Environmental Science

By Tim South – licensed under the Creative Commons Attribution – Non-Commercial – Share Alike License

http://creativecommons.org/licenses/by-nc-sa/2.5/

Why it matters

Tim South

Leeds Metropolitan University

What are the acoustic issues in a What are the acoustic issues in a completed building?completed building?

Sound insulationSound insulation– Between dwellingsBetween dwellings– Between rooms in a buildingBetween rooms in a building

Reverberation in roomsReverberation in rooms

Internal noise levelsInternal noise levels– From building servicesFrom building services– From outsideFrom outside

Noise emitted from the buildingNoise emitted from the building

Any extra issues during Any extra issues during construction?construction?

Noise exposure of the workforceNoise exposure of the workforce

Hand-arm vibrationHand-arm vibration

Construction noiseConstruction noise

Vibration eg from pilingVibration eg from piling

Objectives

By the end of this lecture you should be able to:• Understand the properties of sound.• Identify the various noise problems that

arise in buildings. Understand how reflection, absorption and reverberation affect room acoustics.

• Understand how good sound insulation can be achieved.

• Be aware of the requirements of Building Regulations Part E.

What is sound?What is sound?

A disturbance in the atmosphereA disturbance in the atmosphereTravels in three dimensionsTravels in three dimensionsPressure fluctuations are smallPressure fluctuations are smallSound is measured in pascals (Pa); 1 Sound is measured in pascals (Pa); 1 pascal is equivalent to 1 newton per pascal is equivalent to 1 newton per square metresquare metreNormal atmospheric pressure is about Normal atmospheric pressure is about 100,000 Pa100,000 PaA noisy environment may involve a sound A noisy environment may involve a sound pressure of about 1 Papressure of about 1 Pa

What is sound?What is sound?

Sound pressure is the deviation from Sound pressure is the deviation from atmospheric pressure due to the passage atmospheric pressure due to the passage of a sound waveof a sound waveA 1% fluctuation is caused by a very loud A 1% fluctuation is caused by a very loud sound indeed.sound indeed.For comparison, normal weather variations For comparison, normal weather variations may cause a pressure change of 3,000Pa may cause a pressure change of 3,000Pa or 3% in the course of a day or 3% in the course of a day Noise is the same as soundNoise is the same as soundIt is normally called noise if it is unwantedIt is normally called noise if it is unwanted

Sound wavesSound waves

Are longitudinal wavesAre longitudinal wavesie the chunks of air move backwards ie the chunks of air move backwards and forwards in the direction the and forwards in the direction the wave travelswave travelsThis is very difficult to drawThis is very difficult to drawSo in practice they are often So in practice they are often represented as graphs of pressure represented as graphs of pressure against either time or distanceagainst either time or distance

Frequency and wavelengthFrequency and wavelength

The frequency of a The frequency of a wave is the wave is the number of waves number of waves arriving at a fixed arriving at a fixed point in one second point in one second Normal symbol fNormal symbol fThe unit of The unit of frequency is the frequency is the hertz (formerly the hertz (formerly the cycle per second)cycle per second)

The wavelength is the The wavelength is the length of one length of one complete cycle of the complete cycle of the wavewave

Normal symbol Normal symbol The unit of The unit of wavelength is the wavelength is the metremetre

FrequencyFrequency

The human ear can hear sound with The human ear can hear sound with frequencies from 20 Hz to 20,000 Hzfrequencies from 20 Hz to 20,000 HzWe are most sensitive to the middle range, We are most sensitive to the middle range, particularly 1-3 kHzparticularly 1-3 kHzThese frequencies are also the most These frequencies are also the most damagingdamagingA system called A system called A weightingA weighting is used for is used for many measurements to approximate many measurements to approximate human hearinghuman hearing

If you multiply the frequency of any wave If you multiply the frequency of any wave by the wavelength, you get its velocityby the wavelength, you get its velocityThe velocity of sound in air varies with The velocity of sound in air varies with temperaturetemperatureAt “normal” temperatures it is about 340 At “normal” temperatures it is about 340 msms-1-1

So frequency can easily be converted to So frequency can easily be converted to wavelengthwavelength and vice versaand vice versaAudible wavelengths are from Audible wavelengths are from a few a few metres to a few millimetresmetres to a few millimetres

Velocity, frequency and Velocity, frequency and wavelengthwavelength

Wave propertiesWave properties

Sound waves demonstrate the Sound waves demonstrate the following properties, which are following properties, which are common to all waves;common to all waves;

RefractionRefraction

DiffractionDiffraction

ReflectionReflection

InterferenceInterference

RefractionRefraction

Waves bend when passing from one medium to Waves bend when passing from one medium to anotheranotherThey bend towards the normal if their velocity is They bend towards the normal if their velocity is greater in the greater in the second mediumsecond mediumWater looks Water looks shallower than shallower than it isit is

Air - higher speed

Water - lower speed

ObserverNormal

Actual depth

Apparent depth

Refraction of sound wavesRefraction of sound waves

The velocity of sound is different in layers The velocity of sound is different in layers of air at different temperaturesof air at different temperatures

Normally air temperature decreases with Normally air temperature decreases with height, and sound waves bend away from height, and sound waves bend away from the groundthe ground

A temperature inversion causes them to A temperature inversion causes them to bend towards the ground. Sound is the bend towards the ground. Sound is the audible at much greater distances.audible at much greater distances.

DiffractionDiffraction

The tendency of waves to bend round cornersThe tendency of waves to bend round cornersMore pronounced at long wavelengthsMore pronounced at long wavelengthsNot always obvious with light (but try Not always obvious with light (but try squinting at a sodium street light)squinting at a sodium street light)Sound waves have longer wavelengths and Sound waves have longer wavelengths and readily bend round cornersreadily bend round cornersSo you can hear a fire alarm in the corridorSo you can hear a fire alarm in the corridorOr someone talking about you in the next Or someone talking about you in the next roomroomLimits the effect of roadside noise barriersLimits the effect of roadside noise barriers

ReflectionReflection

Familiar in the case of light wavesFamiliar in the case of light wavesSurfaces may reflect in various ways;Surfaces may reflect in various ways;– Partial Partial – TotalTotal– SpecularSpecular– DiffuseDiffuse

Focusing by a concave mirrorFocusing by a concave mirror

Reflection of sound wavesReflection of sound waves

Noise levels increased if there is a hard Noise levels increased if there is a hard surface behind the sourcesurface behind the sourceA large building can make an aircraft A large building can make an aircraft appear to be in the opposite directionappear to be in the opposite directionSound levels in rooms a result of multiple Sound levels in rooms a result of multiple reflections from surfacesreflections from surfacesConcave surfaces can focus soundConcave surfaces can focus soundSurfaces may reflect different frequencies Surfaces may reflect different frequencies to different extentsto different extents

InterferenceInterference

Two sound waves can combine to set Two sound waves can combine to set up a pattern of standing wavesup a pattern of standing waves

Particularly at low frequenciesParticularly at low frequencies

This is the principle on which some This is the principle on which some musical instruments workmusical instruments work

It can cause problems in roomsIt can cause problems in rooms

The decibel scale?The decibel scale?

““Everyone” knows we measure sound Everyone” knows we measure sound levels in decibelslevels in decibelsFew people know much more about the Few people know much more about the scalescaleIt is based on logarithms, so It is based on logarithms, so calculations can be complicatedcalculations can be complicatedThe reasons for using this scale are not The reasons for using this scale are not very clearvery clearBut everyone else uses it, and…But everyone else uses it, and………you get nice numbers (0-100 you get nice numbers (0-100 ±½)±½)

Sound pressure levelSound pressure level

LLpp is the sound pressure level is the sound pressure level

Measured in decibelsMeasured in decibels

Some other quantities are measured in decibels Some other quantities are measured in decibels tootoo

LLpp is still sometimes called SPL is still sometimes called SPL

0

log20p

pLp

Addition of decibelsAddition of decibels

The decibel scale makes addition a bit The decibel scale makes addition a bit complicatedcomplicated

Suppose we measure the sound pressure level Suppose we measure the sound pressure level at a point with one source operating – Lat a point with one source operating – L11

Then we switch off the first source, switch on a Then we switch off the first source, switch on a different one and measure the sound pressure different one and measure the sound pressure level at the same reception point – Llevel at the same reception point – L22

What sound pressure level LWhat sound pressure level Lpp would be would be

measured at that point if both sources operated?measured at that point if both sources operated?

Graphical additionGraphical addition

0

0.5

1

1.5

2

2.5

3

0 1

2 3

4 5

6 7

8 9

10 11

12 13

14 15

16 17

18 19

20

Addition of Decibels

Difference in levels/dB

dB to be added to higher level

Graphical addition - exampleGraphical addition - example

0

0.5

1

1.5

2

2.5

3

0 1

2 3

4 5

6 7

8 9

10 11

12 13

14 15

16 17

18 19

20

Addition of Decibels

Difference in levels/dB

dB to be added to higher level

Two noise sources individually cause Lps of 86 and 88 dB at a point. What Lp will result from both sources simultaneously?

88-86 = 2dBAdd 2 dB to the higher level; 88 = 2 = 90 dB

Simple addition of decibelsSimple addition of decibels

We have a noise source operating and the We have a noise source operating and the meter reads 80 dBmeter reads 80 dB

If we add an identical noise source at the If we add an identical noise source at the same position, the meter reading will go same position, the meter reading will go up to 83 dBup to 83 dB

In general, In general, – Doubling the noise sources adds 3 dB to LDoubling the noise sources adds 3 dB to Lpp

– Halving the sources reduces LHalving the sources reduces Lpp by 3 dB by 3 dB

Sound power levelSound power level

The sound power level The sound power level (L(LWW) is a measure of ) is a measure of

the noise emitted by a the noise emitted by a sourcesource

NotNot the same as the same as sound pressure levelsound pressure level

Often labelled on Often labelled on outdoor equipmentoutdoor equipment

Can be used to make Can be used to make LLp p predictionspredictions

Point sourcesPoint sources

Small compared with their distanceSmall compared with their distance

In the free field, sound levels fall by 6 dB every In the free field, sound levels fall by 6 dB every time you double the distancetime you double the distance

Line Line sourcessourcesExtended in one Extended in one dimensiondimension

In the free field, In the free field, sound levels fall by sound levels fall by 3 dB every time 3 dB every time you double the you double the distancedistance

Prediction of sound levelsPrediction of sound levels

Radiated from a point source outdoorsRadiated from a point source outdoors

Radiated from a point source outdoorsRadiated from a point source outdoors

Indoors, there are multiple reflections from Indoors, there are multiple reflections from surfaces and predictions are more surfaces and predictions are more complicatedcomplicated

Lp = LW - 20logr -11

Lp = LW -10logr - 8

Acoustics in buildingsAcoustics in buildings

Sound insulation - between roomsSound insulation - between roomsSound absorption - within a roomSound absorption - within a room

The two ideas are often confused by non-The two ideas are often confused by non-specialistsspecialistsParticularly in complex structures (eg Particularly in complex structures (eg partition walls), the absorption and partition walls), the absorption and insulation work together to control noise insulation work together to control noise

Sound absorptionSound absorption

Panel materials (absorb at low frequencies)Panel materials (absorb at low frequencies)– eg plasterboard wallseg plasterboard walls

Porous materials (absorb at high Porous materials (absorb at high frequencies)frequencies)– Stability of porous surfaces is a problemStability of porous surfaces is a problem

Traditionally absorption comes mainly from Traditionally absorption comes mainly from suspended ceilingssuspended ceilingsCombination absorbers can be “tuned” to Combination absorbers can be “tuned” to requirements across the frequency rangerequirements across the frequency range

ReverberationReverberation

Reverberation time (RT) is a measure of Reverberation time (RT) is a measure of how long it takes sound to die awayhow long it takes sound to die away

It is the simplest measure of acoustic It is the simplest measure of acoustic conditions inside a roomconditions inside a room

Sound absorbing surfaces tend to reduce Sound absorbing surfaces tend to reduce the RTthe RT

Reflective surfaces tend to increase itReflective surfaces tend to increase it

Reverberation timesReverberation times

Rooms for speech should have an RT less Rooms for speech should have an RT less than 1s (<0.8s required for school than 1s (<0.8s required for school classrooms)classrooms)

For music the RT should be longer For music the RT should be longer (depends on the type of music)(depends on the type of music)

Long RTs reduce speech intelligibilityLong RTs reduce speech intelligibility

Very short RTs stop sound propagating Very short RTs stop sound propagating around the roomaround the room

Reverberation timesReverberation timesRooms for speech should have an RT less than 1s (<0.8s required Rooms for speech should have an RT less than 1s (<0.8s required for school classrooms)for school classrooms)For music the RT should be longer (depends on the type)For music the RT should be longer (depends on the type)Long RTs reduce speech intelligibilityLong RTs reduce speech intelligibilityVery short RTs stop sound propagation around the roomVery short RTs stop sound propagation around the room

Reverberation timesReverberation timesRooms for speech should have an RT less than 1s (<0.8s required Rooms for speech should have an RT less than 1s (<0.8s required for school classrooms)for school classrooms)For music the RT should be longer (depends on the type)For music the RT should be longer (depends on the type)Long RTs reduce speech intelligibilityLong RTs reduce speech intelligibilityVery short RTs stop sound propagation around the roomVery short RTs stop sound propagation around the room

Sound insulationSound insulation

Traditionally insulation was Traditionally insulation was achieved by high surface mass achieved by high surface mass and high integrityand high integrityThere is a move from masonry There is a move from masonry walls towards lightweight walls towards lightweight structuresstructuresCombining sound insulation and Combining sound insulation and sound absorption principles sound absorption principles means lightweight structures means lightweight structures can perform better than masonry can perform better than masonry structuresstructures

Sound insulationSound insulation

Laboratory Laboratory measurementsmeasurements

Field measurementsField measurements

Two common quantitiesTwo common quantities

RRww

Weighted sound Weighted sound reduction indexreduction index

Measured in a Measured in a laboratorylaboratory

Relates to a particular Relates to a particular material or productmaterial or product

DDnT,wnT,w

Weighted, Weighted, standardised level standardised level differencedifference

Measured in a real Measured in a real buildingbuilding

Used to specify Used to specify building performancebuilding performance

The difference between RThe difference between Rww and and

DDnT,w nT,w depends ondepends on

Room shape and sizeRoom shape and size

Weak spots where two building elements Weak spots where two building elements joinjoin

Workmanship issuesWorkmanship issues

Flanking transmissionFlanking transmission

Sound insulationSound insulation

Often the sound insulation is decided by Often the sound insulation is decided by the weak component in a partition. This the weak component in a partition. This may be; may be; – There by design (eg a door)There by design (eg a door)– Due to faulty design or workmanship (eg a Due to faulty design or workmanship (eg a

continuous cavity above a suspended ceiling)continuous cavity above a suspended ceiling)– Difficult to avoid (eg ventilation ducts)Difficult to avoid (eg ventilation ducts)

Air leakage paths – an illustrationAir leakage paths – an illustration

Air leakage paths – an illustrationAir leakage paths – an illustration

50

40

45

Building Regs

Good walls

Improved

Original

Sound insulation in decibels

Air leakage pathsAir leakage paths

Effect of small air gaps on the overall sound insulation performance of a 3.0 metre high wall

20.0

25.0

30.0

35.0

40.0

45.0

50.0

Air gap in millimetres

Ove

rall

soun

d re

duct

ion

inde

x Rw=25dB

Rw=30dB

Rw=40dB

Rw=50dB

Flanking transmissionFlanking transmission

Direct sound

Flanking Flanking transmissiontransmission

Flanking paths become important once the Flanking paths become important once the direct sound has been reduceddirect sound has been reducedMay need to introduce structure breaks etcMay need to introduce structure breaks etcA continuous floor slab (as shown) would A continuous floor slab (as shown) would not be allowed for party wallsnot be allowed for party walls

Direct sound

Improving sound insulationImproving sound insulation

Increasing sound insulation performance

Increase mass

Reduce flanking

Eliminate gaps

Sound insulation - door Sound insulation - door considerationsconsiderations

A door plus frame will typically be rated at A door plus frame will typically be rated at about 28 dB of sound insulationabout 28 dB of sound insulation

If it takes up 10% of the surface area, then If it takes up 10% of the surface area, then however good the wall system the however good the wall system the maximum sound insulation is 38 dB.maximum sound insulation is 38 dB.

This assumes perfect installationThis assumes perfect installation

Doors should Doors should nevernever be installed between be installed between occupied roomsoccupied rooms

Sound insulation is dead simpleSound insulation is dead simple

L´nT,w

DnTRw

DnT,wDw

R´w

Ctr

Dn,e

DnT,w+ Ctr

D2m,n

Rtr,s

- not

Part EPart E

The Building ActThe Building Act

The Building Regulations 2000, as The Building Regulations 2000, as amended in 2002amended in 2002

Approved Document E - 2003 editionApproved Document E - 2003 edition

The law applying in Scotland is differentThe law applying in Scotland is different

PurposePurpose

“…“…securing reasonable standards of health securing reasonable standards of health and safety …(and welfare and and safety …(and welfare and convenience) …for persons in and about convenience) …for persons in and about the building.”the building.”

(Other regulations include energy (Other regulations include energy conservation and prevention of water conservation and prevention of water contamination in their purposes)contamination in their purposes)

Regulation E1 Regulation E1 (2002 version)(2002 version)

Dwelling-houses, flats and rooms for Dwelling-houses, flats and rooms for residential purposes shall be designed and residential purposes shall be designed and constructed in such a way that they constructed in such a way that they provide reasonable resistance to sound provide reasonable resistance to sound from other parts of the same building and from other parts of the same building and from adjoining buildings.from adjoining buildings.

Regulation E2 Regulation E2 (2002 version)(2002 version)

Dwelling-houses, flats and rooms for Dwelling-houses, flats and rooms for residential purposes shall be designed residential purposes shall be designed and constructed in such a way thatand constructed in such a way that

(a)(a) internal walls between a bedroom or a internal walls between a bedroom or a room containing a water closet , and room containing a water closet , and other rooms, andother rooms, and

(b)(b) Internal floors,Internal floors,Provide reasonable resistance to sound.Provide reasonable resistance to sound.

Regulation E3 Regulation E3 (2002 version)(2002 version)

The common internal parts of buildings The common internal parts of buildings which contain flats or rooms for residential which contain flats or rooms for residential purposes shall be designed and purposes shall be designed and constructed in such a way as to prevent constructed in such a way as to prevent more reverberation around the common more reverberation around the common parts than is reasonableparts than is reasonable

Regulation E4 Regulation E4 (2002 version)(2002 version)

(1)(1) Each room or space in a school building shall Each room or space in a school building shall be designed and constructed in such a way be designed and constructed in such a way that it has the acoustic conditions , and the that it has the acoustic conditions , and the insulation against disturbance by noise insulation against disturbance by noise appropriate to its intended use.appropriate to its intended use.

(2)(2) For the purpose of this part – “school” – has For the purpose of this part – “school” – has then same meaning as in section 4 of the then same meaning as in section 4 of the Education act 1996, and “school building” Education act 1996, and “school building” means any building forming a school or part of means any building forming a school or part of a school.a school.

Buildings and Buildings and structures structures coveredcovered

Residential buildings Residential buildings SchoolsSchoolsParty walls Party walls (airborne sound)(airborne sound)

Party floors and stairsParty floors and stairs(airborne and impact (airborne and impact

sound)sound)

Some internal wallsSome internal wallsCommon areasCommon areas

Hospitals, offices, Hospitals, offices, prisonsprisonsMost internal walls Most internal walls within a dwellingwithin a dwellingExternal wallsExternal walls

Buildings and Buildings and structures not structures not

coveredcovered

Ways of complying with the Ways of complying with the Regulation – converted Regulation – converted

buildingsbuildings

Test 10% of party walls and floor as Test 10% of party walls and floor as they are completedthey are completed

Internal walls and reverberation in Internal walls and reverberation in common areas are approved on the common areas are approved on the basis of the plans submitted (no testing)basis of the plans submitted (no testing)

Ways of complying with the Ways of complying with the Regulation – New buildingsRegulation – New buildings

Test 10% of party walls and floor as Test 10% of party walls and floor as they are completedthey are completed

OrOrUse Robust DetailsUse Robust Details

Internal walls and reverberation in Internal walls and reverberation in common areas are approved on the common areas are approved on the basis of the plans submitted (no testing)basis of the plans submitted (no testing)

Ways of complying with the Ways of complying with the Regulation – School buildingsRegulation – School buildings

Submit plans to the building inspector Submit plans to the building inspector showing how the requirements are to showing how the requirements are to be met. They are approved on the be met. They are approved on the basis of the plans submitted (no basis of the plans submitted (no testing)testing)

Standards for sound insulation – Standards for sound insulation – new buildingsnew buildings

Airborne DAirborne DnT,wnT,w+ C+ Ctrtr ≥ 45 dB for walls and ≥ 45 dB for walls and floors in flats and housesfloors in flats and houses

Airborne DAirborne DnT,wnT,w+ C+ Ctrtr ≥ 45 dB for floors in ≥ 45 dB for floors in rooms for residential purposesrooms for residential purposes

Airborne DAirborne DnT,wnT,w+ C+ Ctrtr ≥ 43 dB for walls in ≥ 43 dB for walls in rooms for residential purposesrooms for residential purposes

Impact LImpact LnT,wnT,w≤ 62 dB in flats, houses and ≤ 62 dB in flats, houses and rooms for residential purposesrooms for residential purposes

Standards for sound insulation – Standards for sound insulation – converted buildingsconverted buildings

Airborne DAirborne DnT,wnT,w+ C+ Ctrtr ≥ 43 dB for walls and ≥ 43 dB for walls and floors in flats and housesfloors in flats and houses

Airborne DAirborne DnT,wnT,w+ C+ Ctrtr ≥ 43 dB for floors in ≥ 43 dB for floors in rooms for residential purposesrooms for residential purposes

Airborne DAirborne DnT,wnT,w+ C+ Ctrtr ≥ 43 dB for walls in ≥ 43 dB for walls in rooms for residential purposesrooms for residential purposes

Impact LImpact LnT,wnT,w≤ 64 dB in flats, houses and ≤ 64 dB in flats, houses and rooms for residential purposesrooms for residential purposes

Standards for sound insulation – Standards for sound insulation – internal walls and floorsinternal walls and floors

RRww ≥ 40 dB in each case≥ 40 dB in each case

Reverberation standardsReverberation standards

Cover an area equal to the floor area with an Cover an area equal to the floor area with an absorbing material meeting absorption class D absorbing material meeting absorption class D or betteror betterOr 50% of the floor area with an absorber Or 50% of the floor area with an absorber meeting absorption class C or bettermeeting absorption class C or better

OrOrMake sure that from 250 Hz to 4 kHz the Make sure that from 250 Hz to 4 kHz the absorption area is at least 0.2 mabsorption area is at least 0.2 m22 per cubic per cubic metre (for entrances) or at least 0.25 mmetre (for entrances) or at least 0.25 m22 per per cubic metre (for corridors or hallways) cubic metre (for corridors or hallways)

ConversionsConversions

In the case of a In the case of a historic buildinghistoric building it may not it may not be practical to meet the required standards be practical to meet the required standards within the requirements of the listed Building within the requirements of the listed Building RegulationsRegulations

In this case it may be agreed that the sound In this case it may be agreed that the sound insulation performance is measured and is insulation performance is measured and is then declared via a notice fixed to the building then declared via a notice fixed to the building in a conspicuous place.in a conspicuous place.

BB93 requirements for school BB93 requirements for school buildings - sound insulation buildings - sound insulation

between roomsbetween rooms

Rooms are divided (table 1.1) into Rooms are divided (table 1.1) into categories according to categories according to – how much noise they generatehow much noise they generate– How sensitive they are to noiseHow sensitive they are to noise

Sound insulation is specified as DSound insulation is specified as DnT,wnT,w

A value of DA value of DnT,wnT,w is specified for each pair of is specified for each pair of

rooms - table 1.2rooms - table 1.2

BB93 DBB93 DnT,wnT,w requirements requirements

Classroom - classroomClassroom - classroom 45 dB45 dB

Music room – music roomMusic room – music room 55 dB55 dB

Hall – drama studioHall – drama studio 55 dB55 dB

Between open-plan teaching Between open-plan teaching areasareas

40 dB40 dB

Sound insulation between Sound insulation between rooms and circulation areasrooms and circulation areas

Very difficult to measure, so this is Very difficult to measure, so this is specified in terms of Rspecified in terms of Rww (ie manufacturer’s (ie manufacturer’s

data)data)

Two specifications - music rooms and Two specifications - music rooms and everywhere elseeverywhere else

Normally determined by the size and Normally determined by the size and specification of the doorspecification of the door

Robust DetailsRobust Details

The Robust Details are contained in a The Robust Details are contained in a manual published by Robust Details Ltdmanual published by Robust Details Ltd

Plot must be registered with Robust Plot must be registered with Robust Details in advanceDetails in advance

RD inspectors can check on the workRD inspectors can check on the work

Sample testing to monitor each RDSample testing to monitor each RD

No completion testing on each No completion testing on each developmentdevelopment

Robust details exist forRobust details exist for

WallsWalls– Masonry Masonry – SteelSteel– TimberTimber

FloorsFloors– ConcreteConcrete– TimberTimber– Steel-concrete compositeSteel-concrete composite

Robust DetailsRobust Details

Detailed requirementsDetailed requirements

Particularly for junctionsParticularly for junctions

Use generic materials Use generic materials – In theoryIn theory

Specifications include density etcSpecifications include density etc

ChecklistsChecklists

Example – masonry wallsExample – masonry wallsSeparating walls - masonrySeparating walls - masonry

E-WM-1E-WM-1 Masonry - dense aggregate blockwork (wet plaster)Masonry - dense aggregate blockwork (wet plaster)

E-WM-2E-WM-2 Masonry - lightweight aggregate blockwork (wet plaster)Masonry - lightweight aggregate blockwork (wet plaster)

E-WM-3E-WM-3 Masonry - dense aggregate blockwork (render and gypsum-based Masonry - dense aggregate blockwork (render and gypsum-based board)board)

E-WM-4E-WM-4 Masonry - lightweight aggregate blockwork (render and  gypsum-based Masonry - lightweight aggregate blockwork (render and  gypsum-based board)board)

E-WM-5E-WM-5 Masonry - Besblock "Star Performer" cellular blockwork (render and Masonry - Besblock "Star Performer" cellular blockwork (render and gypsum-based board)gypsum-based board)

E-WM-6E-WM-6 Masonry - aircrete blockwork (render and gypsum-based board)Masonry - aircrete blockwork (render and gypsum-based board)

E-WM-7E-WM-7 Not Currently AvailableNot Currently Available

E-WM-8E-WM-8 Masonry - lightweight aggregate blockwork British-Gypsum-Isover Masonry - lightweight aggregate blockwork British-Gypsum-Isover ISOWOOL (gypsum-based board)ISOWOOL (gypsum-based board)

Robust Details problemsRobust Details problems

ChecklistsChecklists

Some bad failuresSome bad failures

Detailing – recent advice on mortar in Detailing – recent advice on mortar in cavity wallscavity walls

Problems with the Building Problems with the Building RegulationsRegulations

Was the move from DWas the move from DnT,wnT,w to frequency to frequency noise) Dnoise) DnT,wnT,w+ C+ Ctrtr justified? justified?

Is Regulation E too limited in scope?Is Regulation E too limited in scope?Do they discourage the development of Do they discourage the development of new materials and techniques which new materials and techniques which provide higher levels of sound insulation?provide higher levels of sound insulation?Do Building Inspectors have the Do Building Inspectors have the necessary specialist expertise?necessary specialist expertise?

Further informationFurther information

Approved Document E. HMSO, 2003Approved Document E. HMSO, 2003

Resistance to the Passage of SoundResistance to the Passage of Sound

http://www.planningportal.gov.uk/uploads/http://www.planningportal.gov.uk/uploads/br/BR_PDF_ADE_2003.pdfbr/BR_PDF_ADE_2003.pdf

DfES (2003). BB93; Acoustic Design of DfES (2003). BB93; Acoustic Design of Schools TSO Schools TSO

Smith, Peters and Owen (1996) Acoustics Smith, Peters and Owen (1996) Acoustics and Noise Control 2and Noise Control 2ndnd Edition. Longman Edition. Longman