Bradford Acoustics

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D E S I G N G U I D E

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I n s u l a t i o n D e s i g n G u i d eACOUSTIC


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A C O U S T I C D E S I G N G U I D E

C S R B R A D F O R D I N S U L A T I O N2

Introduction 2

Product Range, Applications& Selection Guides 3 13

Bradford Acoustic Solutions

Party & Inter ior WallsResidential & Commercial 14

External Walls 18

Roof/Ceiling Systems 18

Floor/Ceiling Systems 23

Floors 24

Plumbing 25

Gutters & Downpipes 26

Pipes, Tanks & Vessels 27

Factories & Workshops 27

Acoustic Baffles 29

Acoustic Enclosures 30

Vibration Damping 34

Air Conditioning Systems 36

Bradford Acoustic Solutions forSpecialty Applications

Home Cinema 46

Auditor iums 47

Sports Complexes 48

Canteens/Restaurants 50Karaoke/Night Clubs 50

Shopping Centres 51

Recording Studios 52

Heavy Plant 53

OEM Application 53

Appendix A The Nature of Sound 54Sound Transmission 57Flanking Paths 59Sound Absorption 59

Reverberation 61Room Acoustics 64Industrial Acoustics 67Speech Privacy 68

Appendix B Floor/Ceiling Systems 69 70

Appendix C Product Data 71Sound Absorption Coefficients 74Static Insertion Loss/Silencers 77Air Flow Resistivity 78

Appendix D Terminology 79

CSR Bradford InsulationRegional Contact Details 80

Contents. Introduction.The Bradford Insulation Group forms part of the

Building Materials Division of CSR Limited. CSR

Bradford Insulation manufactures and markets an

extensive range of insulation products offering outstanding

thermal, acoustic and fire protection properties for use in

all types of domestic and commercial buildings.Two mineral fibre insulation types are available;

Bradford Glasswool, which is manufactured by

controlled felting of biosoluble glass wool bonded with

a thermosetting resin; and Bradford Fibertex Rockwool

which is spun from natural rock and bonded with a

thermosetting resin. Both are available in sheet or roll

form and as moulded pipe insulation.

Bradford Thermofoil and Thermotuff are a range

of aluminium foil laminates available in various grades.

All CSR Bradford Insulation products are tested to

meet stringent quality control standards incorporatingquality management systems such as AS3902/ISO9002.

ABOUT THIS GUIDE.

The purpose of this guide is to provide information on the

technical benefits obtained with the inclusion of acoustic

insulation materials in the construction of all types of buildings

as well as noise control of machinery.

The range of Bradford products and their applications

is presented along with data and worked examples to

illustrate design considerations.

This Acoustic Design Guide also outlines the basicproperties of sound, and methods for its control. It does not

set out to provide a definitive solution to every conceivable

noise problem. Rather, it aims to explain the principles

involved, so that these principles can be applied along with

common sense, to overcome common acoustic problems.

Acoustics is however a complex science, and there will

be many instances where the services of specialist acoustic

consultants or noise control engineers are indispensable.

The reader is cautioned against investing large sums of

money in noise control without first seeking advice.

This is particularly pertinent where compliance withnoise abatement orders is concerned.

TECHNICAL ASSISTANCE.

To assist designers, a free and comprehensive technical

service, as well as advice and assistance in specifying and using

Bradford products is available from CSR Bradford Insulation

offices in your region. Further technical data and product

updates are also available on the CSR Building Solutions

Website: www.csr.com.au/bradford

Information included in this Design Guide relates to

products as manufactured at the date of publication. Asthe CSR Bradford Insulation policy is one of continual

product improvement, technical details as published are

subject to change without notice.

Contents.


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The Importance ofAcoustic Insulation.

The minimisation of noise has become a significant environmental issue in the modern world,whether at home, at work or on holidays.

CSR Bradford Insulation manufacturers and distributes an extensive range of insulation products

that provide excellent noise control properties, as well as the traditional thermal and fire control

benefits.

Although all fibrous insulation products can provide some acoustic benefits, CSR Bradford

Insulation has a range of products specifically designed and tested for the acoustic insulation market,

including:

ACOUSTIC INSULATIONPRODUCT

Bradford Glasswool Partition Batts

Bradford SoundScreen

Bradford ACOUSTICON

Bradford Glasswool

R1.5 ACOUSTITUFF Ductliner

Bradford Glasswool

R1.5 ULTRAPHON Ductliner

Bradford ACOUSTICLAD

Bradford Glasswool ACOUSTILAG

Bradford FIBERTEX Acoustic Baffle

Bradford Glasswool SUPERTEL

Bradford Rockwool FIBERTEX 450

APPLICATIONS

Economical insulation for internal wall sound absorption

in housing, residential apartments or commercial offices.

Various systems are available to meet building codes.

Unique rockwool insulation system to reduce room-to-

room noise transmission in houses.

Commercial and residential metal roofing insulation

specially developed to reduce rain noise.

Air conditioning duct internal lining product offering full

enclosure with excellent sound absorption properties.

High performance acoustic absorption product for

ducting, silencers and other acoustic applications.

Wall absorber combining the superior acoustic properties

of Bradford Fibertex Rockwool with a perforated metal

panel system.

Pipe insulation product combining the noise barrier

properties of loaded vinyl and the absorption benefits ofglasswool. Ideal for noisy plumbing.

Rockwool batt enclosed in white polymer film used for

which is designed to be hung from the overhead structure

to provide acoustic absorption in a room or workplace.

General purpose medium density glasswool acoustic

insulation.

General purpose premium rockwool acoustic insulation

product.


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22 Ceiling

Tiled Roof

Sarking

66AcousticFloor/Ceilings

Floating Floors

77 Home Cinema

55 Plumbing

11 Metal Roofing

Bradford Insulation Application &Selection Guide for Homes.

Insulation Application Product Type Product Range/Facings

Bradford ACOUSTICON Blanket Medium, Heavy Duty

or Specialty THERMOFOIL

Bradford Glasswool ANTICON Blanket R1.5, R2.0, R2.5 Faced Light,

Medium, Heavy Duty


Bradford FIBERTEX Rockwool R1.5, R2.0, R2.5 Faced Light,

ANTICON Blanket Medium, Heavy Duty


Bradford THERMOFOIL Sarking Medium, Heavy Duty,

ANTIGLARE

Bradford THERMOTUFF Sarking Medium, Extra Heavy Duty, Safety

Bradford Glasswool Gold Ceiling Batts R2.0, R2.5, R3.0, R3.5, R4.0

Bradford FIBERTEX Rockwool

Ceiling Batts R2.0, R2.5, R3.0

Bradford ACOUSTILAG 2.5 - 5.0mm

Loose Fill Bags

Bradford Glasswool Partition Batts 50, 75 and 100mm

Bradford Rockwool SoundScreen 75mm

Bradford Glasswool Gold Wall Batts R1.5, R2.0


Wall Batts R1.5, R2.0


Cavity Wall Granulated Loose Fill Bags

Bradford ACOUSTILAG Pipe Insulation ACOUSTILAG 20, 23 and 26

Bradford HANDITUBE Pipe Insulation Stocked by CSR Bradford Insulation

Bradford FIBERTEX Rockwool Ceiling Batts R1.5 - R2.0

Bradford Glasswool Wall/Floor Batts R1.5 - R2.0

Bradford FIBERTEX Rockwool Wall/Floor Batts R1.5 - R2.0


Bradford Glasswool QUIETEL Specialty installation system

Bradford Glasswool SUPERTEL Specialty facings available


33Acoustic Internal

Walls

44 External Walls


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77Home Cinema Wall, Floor &

Ceiling Insulation.

Acoustic Absorbing Panels

Acoustic Insulation for Homes.

11

Tiled Roof Sarking or

Metal Roof Insulation

22Ceiling

Insulation

44External Wall

Insulation

55Plumbing

Insulation

33Internal Wall

Insulation

66Acoustic Floor/Ceiling &

Floating Floor Insulation


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22 Ceiling

Tiled Roof

Sarking

66AcousticFloor/Ceilings

Floating Floors

77 Home Cinema

55 Plumbing

11 Metal Roofing

Bradford Insulation Application &Selection Guide for Homes.


Bradford ACOUSTICON Blanket Medium, Heavy Duty


Bradford Glasswool ANTICON Blanket R1.5, R2.0, R2.5 Faced Light,

Medium, Heavy Duty


Bradford FIBERTEX Rockwool R1.5, R2.0, R2.5 Faced Light,

ANTICON Blanket Medium, Heavy Duty


Bradford THERMOFOIL Sarking Medium, Heavy Duty,

ANTIGLARE

Bradford THERMOTUFF Sarking Medium, Extra Heavy Duty, Safety

Bradford Glasswool Gold Ceiling Batts R2.0, R2.5, R3.0, R3.5, R4.0


Ceiling Batts R2.0, R2.5, R3.0

Bradford ACOUSTILAG 25mm 50mm

Bradford Glasswool Partition Batts 50, 75 and 100mm


Bradford Glasswool Gold Wall Batts R1.5, R2.0


Wall Batts R1.5, R2.0


Cavity Wall Granulated Loose Fill Bags


ARMAFLEX Pipe Insulation Stocked by CSR Bradford Insulation

Bradford FIBERTEX Rockwool Ceiling Batts R1.5 - R2.0

Bradford Glasswool Wall/Floor Batts R1.5 - R2.0

Bradford FIBERTEX Rockwool Wall/Floor Batts R1.5 - R2.0


Bradford Glasswool QUIETEL Specialty installation system

Bradford Glasswool SUPERTEL Specialty facings available


33Acoustic Internal

Walls

44 External Walls


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Acoustic Insulation for Commercial Buildings

11Ceiling Insulation

(Suspended Grid Ceilings

& Concrete Roof/Soffit)

22Internal

Partition Wall

Insulation

33Acoustic

Absorbing

Panels

44

Plumbing

Insulation

55Plant Room Wall &

Ceiling Insulation

66Fan Silencer & Fan

Casing Insulation77Air Conditioning

Duct Insulation

(Rigid & Flexible Ducts)


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Bradford Glasswool ANTICON R1.5, R2.0, R2.5 Faced Light,and ACOUSTICON Blanket Medium, Heavy Duty


Bradford FIBERTEX Rockwool R1.5, R2.0 Faced Light,ANTICON Blanket Medium, Heavy Duty or

Specialty THERMOFOIL

Bradford Glasswool SUPERTEL 25 75mmTHERMOFOIL Facing

Bradford FIBERTEX 350 Rockwool 50 - 100mmTHERMOFOIL Facing

Bradford Glasswool Ceiling Panel Overlays Factory Applied Acoustic Facings

Bradford FIBERTEX RockwoolCeiling Panel Overlays Factory Applied Acoustic Facings

Bradford Glasswool Building Blanket R1.2, R1.5, R1.8, R2.0, R2.5

Bradford FIBERTEX

RockwoolBuilding Blanket 50, 75mm, R1.5, R2.0

Bradford Glasswool Partition Batts 50, 75, 100mm

Bradford FIBERTEX Rockwool Partition Batts 45, 70mm

Bradford Glasswool ULTRATEL Board 25-100mm, Factory AppliedFacings

Bradford FIBERTEX 450 Rockwool 25-100mm,Factory Applied Facings


ARMAFLEX Pipe Insulation Stocked by CSR Bradford Insulation

Bradford Rockwool/Glasswool ACOUSTICLAD

Bradford Glasswool FLEXITEL

, Perforated 750PSUPERTEL, ULTRATEL THERMOFOIL

Bradford FIBERTEX 350 Rockwool Perforated 750PTHERMOFOIL

Bradford Glasswool FLEXITEL Perforated 750P

Bradford Glasswool SUPERTEL THERMOFOIL

Bradford Glasswool QUIETEL ACOUSTITUFF

Bradford FIBERTEX Rockwool DUCTLINER ULTRAPHON

Bradford Glasswool SUPERTEL BMF, ULTRAPHON

Bradford Glasswool ULTRATEL 25 100mm

Bradford Glasswool QUIETEL (Quietel 13mm - 50mm)

Bradford FIBERTEX Rockwool DUCTLINERBradford FIBERTEX 450 Rockwool

Bradford Glasswool SUPERTEL Perforated 750P THERMOFOIL

Bradford Glasswool DUCTLINER ULTRAPHON,

Bradford Glasswool ULTRATEL ACOUSTITUFF facings

Bradford FIBERTEX Rockwool DUCTLINER 25 100mm, R1.5 & R0.9

Bradford Glasswool MULTITEL R1.5 & R0.9

Bradford Glasswool FLEXITEL 25 100mm

Bradford Glasswool THERMOGOLD DUCTWRAP

Bradford FIBERTEX Rockwool DUCTWRAP

Bradford Glasswool R1.0 SPECITEL R1.0. R1.5

Bradford FABRIFLEX Flexible Ducting Available ex-Singapore

Bradford ACOUSTIFLEX Flexible Ducting Available ex-Singapore

Bradford Insulation Application & SelectionGuide for Commercial Buildings.

11Concrete

Roof/Soffit

Exposed Grid

Ceiling

Concealed Grid

Ceilings

22Acoustic Internal

Partitions

77Rigid Ducting

Internal Lining

44 Plumbing Insulation

Rigid Ducting

External Wrap

Flexible Duct

55Plant RoomWall & Ceiling

Insulation

66 Fan Casings

Fan Silencers

33Acoustic

Absorbing

Panels


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Acoustic Insulation for Theatre, Sports& Multi-Purpose Buildings

22Sports Centre

Roof/Ceiling Insulation

Floor Insulation

Acoustic Absorbing

Panels

33Canteen

Wall Insulation

Ceiling Insulation

Acoustic Absorbing Panels

Metal Deck Rain Noise Insulation

11

Auditorium/Theatre/Cinema

Roof/Ceiling Insulation

Wall Insulation Acoustic Absorbing

Panels

44Air Conditioning

System Insulation


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Insulation Application Product Type

Walls

Bradford Glasswool Partition Batts

Bradford Rockwool Partition Batts

Acoustic Absorbers

Bradford Glasswool FLEXITEL, SUPERTEL

ULTRATEL with BMF (Black Matt Facing Tissue),

ULTRAPHON or other specialty facing.


Bradford ACOUSTICLAD Wall/Ceiling Absorber

Roof/Ceiling

Bradford Glasswool ACOUSTICON

Bradford Glasswool Ceiling BattsBradford Rockwool Ceiling Batts

Acoustic Absorbers






Roof/Ceiling


Bradford Glasswool Ceiling Batts

Bradford Rockwool Ceiling Batts

Acoustic Absorbers






Walls

Bradford Glasswool Partition BattsBradford Rockwool Partition Batts

Roof/Ceiling


Bradford Glasswool Ceiling Batts


Refer to CSR Bradford Insulation Air Conditioning Design

Guide and Product Guide.

22Sports

Buildings

Swimming

Basketball

Gymnasium

33Canteen

Facility

11Theatre, Cinema

& Auditorium

44Air Conditioning

Systems

Bradford Insulation Application & Selection Guidefor Theatre, Sports & Multi-Purpose Buildings.


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Acoustic Insulation forIndustrial Applications.

66Ceiling

Insulation

11Acoustic Baffles

(suspended)

88Acoustic Wall

Absorbers 77Metal Deck

Roof Insulation

44Acoustic

Absorbing

Screens

55Acoustic Internal

Wall Insulation

33Bradford Insulation

for OEM Applications

22AcousticEnclosures for

Plant & Machinery


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33 OEM Applications

22Acoustic Enclosures

for Plant & Machinery

44Acoustic

Absorbing Screens

77Metal Deck

Roofs

88Acoustic Wall

Absorbers

66 Ceilings

11Acoustic Baffles

55Acoustic Internal

Walls

Bradford Acoustic Insulation forIndustrial Applications.


Bradford FIBERTEX

Acoustic Baffle Fully enclosed in white polymer film ready to hang.

Bradford FIBERTEX Rockwool 25 100mm

Bradford Glasswool FLEXITEL Density 24 120kg/m3

Bradford Glasswool SUPERTEL

Bradford Glasswool ULTRATEL

Bradford Glasswool Appliance Grade Cut to size with specialty facings

Bradford Rockwool Appliance Grade available

Bradford Glasswool QUIETEL

Bradford Glasswool SUPERTEL 25 100mm


Bradford Glasswool Partition Batts To fit studs

Bradford FIBERTEX Rockwool Partition Batts

Bradford Glasswool Ceiling Batts 50 150mm


Bradford Glasswool ACOUSTICON 75mm

Bradford Rockwool ACOUSTICON

Bradford ACOUSTICLAD 25 100mm

Bradford FIBERTEX

Rockwool Specialty facings available


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Interior Walls.RESIDENTIAL PARTY &

INTERNAL WALLS.

The Building Code of Australia (BCA) Sections F5 setsout Sound Transmission Class (STC) requirements for

sound insulation of floors, walls, between units, walls

between bathrooms, laundries, kitchens, between habitable

and non-habitable rooms in multi-tenancy buildings. In

late 1999, the BCA changed its acoustic rating from STC

to Sound Reduction Index (Rw). This Acoustic Design

Guide uses the STC rating units as Australasia and Asia are

familiar with STC and it is very similar to Rw. An increase

of either one STC unit or one Rw unit approximately

equals a reduction of one decibel in noise level.

Table 1 below shows common STC values of walls

used in buildings. The expected audibility for a given

STC level is also shown, based on guidelines for ambient

sound levels

TABLE 1. STC AND AUDIBILITYTHROUGH WALLS AND FLOORS.

STC Value Audibility

30 - 35 Speech audible

40 Loud speech, still heard

45 Loud speech, just heard

50 55 Speech cannot be heard

The BCA Part F5.4 Sound Insulation Of Walls

Between Units currently states a wall must have an STC

not less than 45. It has been proposed to increase this to

STC 55 in the future as STC 45 does not provide enough

acoustic privacy. STCs 50 are standard in Europe and

USA.

Generally internal walls for residential applications in

Australia use either rendered brick or lightweight double

leaf walls using plasterboard and/or fibre cement

construction on timber studs.

To improve or increase the sound transmission loss

(STL) hence the STC of these walls, the following is

required:-

EXTRA MASS.

Sound Transmission Loss (STL) depends heavily on

the surface density of a building element (mass per square

metre of surface). For every doubling of surface density,

the sound transmission loss increases by about 5dB.

The addition of denser wall sheeting products such as

CSR Gyprock Fyrchek or Soundchek plasterboard or

CSR Fibre Cement together with Gyprock Resilient

Mounts and furring channels can reduce noise levels.

DOUBLE-LEAF WALLS.

Higher transmission losses than those expected by the

Mass Law can be obtained by using double-leaf walls

with an air cavity.

Further increases in sound transmission loss,

particularly at low frequencies can be achieved by using

wider air cavities.

When a double leaf wall is uninsulated, the air in the

cavity can act as a spring, efficiently transmitting sound

energy from one side of the wall to the other.

Significant improvement in STC is obtained by

using Bradford Rockwool or Glasswool batts in the

cavity.

Acoustic tests of walls around the world have shown

the use of glasswool batts or rockwool batts inside cavity

walls reduces resonances between the two sheets and can

significantly improve the acoustic performance by up to

10 STC. Generally the thicker and/or denser the

insulation in the cavity, the higher the STC rating

resulting in less noise transmitted to the other side of the

wall. The actual improvement in STC depends on the

type of wall construction. Insulation in the cavity will also

lessen the effect of the coincidence dip in double leaf

walls.

FLANKING NOISE.

It should be noted that actual installations, as compared

to acoustic laboratories, exhibit flanking noise through

doors, windows, ventilation ducting, air gaps at ceiling,

wall and floor intersections. In addition, poor

workmanship may degrade the acoustic performance of

partitions. For these reasons, a building element

constructed in the field will usually achieve a lower STC

ratings than when tested in the laboratory.

Maximum acoustic performance can be achieved by

eliminating penetrations in walls, caulking gaps, and

staggering electrical outlet or other necessary penetrations

through the wall. Wall cavities should be completely

filled with insulation and tightly fitted around pipes,

conduits and other outlets.

Bradford Acoustic Solutions.


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LOW FREQUENCY NOISE.

Low frequency noise from sources such as fans, aircraft,

road and rail traffic, and bass from amplified music can

penetrate walls easier than high frequency noise.

Therefore higher sound transmission loss (ie. higher

STC) walls are required to ensure satisfactory acoustic

performance. As a general rule, add at least 5 STC points

to the acoustic requirement of the walls when lowfrequency noise is present.

STC data for some typical partition walls is given in

Table 2. Further STC data for internal cavity walls is

available the CSR Bradford brochure Noise Reductions

For Internal Partitions or the CSR Gyprock Fire &

Acoustic Design Guide, The Red Book.

TABLE 2. STC DATA FOR TYPICAL TIMBER FRAME PARTITION SYSTEMS.

Description STC (Rw) STC (Rw) STC (Rw)

Bradford Bradford

No Glasswool Rockwool

Insulation Wall Batts Wall Batts

STC 30 - 42

1 layer 10mm CSR Gyprock Plasterboard CD

70/75mm Timber Studs

1 layer 10mm CSR Gyprock Plasterboard CD

STC 40 - 50

2 layers 13mm CSR Gyprock Fyrchek plasterboard

70/75mm Timber Studs

1 layer 13mm CSR Gyprock Fyrchek plasterboard

STC 50 - 60


90 x 35mm Staggered Timber Studs


33 38 39(75mm Batts) (45mm Batts)

Test CSR 37/67

42SoundScreen

43 47 48

(50mm Batts) (45mm Batts)

51 58 59


* Refer to the CSR Bradford Noise Reduction of Internal Partitions brochure or the CSR Gyprock Fire & Acoustic

Design Guide (The Red Book) which show a wide range of internal partitions and their STC ratings.


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Internal plasterboard or fibre cement walls using steel

stud systems are widely used in commercial construction

and offer a wide range of sound transmission loss

performance.

The methods stated previously for improving acoustic

performance of Residential Internal Walls also apply to

the Commercial Internal Partitions.

Thinner gauge steel studs, with greater stud spacing

and minimum fixing of sheets to studs also results in a wall

which is able to flex more easily generally resulting in

slightly higher acoustic performance.

If higher STC performance is required, there are a

number of steps that can be incorporated at the time of

construction to improve acoustic performance, as detailed

in Table 3.

TABLE 3. INSULATION FOR NOISE REVERBERATION CONTROL.

Addition STC Improvement Comments

Fit insulation into studs Up to 10 STC points Thicker and/or denser insulation

such as Rockwool is beneficial.Light gauge or deeper steel studs give

higher STC performance.

Use Gyprock Fyrchek Up to 3 STC points Use of 13mm or 16mm CSR

plasterboard if installed both sides Gyprock Fyrchek improves

performance due to extra mass.

Gyprock Resilient Channel 6 8 STC points Resilient Channel isolate the

one side Gyprock Plasterboard from the stud.

Bradford Quietel one side and 4 STC points Quietel board acts as a sound

insulation to stud isolator between the Gyprock

Plasterboard and the Stud.

Staggered and double studs Up to 10 STC points Provide sound breaks between solid

studs and Gyprock. Recommended

where impact isolation is also required.

Gyprock Resilient Mounts and Up to 10 STC points Used where high level reduction of

Furring Channel airborne and impact noise is required.

COMMERCIAL INTERNALPARTITIONS.


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* Refer to the CSR Bradford Insulation Noise Reduction of Internal Partitions brochure or CSR Gyprock Fire &

Acoustic Design Guide (The Red Book) which show a wide range of internal partitions and their STC ratings.

Description STC (Rw) STC (Rw) STC (Rw)

Bradford Bradford

No Glasswool Rockwool

Insulation Partition Batts Partition Batts

STC 30 - 40 1 layer 13mm Gyprock Plasterboard CD

64mm Steel Studs

1 layer 13mm Gyprock Plasterboard CD

STC 40 - 50

1 layer 16mm Gyprock Fyrchek

64mm Steel Studs


STC 50 - 60


plasterboard 64 x 0.75mm BMT Separated Steel Studs

1 layer 13mm Gyprock Fyrchek plasterboard

STC 55 - 60


64 x 0.75 BMT Separated Steel Studs


STC 60 - 70

2 layers 16mm Gyprock Fyrchek plasterboard

92 x 0.75mm BMT Separated Steel Studs 2 layers 16mm Gyprock Fyrchek plasterboard

TABLE 4. STC RATINGS OF SOME COMMERCIAL INTERNAL PARTITIONS*.

A sample of the STC ratings for commercial internal partitions using steel studs taken from the Tables in the CSR Bradford

Insulation Noise Reductions for Internal Partitions brochure, together with results from recent testing.

35 40 41


Test HAS 085

39 44 45


45 57 58

(75mm (75mm

Wall Batts) SoundScreen)

45 55 60

(80mm Batts) (75mm

SoundScreen)

55 63 64


CSR Bradford Insulation has available a sophisticated

Acoustic Predictor computer program, developed by CSR

Gyprock

, which can predict the STC rating of manydifferent internal partitions, in addition to those shown

above and in the brochure.

Note: For walls which require high sound transmission

loss STC greater than 50, such as those used between

recording studios or cinemas, flanking paths should be

considered, as they can derate the acoustic performance ofthe partition. For cinema walls requiring a very high STC

rating, contact CSR Bradford Insulation regarding the CSR

Gyprock Cinema Wall System, or other CSR systems.

ACOUSTIC PREDICTION SYSTEM.


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External Walls.External walls of residential buildings usually consist of

brick veneer construction, or lightweight concrete

construction,

a cladding material, usually timber or fibre cement or

occasionally double brick.

For better acoustic performance, use building materialswith more mass. Clay bricks provide high surface density

(or mass per square metre) to enable high transmission

loss.

The use of CSR Gyprock Soundchek or Fyrchek

plasterboard is recommended for interior walls. For even

higher wall STC, the use of CSR Gyprock Resilient

Mounts and Furring Channels is recommended.

For brick veneer walls add the thickest possible

rockwool or glasswool batts inside wall cavities during

construction of the building.Granulated rockwool can be retro-fitted into existing

walls of a building using a special machine which blows

granulated rockwool under pressure into the wall cavities.

Wall sheeting usually has solid connections (ie screw

or nail fixed) to the timber or steel studs and transmits

noise through these solid connections. CSR Gyprock

Resilient Mounts can reduce both noise and vibration

transmission.

To improve STC performance of single timber studs,

consider the use of Rondo resilient channels or CSR

Gyprock resilient mounts with furring channels, which

can improve STC (or Rw) by 6 to 8.

Buildings with double brick walls should use vibration

isolated wall ties to reduce the amount of noise and

vibration transmitted from one wall to the other.

Note that building elements of low acousticperformance will derate the improvements made to other

building elements ie. walls and ceilings. For example,

lightweight windows and doors can reduce the overall

STC rating of the wall.

Products.

Bradford Glasswool Wall Batts

Bradford Rockwool Wall and Ceiling Batts

Roof/Ceiling Systems.Roof/ceiling systems generally consist of either steelroofing or tile roofing. These roofing systems usually

provide average to poor acoustic performance and can be

an acoustically weak link in a building facade. It should

be noted that consideration should be given to other weak

links in the building extensions such as windows and

doors.

Low frequency noise generated by aircraft, road and

rail traffic can easily penetrate commonly used building

materials including the roofing.

Tile roofs are generally used in domestic applications.

It is recommended that Bradford Rockwool or Glasswool

Ceiling Batts be used in the roof cavity to improve both

acoustic and thermal resistance. Note the higher the

thermal resistance or R-value, the thicker the batt, and

the better the acoustic absorption.

The following points indicate methods to improve the

acoustic performance of a typical tiled roof system. Tips

on how to further improve the STC rating are provided

in (brackets)

Rockwool or glasswool insulation batts on top of the

ceiling, (the thicker the insulation or the higher the

R-rating, the better the acoustic absorption)

Using a heavy THERMOFOIL sarking as a

condensation barr ier under the roof tiles, the heavier

the better the noise reduction.

Adding Bradford SOUNDLAGG loaded vinyl over

the ceiling joists, (the heavier the better).

Thicker and/or heavier plasterboard for the ceiling,

(use fire rated plasterboard and multiple layers).

Care should be taken to minimise all gaps in the roof

ceiling to maximise the acoustic performance.GyprockPlasterboard

BradfordThermofoil orThermotuffBreather

BradfordInsulationWall Batts

ExternalCladding

Timber Frame

FIG 1.

EXTERNAL WALL INSULATION.


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Figure 2 shows how to improve the acoustic

performance of a typical tiled roof system.

Note that the gaps inherent in tile roof construction

allow noise to enter the roof cavity. Hence the use of

rockwool or glasswool insulation will maximise noise

absorption in the roof space, minimising the amount of

noise entering the room/s below.

Steel roofing is used in both commercial and

residential roofing systems in Australia, New Zealand

and Asia.

Metal deck roofing systems require a layer of thermal

insulation faced with a suitable vapour barrier to be

installed directly underneath the metal decking to guard

against condensation.

Figure 3 shows the improvement in STC of a typical

domestic roof with the addition of Bradford insulation in

the roof/ceiling system.

Bradford Glasswoolor Rockwool CeilingBatts (as indicated)

Bradford Thermofoil 733Sarking over rafters

Gyprock 10mmSupa-CeilPlasterboard Ceiling

CeilingJoist

Monier ConcreteRoof Tiles

Bradford Soundlagg(6kg/m2) over joists

FIG 2. IMPROVING ACOUSTIC PERFORMANCE OF TILED ROOF SYSTEMS.

SYSTEM

Monier concrete tile roof with one

layer of Gyprock Supa-Ceil

plasterboard fixed to ceiling joists

spaced at 600mm centres.

Add Bradford R2.5 Glasswool Batts

between joists.

Replace Bradford R2.5 Glasswool

Batts with Bradford R3.0 FIBERTEX

Rockwool Building Batts between

joists, and install Bradford

THERMOFOIL 733 over rafters.

Add Bradford SOUNDLAGG

(6kg/m2) over ceiling joists.

STC/Rw

33

41

45

50

Bradford FibertexRockwool Batts or(Bradford G lasswoolCeiling Insulation inNew Zealand)

Metal Roofing

Gyprock 10mmSupa-CeilPlasterboard Ceiling

CeilingJoist

Bradford AcousticonFoil Faced Blanket

FIG 3. IMPROVING ACOUSTIC PERFORMANCE OF STEEL ROOF SYSTEMS.

SYSTEM

Metal roofing with 1 x 10mm Gyprock

Supa-Ceil plasterboard fixed to ceiling

joists spaced at 600mm centres.

Add Bradford ACOUSTICON

foilfaced building blanket over rafters under

metal roofing.

Add Bradford R2.5 FIBERTEX

Rockwool Building Batts between joists.

Replace Supa-Ceil plasterboard with 2

layers x 13mm Gyprock Plasterboard CD

fixed to metal furring channels (at

600mm max. cts) attached by Gyprock

Resilient Mounts

Metal roofing with one layer plasterboardfixed to ceiling joists spaced at 600mm

cts. plus Bradford Ceiling Insulation

between joist. (New Zealand only).

STC/Rw

34

41

45

52

39 41

TILED ROOF SYSTEMS.

STEEL ROOFING SYSTEMS.


20/80



The STC of a roof system (commercial, industrial or

domestic) can also be improved with the addition of

heavier building materials such as:

addition of insulation between the roof sheeting and

Bradford batts above the ceiling,

thicker steel roof sheeting,

using heavier, fire rated plasterboard or multiple layers

for the ceiling,

installing a layer of Bradford SOUNDLAGG beneath

(4 kg/m2 or heavier).

RAIN NOISE REDUCTIONWITH METAL DECK ROOFING

A common problem of steel roofing is that of rain

noise, particularly in tropical climates with high levels of

rainfall. Rain falling on metal deck roofing can cause

unacceptably high noise levels in the space below the roof.

The impact causes the stiff lightweight roof sheeting to

vibrate, thus emitting noise. Damping the vibration of the

roof sheeting reduces the emitted noise.

Rockwool and glasswool blanket products have

exceptional noise absorbing properties providing effective

damping of the steel roof sheeting.

CSR Bradford Insulation in conjunction with CSR

Gyprock have constructed a rain noise testing facility to

simulate rain noise using conventional 0.42mm thick

BHP Trimdek Hi-Ten metal roof cladding. The rain

noise test rig has four nozzles spraying water at high

pressure simulate high intensity rainfall. Continuous noiselevels of 89dB(A) were created inside the test rig, this

noise level was used for controlled testing purposes.

Figure 4 shows the rain noise insertion losses achieved

by using Bradford Insulation Blankets faced with

Thermofoil 729. All tests used 0.42mm BMT BHP

Trimdek Hi-Ten steel roofing.

Bradford ACOUSTICON Glasswool Roofing

Blanket is faced with THERMOFOIL.

ACOUSTICON has been specially developed to

provide cost effective rain noise reduction of 18dB(A)

insertion loss under metal deck roofing.

ACOUSTICON has BHP approval for use under all

types of Lysaght steel roofing profiles, including Klip-Lok.

For more information refer to the Bradford

ACOUSTICON A Quiet Step Forward brochure,

available from your nearest Bradford office.

For optimum rain noise reduction under steel roofing

in commercial, industrial and residential applications,

install 75mm Bradford ACOUSTICON.

For residential applications, ensure the correct rating of

thermal insulation is achieved for roof insulation in your

region. At least R2.0 Bradford Rockwool or Glasswool

Ceiling Batts should be installed between ceiling joists in

conjunction with a Bradford ACOUSTICON.

CSR Bradford Insulation and CSR Gyprock have

conducted many tests using various foil faced roofing

insulation blankets, ceiling tiles and fixed plasterboard

ceilings. The results of these are shown in Table 5.

In tropical climates, roofing insulation is generally

installed foil face up, ie. the foil in direct contact with the

metal deck roof sheeting. This reduces the insertion loss

of the roofing blanket by 2dB. The use of Bradford

Rockwool ACOUSTICON is therefore recommended.

Rain noise tests were conducted using the same

thickness/density glasswool blanket and varying the

surface density of foil. It was found that the mass of the

foil has no effect on the rain noise insertion loss achieved

by the insulation.

ACOUSTICON and ANTICON roofing blankets

should be installed so the blanket is firmly in contact with

the steel roofing as shown in Figure 5. This has the

added benefit of damping the metal roof sheeting and

reducing rain noise.

10 11 12 13 14 15 16 17 18 19 20

Insertion Loss db(A)

50mm Glasswool blanket

50mm Bradford Rockwool

75mm Bradford ACOUSTICON Optimum

50mm Polyester Blanket

FIG 4

RAIN NOISE REDUCTION INSERTION LOSSES

FOIL FACED ROOFING BLANKETS.

BradfordAcousticon

Support Mesh(when specified)

Bradford ThermofoilVapour Barrier

Metal Deck Roofing

Purlin

FIG 5.

REDUCTION OF RAIN NOISE METAL DECK ROOF.


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TABLE 5. NOISE REDUCTION CEILING SYSTEMS.

Ceiling System Description Rain Noise

Reduction Level

dB(A)

Bradford ANTICON R1.5 Blanket hard under metal deck roof

Bradford ACOUSTICON hard under metal deck roof

Bradford FIBERTEX

Rockwool ACOUSTICON

hard under metal deck roof

Rondo Suspended Concealed Grid Ceiling System.

1 layer x 13mm Gyprock Plasterboard CD.

Bradford ANTICON R1.5 Blanket hard under metal deck roof

Rondo Suspended Exposed Grid Ceiling System.

CSR Gyprock Ecophon 20mm Lay-in Ceiling Tiles.

Bradford ANTICON R1.5 Blanket hard under the roof.

RONDO Suspended Exposed Grid Ceiling System.

CSR Gyprock CELOTEX 16mm Lay-in Ceiling Tiles.


RONDO Suspended Exposed Grid Ceiling System.

Gyprock 13mm Lay-in Ceiling Tiles.


RONDO Suspended Concealed Grid Ceiling System.



RONDO Suspended Concealed Grid Ceiling System.


Bradford R1.5 GOLD BATTS or R1.5 Glasswool Building Blanket laid over the ceiling.


RONDO Resiliently Mounted Suspended Concealed Grid Ceiling System.

2 layers x 13mm Gyprock Fyrchek Plasterboard.

Bradford R1.5 GOLD BATTS or R1.5 Glasswool Building Blanket laid over the ceiling.

15

18

19

22

25

30

34

37

45

51

Products for Metal Deck Roofing Systems.

Bradford Glasswool Acousticon 75mm. (R1.8)

Bradford 50mm Commercial Grade Anticon

. Bradford Glasswool R1.5 Anticon 55mm.

Bradford Glasswool R2.0 Anticon 75mm.

Bradford Glasswool R2.5 Anticon 95mm.

Bradford 50mm Rockwool ACOUSTICON.

CEILINGS.

Fixed plasterboard ceilings generally provide better

sound transmission loss (ie. higher STC) than lightweight

suspended ceiling tiles and even plasterboard ceiling tiles.

This is because the fixed plasterboard ceiling is bettersealed and has less gaps. Multiple layers of plasterboard

with resilient mounting and rockwool or glasswool batts

in the cavity can provide high STC rating. The larger the

Refer to the CSR Gyprock Fire & Acoustic Design Guide (The Red Book) for additional information on rain noise

reduction ceiling systems. See comments regarding: Tropical climate applications in Bradford ACOUSTICON brochure.

ceiling cavity, the better the low frequency noise

reduction.

The ceiling can be an important area of a room to

place sound absorption particularly, when the remainder

of the rooms contains hard reflective surfaces. Rooms

having no sound absorbent surfaces typically have high

reverberation times. This results in poor acoustics,

particularly if communication is required within the

room.

Generally commonly used plasterboard ceilings,

whether fixed or lay in ceiling tiles are not very effective

at absorbing sound.

Typically, sound absorptive ceilings generally consist

of:

ceiling tiles made of high density rockwool or

glasswool (typically NRC 0.70 0.95),


22/80



perforated plasterboard or perforated metal pan ceilings

with Bradford Rockwool or Glasswool insulation

(faced with a black tissue) above (good sound

absorption NRC 0.60 0.90),

Mineral fibre ceiling tiles (average sound absorption

NRC 0.50 0.60).

Note that better low frequency acoustic absorption

results when ceiling tiles are installed with an air cavity.The larger the air cavity, the better the low frequency

acoustic absorption.

In many commercial office buildings, noises such as

conversations, telephones r inging etc can be heard from

one office to another (also known as Crosstalk). This can

cause disruption, annoyance, and decreased productivity.

Crosstalk usually occurs from sound flanking via the

ceiling.

In commercial office buildings, the walls are built up

to the underside of the lightweight suspended ceilings(usually a metal grid), not to the concrete slab above. The

lightweight ceilings tiles used generally have a low STC

rating. The void above wall and ceiling allows sound to

flank from one room to the next via the acoustically

weak ceiling tiles. Ideally, the wall should be built up to

the underside of the floor above without gaps for sound

to pass from one side to the other.

To reduce the amount of sound flanking when a wall

does not continue to the underside of the floor above, it

is recommended that Bradford Rockwool or Glasswool

Ceiling Batts be installed between the wall/ceiling and the

underside of the floor above. The more compressed the

insulation is when installed in this way, the better the

acoustic performance. refer to Figure 6.

Alternatively, to reduce flanking via the ceiling, install

Bradford Acoustilag from the underside of the concrete

slab to the ceiling below as shown in Figures 7 and 8.

Products - Ceilings.

Bradford Rockwool Ceiling Batts R1.5, R2.0, R2.5,

R3.0. Bradford Glasswool Ceiling Batts R2.0, R2.5, R3.0,

R3.5, R4.0.

Bradford Glasswool Ceiling Panel Overlays (optional

Black Matt Facing, or ULTRAPHON)

Bradford Glasswool Absorption Blanket (optional

Black Matt Facing or ULTRAPHON

Bradford Fibertex Rockwool (optional Black Matt

Facing or ULTRAPHON)

Ducting

Ducting

Poor sound privacy caused by sound flankingthrough lightweight suspended ceiling

FIG 6. IMPROVING SOUND TRANSMISSION

CONTROL THROUGH CEILING AREA WITH

BRADFORD INSULATION.

Ducting

Ducting

Improved privacy with Bradford Rockwool or

Glasswool Ceiling Batts in ceiling space over wall

BradfordRockwool orGlasswoolPartition Batts

Bradford Rockwool or GlasswoolCeiling Batts compressedbetween ceiling and slab above

CablingDucting

NOTE: Care must be taken when passing cables through

insulation material due to possible overheating. Consult

your electrician for more details.


23/80



Floor/Ceiling NoiseControl Systems.

Multi-storey buildings with hard flooring such as

timber, parquetry or tiles etc., can efficiently transmit both

airborne and impact noise (structure borne vibration) to

the rooms below if appropriate techniques are not

incorporated at the time of construction. Installing carpetand underlay on the floor can significantly reduce the

impact noise to the room below.

Installing R2.0 or greater, Bradford Rockwool or

Glasswool batts between the floor joists will reduce

airborne noise by approximately STC 4 6.

At the time of printing this guide, The Building

Code Of Australia (BCA) Sound Insulation of Floors

Between Units stated a floor separating sole occupancy

units must have an Rw of not less than 45. (Note: Rw

45 approximately equals STC 45). Floors must alsoprovide insulation against impact generated sound.

It should be noted that STC 45 is not always adequate

in reducing airborne sound through floors and walls. For

better acoustic privacy, it is preferable to use a higher

rating of say Rw 50 or preferably Rw 55.

RETRO-FIT OF VIBRATIONISOLATED FLOOR.

To reduce impact noise transmission through

floor/ceiling systems on existing timber, concrete or

tiled floors, a floating floor can be constructed on top ofthe existing floor.

The floating floor should use a resilient damping

material. Dense Bradford Rockwool, Glasswool or rubber

materials can be used but care is needed to choose a

material with the correct stiffness for the application and

static load. The services of an acoustic consultant should

be engaged to solve floor impact noise problems and for

the design of floating floors.

Floating floors should not be mechanical fixed (nailed

or screwed) to the existing floor as this will couple the twofloors resulting in very little damping. The resilient

material should also be used between the edges of the

floating floor and the walls of the building. Skirting

boards should also be isolated or separated from the

floating floor.

Note the floor/ceiling and floor/door heights may be

affected by the use of a floating floor. Doors may also need

undercutting if a floating floor is retro-fitted. Therefore

where clearances are important, the floating floor height

should be kept to a minimum.

C-track or timberbatten fixed to soffit

Bradford Acoustilagcurtain continuous inceiling area

Suspended ceilingtiles/plasterboard

250mm minimum

100mmminimum

FIG 7. IMPROVING SOUND TRANSMISSION

CONTROL THROUGH CEILING AREA WITH

BRADFORD ACOUSTILAG CURTAIN.

75mmBradfordReinforcedAluminiumTape

50mm min.overlap

BradfordAcoustilagcurtain

FIG 8. JOINTING ABRADFORD ACOUSTILAG CURTAIN.

Cut Bradford Acoustilagcurtain to allow installationaround pipes, ducting etc.

A tight fit should bemaintained to ensureacoustic integrity

PENETRATIONS THROUGH

BRADFORD ACOUSTILAG CURTAIN.


24/80



REDUCING NOISE TRANSMISSIONTHROUGH TIMBER

FLOOR/CEILING SYSTEMS.

1. Fit Bradford R2.0 (or greater) Floor Batts, or

Rockwool/Glasswool Ceiling Batts tightly between

ceiling joists.

2. Fix one layer of 13mm or 16mm Gyprock Fyrchek

plasterboard to furring channels.3. For better acoustic performance (to reduce airborne

noise), choose a ceiling with more mass ie. multiple

layers of Gyprock plasterboard CD or Gyprock

Fyrchek plasterboard.

4. CSR Gyprock Resilient Mounted Furring Channels

will further improve acoustic performance as well as

impact isolation.

5. To improve impact isolation of floors, use carpet and

good quality thick underlay over timber flooring.

A large range of floor/ceiling systems incorporating

alternative acoustic upgrades is detailed in Appendix B of

this publication.Refer to the CSR Gyprock Fire & Acoustic Design

Guide The Red Book for additional information on

floor/ceiling systems.

REDUCING NOISE TRANSMISSIONTHROUGH CONCRETE

FLOOR/CEILING SYSTEMS.

For concrete floor ceiling constructions, use vibration

isolated ceiling hangers or resiliently mounted furring

channels to support the plasterboard ceiling.

Products.

Bradford Floor Batts.

Bradford Glasswool R2.0, R2.5, R3.0, R3.5, R4.0

Ceiling Batts.

Bradford Rockwool R1.5, R2.0, R2.5, R3.0

Wall/Ceiling Batts.

Bradford Glasswool Quietel (for impact isolation).

Floors.Improved air-borne sound reduction and impact

isolation can be achieved by using floating floors as shown

in Figures 11, 12 and 13.

High density, resilient Bradford Rockwool or

Glasswool Quietel can break the sound and vibration

transmission paths while having sufficient compressive

strength to support the floating floor and the room

contents. Vibrational energy is absorbed in the resilient

material rather than transmitted to the building structure.

Not only does a floating floor achieve effective structure-

borne sound control, but it also reduces the air-borne

sound transmission to and from the room below.

The Bradford Fibertex Rockwool or Glasswool

Quietel board are laid flat on the floor, ensuring all joints

are tightly butted. At the edges of the rooms, the battscontinue up the walls. For the concrete floor, waterproof

film is then used to cover the batts and a concrete screed

floor of suitable thickness is poured.

Carpet and underlay

Timber flooring

Gyprock resilient mount

Use higher density Gyprock plasterboard(Soundchek or Fyrchek) and/or multiple layers

Furring channel

BradfordGlasswool or

RockwoolInsulation

Timber joists

FIG 9. TYPICAL METHODS FOR IMPROVING

ACOUSTIC PERFORMANCE OF A TIMBER

FLOOR/CEILING SYSTEM.

Carpet and underlay

Concrete slab floor

Suspended ceiling system

Gyprock resilient mount

Higher density Gyprockplasterboard (Soundchek orFyrchek) and/or multiple layers

Furring channel

Bradford Rockwool orGlasswool Insulation

FIG 10. TYPICAL METHODS FOR IMPROVING

ACOUSTIC PERFORMANCE OF A CONCRETE

FLOOR/CEILING SYSTEM.

SYSTEM

19/20mm Timber Flooring,

200 x 50 Timber Joists at 450mm

centres, 1 layer x 13mm Gyprock

plasterboard CD.

Add Bradford R2.0 GOLD BATTS

between joists.

Add Gyprock Resilient Mounts and

Furring Channels at 600mm centres

between joists and plasterboard.

Add Carpet and Underlay. Add second

layer of 13mm Gyprock plasterboard CD

STC/Rw

35

39

52

55


25/80



VIBRATION RESISTANCE.

As Bradford Fibermesh Rockwool is stitched to

wire mesh, the blankets are especially resistant to fallout

under conditions where vibration is present.

Bradford Fibermesh is particularly suitable for

applications involving both vibration and high

temperature where standard bonded insulation materials

are less resistant to the effects of vibration.

Products.

Bradford Glasswool QUIETEL.

Bradford FIBERTEX HD Rockwool.

Bradford FIBERTEX HD (High Density) Rockwool.

Bradford FIBERMESH Rockwool.

Plumbing.Noisy pipe work is a common problem in many

buildings. These days, pipe work building trendscommonly use inexpensive, lightweight, easily to install

materials with thin wall thicknesses which are

unacceptably noisy. Offices, hotels, apartments and

domestic houses can all benefit from reduced soil and

waste pipe noise levels. Designers, hydraulic consultants,

engineers, plumbers, owners and occupants of buildings

should all take steps to insulate pipes and ducts to reduce

noise.

Water flowing through commonly used PVC soil and

waste pipes is predominantly high frequency noise. Toeffectively reduce pipe noise, lag the pipes with Bradford

Acoustilag 20, 23 or 26 pipe insulation. The 20, 23, and

26 indicate the A-weighted [dB(A)] insertion loss

achieved by lagging PVC pipes with each of the Bradford

Acoustilag product respectively. (Refer to Appendix B

for additional information).

Note, the 20, 23 and 26dB(A) insertion losses only

apply to water flowing through PVC pipes which have

been correctly lagged with Acoustilag. Using Acoustilag

for lagging other noise sources, eg., a fan casing or sheet

metal air ducts, will generally result in lower insertion

losses to those quoted, as these noise sources have more

low frequency noise energy.

To achieve the insertion losses quoted, Bradford

Acoustilag should be installed with all joins of the

lagging overlapped or butted, tightly and taped with

Bradford 493 reinforced foil tape. Minimising all the

gaps increases the acoustic performance of the lagging.

The Building Code of Australia (BCA) states that: Soil

and waste pipes are to be separated if a soil or waste

pipe, including a pipe that is embedded in or passesthrough a floor, serves or passes through more than one

sole-occupancy unit:

Timberbattens

Particleboardor timber board flooring

Structural floorAir gap at wall

BradfordFibertex Rockwoolor Glasswool Quietel

PlywoodSheeting

FIG 11 TYPICAL FLOATING FLOOR TIMBER OVER

CONCRETE.

Floorfinish

50mmConcrete

Wire mesh

Structural floor Waterproof film

BradfordFibertex Rockwoolor Glasswool Quietel

FIG 12 TYPICAL FLOATING FLOOR CONCRETE

OVER CONCRETE.

Gyprockplasterboardceiling

BradfordQuietel Board

Timberflooring

Plywoodsheeting

Plywoodsheeting

Bradford Glasswool/RockwoolCeiling Batts

FIG 13 TYPICAL FLOATING FLOOR TIMBER OVER

TIMBER JOIST CONSTRUCTION.

All equipment is then mounted on the screed floor

which is acoustically isolated from the main building

structure.

NOTE: The upper plywood layer should not be nailed

or screw fixed to the timber below. Instead, it should float

on the base floor to effectively damp vibration. The floor

should also be isolated from the walls. CSR Bradford

Insulation recommends consulting an acoustic engineer

for the design of floating floor systems.


26/80



(a) The pipe must be separated from the rooms of any

sole-occupancy unit by construction with an STC not

less than:

(i) STC 45 if the adjacent room is a habitable room

(other than a kitchen); or

(ii) STC 30 if the adjacent room is a kitchen or any

other room.

The Bradford ACOUSTILAG Pipe Insulationbrochure provides systems using CSR Gyprock

plasterboard to achieve the STC noise criteria specified by

the BCA. The STC 50 system specified in that brochure

is intended for applications requiring better acoustic

isolation from waste pipe noise than is specified in the BCA

eg., board rooms, offices, apartments and hotels etc.

To achieve the STCs specified in Table 6, it is

imperative that the pipes be correctly lagged (no gaps to

allow noise leakage), and the plasterboard ceiling and walls

above be airtight with no gaps into the next room.It is recommended the services of an acoustic

consultant or acoustic engineer be used to achieve

specified STC ratings. Penetrations, ducting, light fittings,

gaps in ceilings etc., can degrade the acoustic rating of the

lagging and ceiling system.

To minimise annoyance from plumbing noise, it is

advisable, at the design stage, to avoid placing bathrooms

and laundries etc., adjacent to noise sensitive areas.

Methods for minimising plumbing noise include:

Select vibration isolated pipe hangers to support pipesand minimise transmission of vibration into the

building structure. These will reduce water hammer

noise when turning the water taps on or off.

Alternatively use ARMAFLEX insulation between

pipes and the building structure.

Use water supply and drain pipes that are oversized, this

may reduce line pressure and minimise flow noise.

Where possible, use cast iron waste water pipes in place

of lightweight plastic pipe to substantially reduce

plumbing noise. The heavier, stiffer walls of cast iron

pipes effectively reduce noise.

If plastic waste water pipes must be used, use Bradford

ACOUSTILAG to effectively reduce noise.

Insulate all pipes and plumbing that are chased into

brick walls.

Select quieter plumbing equipment and appliances eg.cisterns, washing machines, clothes dryers etc.

Products.

Bradford ACOUSTILAG 20, 23 or 26.

Bradford 493 reinforced foil tape.

ARMAFLEX insulation.

Quietening Box Gutters

& Downpipes.Box gutters should be insulated with BradfordFLEXITEL or SUPERTEL Glasswool (25mm thick)

faced with heavy duty foil. Insulation can be attached to

gutters using 45mm long Bradford self-adhesive fasteners

and washers at 300 mm centres. Insulation should be held

firmly against the metal surface for maximum dampening.

For better noise reduction, use Bradford ACOUSTILAG 20.

Noisy downpipes should be insulated with Bradford

Glasswool Sectional Pipe Insulation faced with Heavy

Duty Thermofoil. Alternatively a 25mm wall thicknessARMAFLEX pipe insulation or Bradford

ACOUSTILAG 20 can be fitted around downpipes.

Products.

Bradford Glasswool FLEXITEL or SUPERTEL.

Bradford ACOUSTILAG 20.

TABLE 6. ACOUSTIC INSULATION SYSTEMS FOR PLUMBING.

System STC/Rw Bradford CSR Gyprock BradfordN Rating. ACOUSTILAG Plasterboard Insulation

BAS 01 30 ACOUSTILAG 20 1 layer 10mm NilGyprock CD

BAS 02 45 ACOUSTILAG 20 2 layers 13mm CSR 75mm BradfordGyprock CD Glasswool R1.5

BAS 03 45 ACOUSTILAG 23 2 layers 10mm CSR 75mm BradfordGyprock CD Glasswool R1.5

BAS 04 50 ACOUSTILAG 23 2 layers 13mm CSR 100mm Bradford

Gyprock CD

Glasswool, R2.0BAS 05 50 ACOUSTILAG 26 2 layers 13mm CSR 75mm Bradford

Gyprock CD Glasswool R1.5

Refer to the Bradford ACOUSTILAG brochure for additional information.


27/80



Insulation Cladding ofPipes, Tanks & Vessels.

The insertion loss achieved by cladding pipes, tanks

and vessels will depend on a number of factors such as the

frequency of the fluid in the pipe the type and mass of

the cladding material, the thickness and density of the

(rockwool or glasswool) insulation.

It should be noted that some of these cladding systems

can actually amplify the noise at lower frequencies,

particularly if insulation with a high density is used. This

generally happens as the tank now has a larger radiating

surface. Therefore it is difficult to predict the insertion loss

of cladding systems.

It should be noted that Bradford Rockwool or

Glasswool SPI (sectional pipe insulation) will reduce pipe

noise but not as effectively as Bradford ACOUSTILAG

or insulation with a mass barrier. Higher density, meansit is less resilient than Bradford ACOUSTILAG and

more efficiently transfers noise and vibration from the pipe

to the cladding/barrier. Note: Bradford ACOUSTILAG

is not recommended for high temperature applications.

Refer to the CSR Bradford Industrial Insulation

Design Guide for installation details of cladding and pipe

lagging.

Factories & EngineeringWorkshops.

The basic methods by which industrial noise may be

controlled are:

Sound absorption absorbing the noise using mineral

fibre materials which can dissipate the sound energy

as heat.

Sound insulation (enclosing) containing the noise in

one area so that it does not cause annoyance in other

areas.

Vibration damping damping vibrating surfaces toreduce air borne sound emission.

Vibration isolation preventing acoustic energy from

entering the building structure.

These processes are illustrated in Figure 14. As the

figure shows, treatment of a factory noise problem often

involves a combination of the basic processes.

REVERBERATION CONTROL.

Factories and engineering workshops usually are

reverberant spaces due to the lack of sound absorption

within the space. Areas with multiple noise sources, such

as factories, engineering workshops, bottling plants,

machine halls, plant rooms etc usually have a high level

of reverberant noise often exceeding the safe regulatory

noise level of 85dB(A).

The use of sound absorbing materials (such as

glasswool and rockwool) to reduce reflected or reverberant

sound is the most effective means of reducing overall

sound levels in enclosed areas.

CSR Bradford Insulation manufacture a range of

rockwool and glasswool products with outstanding soundabsorption properties. These products have been tested

in acoustic reverberation rooms to determine the sound

absorption coefficients presented in the technical data

section.

A range of factory-applied facings is available, the

most common being:

black fibreglass tissues (BMF), or ULTRAPHON

THERMOFOIL laminates (solid and perforated).

An extremely effective acoustic absorber for walls

and ceilings is Bradford ACOUSTICLAD a roll

formed panel, factory lined with Bradford FIBERTEX

350 Rockwool. Each panel interlocks with its neighbour

forming a structurally reinforced joint.

Bradford ACOUSTICLAD offers excellent test

results with NRC ranges from 0.9 to 1.05. Contact CSR

Bradford Insulation for a brochure or refer to Appendix

C for the Bradford ACOUSTICLAD absorption

coefficients in 1/3 octave bands.

Vibration Damping of fancasing reduces soundemission

Insulationreduces soundflow to outside

Absorbent Liningreduces sound levelwithin enclosure

Vibration IsolationMounting reducesvibration transmissionto floor

FIG 14. BASIC NOISE CONTROL METHODS.


28/80



Bradford ACOUSTICLAD perforated metal is

available with percentages of open area ranging from

10% to 55% and in a number of finishes including:

galvanised steel,

powder coated steel,

stainless steel and

aluminium.

Fixing details for Bradford ACOUSTICLAD are

available from your nearest Bradford office.

Bradford Rockwool and Glasswool insulation is

available with a range of facings, including:

perforated metal or expanded metal.

perforated foils,

pegboard,

wire,

plastic mesh.

Any perforated sheet facing should have an open area

greater than 10% to maximise acoustic absorption.

Other common methods for acoustic wall treatment

involve:

fixing timber battens or steel furring channels or Z

sections at a spacing to suit the facing sheets. Bradford

Rockwool and Glasswool batts are cut to size if

necessary and friction fitted between the supports. The

protective facing (e.g. perforated or expanded metal,

plastic mesh, pegboard, wire etc.) is fixed to thefurring sections or battens by nails, screws, or rivets

as appropriate. Cover strips are used to improve the

appearance.

A commonly used cost effective method for fixing

insulation (generally faced with perforated foil) on walls

and ceilings uses drive pins and speed clips. These

eliminate the need for battens or furring channels. The

drive pins are fixed to the wall usually at 450mm centres.

The insulation is pushed through the pins and held onto

the pin by the speed clips of a suitable size.

Rigid facings such as perforated metal or pegboard are

unsuitable for this application method. The advice of

adhesive suppliers should be sought before using

adhesively fixed pins in lieu of drive pins.

Ceilings may be lined by the same methods as walls.

An alternative approach is to use a fully exposed metal

suspension grid which makes it a simple matter to achieve

any air gap required behind the batts

Factories contain noise which predominantly has most

energy at low frequencies which is difficult to absorb

unless very thick insulation is used. To increase the low

frequency sound absorption of perforated noise absorbers

(such as Bradford ACOUSTICLAD), introduce an air gap

behind the insulation. This can be achieved by using larger

battens or furring channels with chicken wire to retain the

batts in position, as shown in Figure 15 below. Better

acoustic absorption results when the depth of the air cavity

is at least as thick as the insulation.

Alternatively, rockwool or glasswool insulation greater

than 75mm can be used with acoustically transparent

facings mentioned above.

Acousticlad Test Sample Configuration Noise Reduction

Perforated Coefficient

% Open Area NRC Rating

15% 50mm thick Bradford FIBERTEX 350 Rockwool

(60kg/m3) Insulation with black matt facing (BMF) 1.00

between the Rockwool and Acousticlad face.

25% as above 0.95

40% as above 1.00

15% 23mm thick Mylar film between unfaced Bradford

FIBERTEX 350 Rockwool and ACOUSTICLAD 0.90

perforated aluminium.

15% 50mm thick Bradford FIBERTEX 350 Rockwool

Insulation with black matt tissue between the1.05

Rockwool and perforated aluminium. Timber spacers

supporting panels with average air gap 30mm.

TABLE 7. ACOUSTICLAD TEST RESULTS.

Notes All acoustic tests were conducted with ACOUSTICLAD perforated aluminium panels (0.7mm thick), with Bradford 50mm thickFIBERTEX 350 Rockwool (60kg/m3) insulation.

Acoustic tests were conducted in the reverberation room at the National Acoustic Laboratories, Chatswood, Sydney, Australia. See Appendix C for absorption coefficients at each 1/3 Octave band frequency.


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Products.

ACOUSTICLAD with perforated metal facing is

available in various thicknesses and open area

percentage to accommodate acoustic absorption

requirements.

The following Bradford products can also be used:

Bradford Rockwool FIBERTEX 350, 450.

Bradford Glasswool FLEXITEL, SUPERTEL,

ULTRATEL with perforated metal, expanded metal,

wire, meshes or perforated heavy duty grade foil facings.

Bradford Acoustic Baffles.Large factories or buildings may need a greater area of

acoustic absorbing insulation than just the wall area, or may

need it concentrated in a particularly noisy section of thebuilding.

Bradford Rockwool Acoustic Baffles may be suspended

in any desired pattern to achieve extra sound absorption

in a building. Refer to Figure 16 and 17.

Sound absorption coefficients of Bradford Rockwool

Acoustic Baffles are shown in Table 8.

BAFFLE INSTALLATION.

Two popular methods of installation are detailed.

Baffles may be installed at any height, and do not need

to be all in the same plane. A regular pattern such as

parallel rows or a staggered, cross-hatched pattern is most

easily installed using a suspended ceiling grid.

Determine the number of acoustic baffles to be

installed to meet the noise reduction required. The typical

number of baffles is 1 baffle per square metre of ceiling

area. Allowance should be made for lights and sprinklers.

Installation Method 1.

The baffles can be individually suspended from the

roof structure using S hooks, galvanised wire or fine

chain. In this case, suspend baffles approximately 1

metre below the ceiling level if possible.

Chicken wire Structual wall Air gap

BradfordFibertexBatts

Facingeg. perforatedmetal

Battens

FIG 15.

ABSORPTIVE LINING WITH AIR GAP TO BOOST

LOW FREQUENCY ABSORPTION (PLAN VIEW).

FIG 16.

BRADFORD ACOUSTIC BAFFLES USED TO

ABSORB SOUND FROM NOISY EQUIPMENT.

'S' Hook

Roof framing

Bradford Acoustic Bafflesin cross-hatch pattern

Suspensionwire or chain

FIG 17.

ACOUSTIC BAFFLES SUSPENDED AND ARRANGED

IN A CROSS-HATCH PATTERN.

TABLE 8. SOUND ABSORPTION COEFFICIENTS OF BRADFORD ACOUSTIC BAFFLES.

Product Density Thickness Facing Frequency (Hz)(kg/m3) (mm) 125 250 500 1000 2000 4000 5000 NRC

Bradford Acoustic Baffle 60 50 30m 0.18 0.44 0.83 1.25 1.14 0.96 0.94 0.90

plastic film


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Installation Method 2.

Inverted 50mm x 12mm aluminium U-channels are

fixed to the underside of a ceiling grid. The baffles are

then secured to the U-channel using self tapping screws.

Products.

Bradford Rockwool Acoustic Baffles.

Acoustic Enclosures.Enclosures are an effective method of reducing noise

emitted from a particular machine or noise source. They

should be constructed of solid materials such as bricks,sheet steel, timber, plasterboard etc. Enclosures reduce

noise more effectively when they are airtight, with no

gaps or openings. This is not always possible as the

machinery inside may need to be accessed by other

machines or people, or require air flow for cooling.

Enclosures built around machinery actually

concentrate the noise inside the enclosure. Therefore it

is good practice to line the inside of enclosures with

Bradford Rockwool or Glasswool to reduce reverberant

noise levels inside.A simple acoustic enclosure is shown in Figure 19. It

has three main components:

(i) an internal lining of sound absorbent rockwool or

glasswool insulation to reduce the noise level inside

the enclosure.

(ii) a heavy barrier to reduce sound transmission to the

outside.

(iii) a resilient pad of felt or rubber to isolate the enclosure

from the floor (optional).

Broadly speaking, the sound transmission loss of anenclosure improves by about 5dB for every doubling of

the surface density (mass per square metre or kg/m2).

Thus, a 2mm thick sheet steel enclosure will reduce the

noise level by about 5dB more than a 1mm sheet steel

enclosure, assuming all other conditions are equal.

Enclosures do not attenuate all frequencies of sound

equally, so the transmission loss achieved will depend on

the frequency spectrum of the noise source. High

frequency noise is more easily attenuated than low

frequency noise.

Thus, while a lightweight enclosure may provideeffective transmission loss for a high frequency noise

source, it could however be inadequate for low frequency

noise sources.

Flanking transmission paths permit sound to by-pass

the acoustic enclosure. Typical examples are air gaps,

windows, doors, service penetrations etc. To avoid severe

reductions in insulation performance, steps should be

taken to eliminate these flanking paths as far as practical.

Caulking of air gaps and penetrations, use of door seals

or even double doors, resiliently mounted double glazing,

use of flexible couplings on pipes and ducting which

penetrate the enclosure are all means of reducing flanking

transmission.

Flanking through the floor of an enclosure can limit

the transmission loss. Sound and vibration entering the

floor on the noisy side of the enclosure can be re-radiated

to some extent on the other side.

The sound insulation performance of lightweight

enclosures may be significantly improved by the use of

double-leaf construction with a core of sound absorbing

rockwool or glasswool as shown in Figure 20. The

performance will be further enhanced if the two leaves

are of different surface densities eg: one leaf may be

1.6mm steel sheet while the other is 1.2mm steel sheet.

This reduces resonant coupling between the sheets.

The sound reduction achieved depends on the surface

density of the enclosure. Heavy materials like steel sheet

greater than 1.0mm, 16mm plywood or 19mm particle

board are typically used.

As well as trapping sound, enclosures of the type

shown in Figure 19 and 20 will also trap heat. It is oftennecessary therefore to ventilate these enclosures to avoid

overheating of the enclosed machinery. Ventilation

openings must also be acoustically treated to reduce the

escape of sound through these openings. The use of

packaged attenuators, insulation lined ducts or acoustic

louvres are commonly used.

Absorptive treatment may include not only lining

the walls and ceiling of an enclosure but also the use of

discrete screens or baffles. The latter are of particular

value where it is important that the absorptive treatmentdoes not interfere with the dissipation of heat. Where heat

could cause a problem, then Bradford Rockwool Acoustic

Baffles are specially designed for suspension below existing

Bradford Acoustic Bafflesarranged in parallel pattern

Aluminiumchannel

Mainsuspensiongrid

FIG 18.

ACOUSTIC BAFFLES FIXED IN ALUMINIUM TRACK

AND ARRANGED IN A PARALLEL PATTERN.


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Heavy duty flexible pipeconnection, and resilientmounted pipe/ductwork

Main structure ofbuilding

BradfordInsulationBlanket

Minimumcavity of200mm

Existingwindow

Smalldoubleglazedviewingwindow

Two steelsoundproofdoors with alledges sealed

Resilient/floating floorsystem

BradfordInsulationBlanket incavity



factory roofs. Their sound absorption performance is

detailed in the previous section. Baffles will not however

be as effective at reducing noise as an enclosure.

An example of an acoustic enclosure for very high

acoustic insulation is detailed in Fig 21. It shows a room

within a room. These rooms are vibration isolated from

each other.

INSTALLATION DETAILS.

Installation of the sound absorbing rockwool or

glasswool batts to the inside surfaces of the enclosure

proceeds in a similar manner to that previously described

for reverberation control.

Where double-leaf construction is employed a larger

number of variations are possible. One simple yet effective

procedure follows:

Construct a suitable frame using steel angles, channels,

or box sections to provide at least 63mm clearance

between the two leaves. (Note the wider the cavity, thebetter the low frequency sound transmission loss). Mount

this frame on a continuous thick rubber mat.

The outer steel sheeting should then be fixed to the

frame as shown in Figure 21, using rubber strips to

reduce sound transmission from the frame to the sheet.

Bradford Fibertex 450Rockwool or Ultratel

Heavy GaugeSteel Sheet

Rubber Mounting

FIG 19.

ACOUSTIC ENCLOSURE.

Bradford Fibertex 450Rockwool or Ultratel

Heavy GaugeSteel Sheet

Rubber Mounting

FIG 20.

ACOUSTIC ENCLOSURE WITH

DOUBLE-LEAF CONSTRUCTION.

FIG 21.

ACOUSTIC ENCLOSURE WITH VERY HIGH ACOUSTIC INSULATION.


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Fix 50mm thick FIBERTEX R350 to the inside of

the sheeting using weld pins and speed clips. Bend over

the ends of the pins if necessary to avoid contact with the

inner steel sheeting when installed.

The inner sheeting may now be fixed to the frame,

again as shown in Figure 21. The sound absorbing

rockwool or glasswool batts may now be fixed to the

inside of the inner sheet using weld pins, speed clips, anda suitable facing (wire, meshing, perforated foil).

Alternatively, a perforated metal (such as Bradford

ACOUSTICLAD) or expanded metal can be used, or

for an aesthetically pleasing finish.

Any gaps, openings or joins in the outer leaf of the

enclosure, should be caulked and doors should use

acoustic door seals.

Products.



ULTRATEL.

Bradford ULTRAPHON facing.

Partial Enclosures& Screens.

It is not always practical to totally enclose a noisy

machine. However, the use of a partial enclosure or

screening will still achieve some reduction in noise levels

particularly close to the screens. The previous discussion

on total enclosures also applies to partial enclosures.

However the overall noise reduction of partial enclosures

will not be as great, due to the openings.

As far as is practical, employee work stations should

be located in the shadow zone of the screening and not

in line with the openings in the enclosure. Reflective

surfaces near openings in a partial enclosure should be

treated with rockwool or glasswool insulation to absorb

noise.

Where a particular noise source contributes

significantly to the overall noise level in a room, it may

be controlled by a partial enclosure of the type shown in

Figure 22. Much of the sound produced within the

enclosure is absorbed, thus reducing the amount of sound

radiated into the room.

Partial enclosures can be simply fabricated by

sandwiching FIBERTEX Rockwool or Glasswool Batts

between an outer sheet of plywood and an inner lining

of pegboard. Alternatively, plain hardboard, particleboard,

plasterboard, or sheet metal may be used for the outersheet, while the inner lining may be perforated or

expanded metal. The effectiveness of a partial enclosure

depends in part on the weight of the outer sheet and the

percentage of the machinery that is enclosed.

FIG 22.

A PARTIAL ENCLOSURE.

FIG 23.

TYPICAL NOISE PROBLEM WITHOUT

ACOUSTIC ENCLOSURE .

FIG 24.IMPROVED NOISE CONTROL

WITH A PARTIAL ENCLOSURE.


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The choice of which type of Bradford FIBERTEX

Rockwool or Glasswool to use should be based on the

frequency spectrum of the noise source. Select the

material with the highest sound absorption for the

dominant frequency bands of the noise source. High

frequency sound absorption will be affected by the inner

lining. Should the dominant frequency bands of the

noise source be above 1000 Hz, the inner lining should

have a perforated open area of 11% or more to ensure

optimum sound absorption.

The effect of local absorption will be limited by the

need to provide access or ventilation to the equipment

concerned. However, local absorption permits reduction

in sound levels without significantly altering the room

reverberation time.

Figures 23 and 24 show a typical application of a

partial enclosure to reduce noise reaching an operator.

Figure 23 and 24 illustrate the use of partial acoustic

enclosures in a car assembly line application.

Products.



ULTRATEL.

Bradford ULTRAPHON or HD Perf. facings.

FIG 25.

TYPICAL NOISE PROBLEM WITHOUT ACOUSTIC ENCLOSURE.

FIG 26.

TYPICAL PARTIAL ACOUSTIC ENCLOSURE APPLICATION.


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ACOUSTIC SCREENS.

Simple acoustic screens may be fabricated as shown in

Figure 27, and these may be supported in any framing

suitable to the particular application. Screens can act in

three ways:

As local sound absorbers (i.e. a simple partial

enclosure),

As reverberation control (i.e. more absorption isintroduced to the room),

As a partial barrier (i.e. an acoustic shadow zone is

created behind the screen).

For maximum effect, acoustic screens should be

located as close as practical to the noise source or to

people affected by the noise. They should be as large as

possible, at least the height or width of the machine or

noise source. Air flow requirements should be considered.

Products.


Bradford Glasswool SUPERTEL, ULTRATEL.

Bradford ULTRAPHON facing.

NOTE: Where the noise level emitted by a factory is

above acceptable community standards, it is wise to

engage the services of a noise control engineer.

Environmental noise legislation is quite complex, and

failure to comply with the relevant noise criteria may

result in severe penalties. Each situation presents its own

unique problems which must be identified and then

corrected.

Vibration Damping.Vibrating surfaces such as fan casings, pipes, and

ducting can be a major source of noise. Lagging these

surfaces will significantly reduce the noise radiated from

the sources. When treating such surfaces in this manner,

it is essential that lagging be applied over the entire

sound-radiating surface. It is also necessary to avoid

bridging connections between the radiating surface and

the outer cladding. Otherwise, the vibration will be

transmitted directly to the cladding which will itself

become a sound-radiating surface.

VIBRATION ISOLATION.

Vibration isolation involves the isolation of vibrating

machinery from the building structure. In practice this is

achieved by using flexible, resilient mountings, such as

rubber-in-shear rubber or steel springs. Where equipment

is mounted on inertia block

Bradford Acoustics

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