.) 0 Transmission Loss (db) Difference Measured TL (With Floor Covering) Estimated TL (Bare-floor Assembly) Frequency (Hz)

32 EXAMPLE MODEL APPLICATIONS Example 2 (Topped assembly; I-joist 24 o.c.) Estimation of ISPL and IIC: 63 EXAMPLE MODEL APPLICATIONS Example 2 (Topped assembly; I-joist 24 o.c.) STC - Estimated: 67 (based on bare-floor model) - Measured: 67 (tested with carpet and pad) IIC - Estimated: 56 - Measured: 56 (test data used to derive ISPL adjustments) 64 32

33 POLLING QUESTION 5. The TR15 model is used for estimation of for light frame floor ceiling assemblies? a) STC and IIC ratings b) Sound absorption c) Reverberation times d) All of the above 65 This concludes the American Institute of Architects Continuing Education Systems Course This presentation is protected by US and International Copyright laws. Reproduction, distribution, display and use of the presentation without written permission of American Wood Council (AWC) is prohibited. American Wood Council 18 33