Soundproofing of Wood-frame buildings

Learning objectives Basic Acoustic Principles and Definitions Impact and Airborne sounds in light wood-frame buildings Means of soundproofing light wood-frame buildings The Do s and Dont s

SOUNDPROOFING SOLUTIONS for: - Flooring - Ceiling - Wall - Plumbing

Problematic situations New York: 30 condos (120 000 sq.ft.) to fix = + $2M Quebec: 50 condos (50 000 sq.ft.) to fix (on going) = $$$$ Toronto: Hotel (100 000 sq.ft.) to fix = $500 000 Acoustic insulation is not an expense, but an investment!

Two types of noises STC (Sound Transmission Class) Airborne noises IIC (Impact Insulation Class) Impact noises

Airborne noises Talking TV Radio Pets

Laboratory testing for airborne noises measurement index (STC)

Airborne noise measurement index STC (Sound Transmission Class) FSTC (Field Sound Transmission Class) ASTC (Apparent Sound Transmission Class)

4 basic acoustic principles Mass (max. of 2 masses) Resilience & Decoupling (2 and more) Filling joist cavity (Phonic absorption) Sealing The importance of these principles in the design and implementation of a project All project collaborators; architects, engineers, general contractors and any worker on a construction site, must know these principles and implement them as precisely as possible

Impact noises Falling objects Moving furniture Walking / Running

Laboratory testing for impact noises measurement index (IIC)

Waves propagation in different materials

Impact noise measurement index IIC (Impact Insulation Class) FIIC (Field Impact Insulation Class) AIIC (Apparent Impact Insulation Class)

Sound level auditory perception Sounds can have different intensities and tones Tone depends on frequency: Low pitch sounds = low frequency High pitch sounds = high frequency Increasing sound level vs. change in auditory perception Increasing sound level Auditory perception 1 to 2 db Not perceptible +3 db Barely perceptible +5 db Audible difference +10 db Sensation is doubled +20 db Sensation is quadrupled

Influence of lateral transmission (flanking) on AIIC final result Flanking can negatively influence the result by 4 to 10 db and +... How to mitigate flanking in wood-frame buildings: 1. Acoustic treatment of interior walls in contact with the structure (acoustic insulation + resilient channel) 2. Interruption of structures continuity (wood and concrete topping) 3. Decoupling the floor covering and concrete topping 4. Decoupling the gypsum wallboards (drywall) and flooring 5. Decoupling the baseboards and quarter rounds

Decoupling

Building structure vs performance Concrete structure Light wood-frame structure

Building structure vs performance Cross-laminated Timber structure (CLT) Hambro structure

Light wood-frame structure as performant as concrete structure? Most of the time: low FIIC 50 Sometimes: high FIIC 50 NOW: possible to achieve as high as FIIC 69

Typical assembly of a wood-frame structure Assembly description: Engineered flooring Acoustic membrane 1 ½ Concrete topping Resilient material Boards (OSB or Plywood) I-joists or open web joists Acoustic insulation Resilient channels or acoustic suspensions Gypsum

STC (Sound Transmission Class) More predictable Tests performed in laboratory and on site 14 on site tests performed by an independant certified acoustician, variation of 53 to 63 db (average 58) Causes results variation: Quality in work execution Application of direct and indirect acoustic principles &

IIC (Impact Insulation Class) More difficult to predict Greater variation in results for identical assemblies Compilation of on site testing by independent certified acoustician and AcoustiTECH, variation of 45 to 65 db (average 59) Causes of results variation: Quality in work execution & Application of direct and indirect acoustic principles

Engineered flooring The choice of floor type influences the result The density and composition of the engineered flooring assembly can make a difference of 2 to 4 db

Acoustic membrane The choice of membrane influences the result For greater acoustic performance, membrane must be installed as close to the point of impact (difference of 2 to 5 db) (First decoupling) Two types of membrane installations: Floating Glued-down

1 ½ Concrete topping The presence of a concrete topping allows to multiply the quantity of resilient materials layers in the assembly (first mass) - A membrane on top and underneath The concrete type (light or standard) has little influence on the final result, but the mass weight plays a major impact

Resilient material It is important to isolate the concrete topping from the structure (second decoupling) Must be adapted according to the maximized efficiency load of the resilient material (compression) NOTE: The membrane quality and the application method can make a difference of up to 10 db

Wood boards Plywood or OSB (Oriented Strand Board)? OSB offers a slightly superior performance than plywood (1 to 2 db)

I-joists or open web joists «I» joists perform slightly better than open web joists (gain of 1 to 2 db)

Acoustic insulation For a better acoustic performance, the void must be at least 60% filled (ideally to 100%) Each 2 of insulation added increases the result by 1 db (max. 10 db) 1 gypsum = compacted acoustic insulation (more than 2.5 lbs) 2 gypsums = non-compacted acoustic insulation

Resilient channels and acoustic suspensions The addition of resilient channels (R/C) every 16 c/c rather than steel or wood furs will improve the assembly performance between 6 to 10 db It is best to install the R/C every 24 c/c rather than every 16 c/c (less contact points and a gain of 1 to 2 db) The distance between the R/C is determined by the weight of the selected gypsum (never surcharge the R/C) Maximum of two 5/8 gypsums «X» type Acoustic suspensions, compared to resilient channels, increase the performance of the assembly by 5 to 9 db The installation of acoustic suspensions is one of the key components to obtain a FIIC of 62 and more

Gypsum The apparent ceiling material becomes our second mass (one of the acoustic basic principles) It is best to always maintain the integrity of this surface NOTE: By doubling the gypsum boards, we improve the assembly performance by 4 to 5 db Two 5/8 boards («X» type) are better than two 1/2 pannels («X» type) (+2 db) Two 5/8 boards are better than one 1/2 board and one 5/8 board

Sealing The partition wall must be as air-tight as possible «Where air is flowing, the sound is too» Seal the mechanical ducts in the partition wall and ceiling (plumbing, ventilation, fire system, etc.) Preserve the integrity of the partition ceiling (pay attention to flushmounted lightning, sprinkler heads, ventilation ducts, etc.) Significantly influences overall result (+ 10 db)

Evolution of floor covering Carpet and Rug synthetic fiber natural fiber Resilient rubber cork linoleum vinyl leather Hardwood floor solid parquet prefinished engineered Ceramic and stone ceramic marble granite natural stone

Typical assembly of a light wood-frame structure Floor covering FIIC (usual average) FIIC achievable Engineered flooring FIIC 55 to 61 FIIC 65 to 69 Carpet FIIC 75 + FIIC 80 LVT (vinyl tiles) FIIC 54 + FIIC 66 to 69 Solid wood on plywood FIIC 54 to 58 FIIC 59 to 66 Ceramic FIIC 47 to 55 FIIC 57 to 62

SELECTION CRITERIA FOR AN ACOUSTIC MEMBRANE Acoustic performance Health and environment Life time and durability Mechanical strength Thermal value LEED Easy installation

There is no magic recipe: Every detail is crucial Acoustic insulation is not an expense, but an investment!