Acoustical Solutions Noise & Control in Wood Framed, Residential Structures

By Scott Harvey, PE, INCE Bd. Cert. Phoenix Noise & Vibration Frederick, Maryland •Copyright Materials • This presentation is protected by US and International Copyright laws. Reproduction, distribution, display and use of the presentation without written permission of the speaker is prohibited.

• © Phoenix Noise & Vibration, LLC 2016 Learning Objectives

• Acoustic Terminology • Codes relating to multifamily • Control • indoor noise transmission • mechanical noise • outdoor noise • Apply principals in daily designs Always remembering… That they make guitars and pianos out of wood, don’t they… Overview

Codes & Room to Room Noise Terminology Control

Wood Structures

Mechanical Noise Outdoor to Indoor Control Noise Control Codes

• Building Officials and Code Administrators International (BOCA) – (1999) • International Building Code (20xx) • International Residential Code • International Code Council

• Green Construction Code Agency Unit Types STC/ASTC IIC/FIIC BOCA 45/na 45/na (1999)

IBC Between Units, Corridor, or Common Spaces 50/45 50/45

IRC Living Units 45/na 45/na

Group R from Aor F 60/55

Group R from R, B, I or M 50/45 ICC Group R Condos from R Condos, B, I, M or R 55/50

Group R from R, A1, A2, A3, B, E, I, or M 50/45

Dwelling Units from each other and from public service areas 50/45 50/45 DC Dwelling units from Group A‐2 55/50 Codes

• Other codes or guidelines deal with:

• Outdoor to indoor noise control

• Mechanical impact upon adjacent properties

• Primarily today, let us concern ourselves with interior noise. FSTC Terminology dBA IIC STC NC ASTC

OITC Terminology • Loudness measured in deciBels (dB)

• dB = 10 x log(Pressure2/refPressure2)

• Human Range: 0 to 130 dB

• “A‐weight” to simulate human hearing…dBA

Terminology

• Why dB??? • Example of the logarithmic nature: Change in dB Subjective Response 3 dB Barely Perceptible 5 dB Clearly Perceptible 10 dB Twice as Loud

• Eases Comparisons: 30 to 33 = “Barely Perceptible” 90 to 93 = “Barely Perceptible” Terminology

•Everything is based upon the decibel scale •It’s the fundamental unit of measure Terminology

• There are noise barriers and there are noise absorbers.

• Barriers are not absorbers. • Absorbers are not barriers. • Many times the absorber is somewhat acoustically transparent.

• Barriers are generally composed of dense, heavy material layers. (Quiz Later) Quiz

• Barrier or Absorber?

• Barrier Quiz

• Barrier or Absorber?

• Absorber Quiz

• Barrier or Absorber?

• Barrier Quiz

• Barrier or Absorber?

• Absorber Quiz • Barrier or Absorber?

• This is of absolutely no use to the acoustician except to keep beer cold! Room to Room Noise Control Teminology

Sound Transmission Impact Insulation Class (STC) Class (IIC) Terminology

• Transmission Class (STC) – a single number rating of the partition’s ability to block from one side to another. Room to Room

STC Applies to Both Floor/Ceiling Systems And Walls Room to Room

STC ASTC Subjective Description 30 22‐25 Most sentences clearly understood

40 32‐35 Speech can be heard with some effort

50 42‐45 Loud speech can be heard with some effort

60 52‐55 Loud speech essentially inaudible 70 62‐65 Loud heard faintly 75+ Most noises effectively blocked

Credit: Architectural : Principles and Design 1999 Room to Room Quiz… Room to Room

• STC developed for speech, applied to many other noise sources such as:

• Mechanical • Transportation • Music

• Warning: Not always accurate for these other sources Room to Room

• Impact Insulation Class (IIC) ‐ A single number rating used to compare the effectiveness of floor/ceiling assemblies in providing reduction of impact‐generated sound such as footsteps. Room to Room

IIC Only Applies to Floor/Ceiling Systems Room to Room

• The popularity of hard surfaced floors in condominiums has brought a lot of attention to IIC ratings.

• Most Any Carpet and pad > 60 IIC • Hard floors < 40 IIC

• But Remember…

• IBC standard is 50 IIC 50 to 55 IIC Application Depending upon Underlayment Underlayments: Choose Wisely!

• There are numerous underlayments on the market • Many are copies of originals • Make sure there is a test from a third party laboratory • Make sure the test is of your system So you go on line to buy some underlayment… No, No, No…

Get documentation!

Underlayments: Choose Wisely!

• Make sure the test is of your system! Application

• One cost effective way to add STC and IIC points to a wall or floor/ceiling system is through the use of Resilient Channel

• Cost effective, but…

• NOT SO SIMPLE…

• (This really needs much more time…) Resilient Channel

Single Legged, RC‐1 Double Legged, RC‐2 (Dietrich RC Deluxe) Resilient Channel

Works in floor/ceilings too… With The Double Legged… Resilient Channel –Yes! The #1 Problem with RC

Courtesy of Pliteq Inc. Resilient Channel –NO’s! Quiz: What’s the Difference?

• Insert UL U311 detail For Very High STC & IIC Mechanical Noise

• A forest of condenser on the roof…directly above the most expensive units in the building. Condenser Noise

• Location, location, location… • Above non‐noise sensitive rooms such as corridors • Aids in the air‐borne noise • But structure‐borne…not so much Condenser isolation

Outdoor to Indoor Noise Control Transportation Noise

• Planes, Trains, & Automobiles • On‐site measurements • Computer Modeling • HUD Noise Guidebook • Ldn or Leq in dBA Local Transportation Interior Noise Level Requirements

State/City/County Roadway/Railway Airport Virginia 45 dBA Leq NA HUD 45 dBA Ldn 45 dBA Ldn Anne Arundel 45 dBA Leq 45 dBA Ldn Howard 45 dBA Ldn 45 dBA Ldn DC NA NA Baltimore City NA NA Fairfax 45 dBA Ldn 45 dBA Ldn Loudoun 45 dBA Leq 45 dBA Ldn HUD 45 dBA Ldn 45 dBA Ldn Outdoor to Indoor

• Transportation Noise • Computer Modeling • Building Shell Analysis • Common Building Elements • Windows and Doors: The Weak Link • OITC Building Shell Analysis

• Calculates a room’s interior noise level based upon: • Exterior Noise Level • Composite STC Rating • Windows, Doors • Walls, Roof • Miscellaneous • Room Size & Volume • Room

• Can be either very general or very detailed Exterior Wall STC

Building Element STC Common to All Constructions Rating Exterior Walls Brick 56 Vinyl Siding 39 2 x 4 wood studs, an exterior layer of ½” Vinyl Siding w/RC 45 OSB or plywood, 3” of fiberglass batt insulation, 5/8” interior layer of drywall Fiber Cement (Hardi) Siding 43 Fiber Cement w/ RC 47 Window & Door STC

Building Element STC Rating Construction ½” Insulated Window 28 1/8” glass, ¼” air space, 1/8” glass 1” Insulated Window 35 ¼” glass, ½” air space, ¼” glass 5/8” Laminated Insulated 35 Two 1/8” panes laminated together, ¼” air Window space, 1/8” glass Standard Patio Door 29 ½” glass mounted in polystyrene frame Upgraded Patio Door 36 1”; dual glazed unit composed of 3/8” laminated glass, ½” air space, and 1/8” double strength glass Windows and Doors: The Weak Link OITC • Outdoor‐Indoor Transmission Class: an A‐weighted single number rating of the transportation sound reduction effectiveness of a partition that separates an indoor space from the outside. • STC – Speech Frequencies • OITC – Transportation Frequencies

Window STC Rating OITC Rating ½” Insulated 28 26 5/8” Laminated, 35 31 Insulated Outdoor to Indoor Design Challenges • Restrictions on Exterior Façade Finishes • Lots of Glass • High STC Rated Windows and Doors = $$$ • Green Building Design • Bigger Windows • Fresh Air Openings In Review…

Codes & Room to Room Noise Terminology Control

Wood Structures

Mechanical Noise Outdoor to Indoor Control Noise Control Thank You for the Attention!

Questions?

Earplugs? Discussion? Acoustical Engineering Solutions