Sound insulation Sound insulation with Geberit system technology

Table of Contents

Contents

1 1.1 1.1.1 1.1.2 1.1.3 1.2 1.2.1 1.2.2 1.3 1.3.1 1.3.2 1.3.3 1.3.4 1.3.5 1.3.6 1.3.7 1.3.8 1.3.9 1.3.10 1.3.11 1.3.12 1.3.13

Basics Sound measurement and loudness Sound pressure level Perceiving loudness Multiple sound sources Sound insulation in buildings Airborne and structure-borne sound Sound reduction index Sound insulation in sanitary technology Keep quiet areas far away Wall-hung WC Optimised wall-hung frame Insulation tape Sound insulation pad Pipe bracket with sound insulation Stack without direction change Quiet pipes Insulation mats Jointing method Prewall protection Sound measurements at Geberit Any further questions?

2 2.1 2.2 2.2.1

Sound measurements General Test results Measurement results with different setups

10 10 10 10

3 3.1 3.2 3.3

Sound insulation setups Geberit drainage with floor standing WC on wooden furniture Geberit drainage with wall-hung WC in timber stud prewall Geberit drainage with back-to-back wall-hung WCs in full height metal studs

11 11 12 13

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1 Basics

1 Basics

1.1 Sound measurement and loudness Sound moves through the air in waves. When a sound wave reaches our ear, we perceive its pressure as a certain loudness and its frequency as a certain pitch. The higher the sound, the higher the frequency, and the louder the sound, the greater the acoustic pressure.

dB(A) 140 130 120 110

p

100 90

λ Figure 1:

80 70

Tuning fork with sound wave

The height of the sound wave corresponds to the sound pressure p. The number of oscillations per unit of time corresponds to the frequency f, which is calculated using the wavelength λ and the speed of sound c:

60 50 40 30

Our ears do not have the ability to perceive the full range of sound pressure and frequency levels. Generally speaking, they are able to pick up sound waves within the following limits (referred to as thresholds of audibility). • Sound pressure: 20 μPa to 20 Pa • Frequency: 20 Hz to 20 kHz

20 10 0

Figure 2:

1.1.1 Sound pressure level Given that sound pressure covers an extensive range of values, it is usually the sound pressure level Lp that is measured. This is defined as follows:

Here, the sound pressure p0 is defined as 20 μPa, which means that 0 dB (decibels) correspond to exactly p0, the lower threshold of audibility. As such, the thresholds of audibility are as follows: • sound pressure level: 0–120 dB

4

Sound pressure levels of different sound sources

1.1.2 Perceiving loudness Our hearing is at its most sensitive at a frequency of 1–5 kHz and, within this range, is able to perceive sounds with a lower acoustic pressure level of 0 dB. In other frequency ranges, however, sounds do not become audible until they reach approximately 20 dB. By definition, the sound pressure level measured in decibels and the loudness measured in phons are the same when a 1000 Hz sound is present.

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1.1.3 Multiple sound sources

100

100

80

80 60

60

40

40

20

20

20,000

10,000

5,000

2,000

1,000

500

3 200

100

50

Threshold of 0 audibility 20

Sound pressure eve [dB]

1 Basics

If multiple sound sources are present at the same time, something more than a simple addition calculation is needed to calculate the total sound pressure level. Instead, energetic addition must be used. Let's say that the ticking of a clock, the sound of pipes in the building, and traffic noise are all happening at once during the night. In this case, we would carry out the following calculation: • clock ticking: 20 dB(A) • night-time quiescent level: 26 dB(A) • sound of pipes in the building: 28 dB(A) • traffic noise: 30 dB(A)

Frequency [Hz] Figure 3:

Curves representing the same loudness

As an example, a sound measuring 60 Hz requires a sound pressure level of 60 dB in order to be perceived as having the same level of loudness as a sound measuring 1000 Hz and 40 dB. Frequency filters are used to simulate this perception of loudness. In the case of measuring instruments, this normally takes the form of an A-weighting filter, which reduces the instrument's sensitivity at low sounds. The measured values are specified in dB(A).

,

,

,

,

0 dB + 0 dB = 3 dB The total sound pressure level for two sound sources at 0 dB each is calculated as follows:

A sound pressure level of 0 dB does not mean that no sound pressure is present. By definition, 0 dB correspond to 20 μPa.

0 -10 -20 -30 -40

Figure 4:

16,000

Frequency [Hz]

8,000

4,000

2,000

1,000

500

250

125

63

-60

31 5

-50 16

Re at ve sens t v ty [dB]

10

,

A-weighted sound pressure level

At a frequency of 100 Hz, for example, the measured sound pressure level is reduced by 19 dB from 70 dB, meaning that 70 dB correspond to 51 dB(A).

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1 Basics

1.2 Sound insulation in buildings 1.2.1 Airborne and structure-borne sound Sound is transmitted both through the air and by means of wall and ceiling vibrations. In the latter case, we refer to structure-borne sound.

Figure 5:

1.2.2 Sound reduction index Sound insulation is measured using the sound reduction index R’W, which specifies the difference between the sound pressure levels in two rooms. If the transmitted sound measures 50 dB and the received sound in the adjacent room measures 20 dB, this equates to a sound reduction index of 30 dB (corrected by a factor reflecting the absorption capacity of the adjacent room). The sound reduction index R’W also takes into account the flanking transmission; in other words, the transmission of sound through adjacent components.

Airborne sound propagation

1

1 Figure 6:

Structure-borne sound propagation

Encapsulation can reduce the extent to which airborne sound is transmitted; in this case, components are enclosed in sound-insulating product materials.

Figure 9: 1 2

2

2

Sound transmission with flanking transmission

Direct sound transmission Flanking transmission

The sound reduction index of walls and ceilings chiefly depends on their dimensions and bending strength. The larger a wall is, the higher its sound reduction index. The following values apply in this case: Figure 7:

Airborne sound insulation

To prevent structure-borne sound propagation, the individual components must be kept apart from one another. Elastic connections or insulating layers may be used for sound insulation purposes.

Wall product material

Brick with lime plaster (15 mm) Concrete, raw and pore-tight Panels

Thickness [cm]

Basis weight [kg/m2]

Sound reduction index RW [dB]

24

366

53

7

170

42

8

70

35

1

Figure 8: 1

Structure-borne sound insulation

Elastic insulating layer

Structure-borne sound insulation must cover the entire area, as even a single sound bridge can negate its effect altogether.

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1 Basics

1.3 Sound insulation in sanitary technology

The following fundamental principles should be applied in order to ensure adequate sound insulation.

1.3.1 Keep quiet areas far away Installation walls should not border areas that are intended to be quiet, such as bedrooms.

1.3.3 Optimised wall-hung frame By designing in a Geberit Duofix frame you have already optimised your acoustic values. Integrated rubber tipped push rods to reduce noise from the flush plate when pressed for flushing, a polythene jacket insulating the cistern, circlips on threaded rods to eliminate movement and sound absorbing seals on drainage brackets - Geberit Duofix frames have it covered.

1

Figure 11:

Geberit Duofix frame for wall-hung WC, H112, with Sigma cistern 12cm (Article no. 111.383.00.5)

1.3.4 Insulation tape Duofix insulation tape for structure-bourne sound minimisation between panels, system rails and building structures.

2

Figure 10: 1 2

Optimum ground plan layout

Installation wall next to stairs Installation wall next to quiet area

Figure 12:

Geberit Duofix insulation tape (Article no. 111.889.00.5)

1.3.2 Wall-hung WC When choosing a WC always look to wall mount to decouple from the floor.

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1 Basics

1.3.5 Sound insulation pad

1.3.7 Stack without direction change

When installing a WC, always use a sound insulation mat as well as sound insulation sleeves for the fastening screws.

Where possible, do not incorporate direction changes into stacks. Straight stacks have a lower effect on acoustic insulation.

1 2

Figure 16: Figure 13: 1 2

WC with Geberit sound insulation set

Sound insulation mat Sound insulation sleeve for fastening screw

Optimum stack

If direction changes are unavoidable, however, take care to ensure that the angles of the resulting diversions are as small as possible.

1.3.8 Quiet pipes Use quiet pipes such as Geberit Silent-db20.

Figure 14:

Geberit acoustic insulation set for wall-hung WC and wall-hung bidet (Article no. 156.050.00.1)

1.3.6 Pipe bracket with sound insulation Always choose pipe brackets with rubber lining and make sure they are not tightened too firmly. Never use cement for fastening components to the wall, as this could result in sound bridges. By selecting Geberit pipe brackets with the appropriate diameter and tightening them fully, it is possible to achieve optimum fastening and sound insulation conditions.

Figure 15:

8

Geberit Pipe bracket with acoustic insulation d56-160 (Article no. 3xx.812.26.1 and 315.813.26.1 for diameter 178 (diameter 160 double sleeve coupling))

Figure 17:

Geberit Silent-db20 sound insulating branch fitting

Geberit Silent-Geberit Silent-db20 is highly sound optimised and satisfies numerous requirements with mineral reinforced polyethylene for a denser material and fittings to dissipate noise at impact zones, Geberit Silent-db20 adds value to any installation.

Figure 18:

Geberit Silent-db20 pipe, length 3.0 m, d56-160 (Article no. 30x.000.14.1)

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1 Basics

1.3.9 Insulation mats Wraps pipes and fittings to reduce airborne sound spreading

Figure 19:

Geberit sound insulation mat ISOL Flex (Article no. 356.01x.00.1)

1.3.10 Jointing method Electrofusion couplings maintain a smooth internal bore thus reducing noise transfer.

Figure 20:

1.3.12 Sound measurements at Geberit Geberit has performed sound measurements under realistic conditions in a laboratory set up specifically for this purpose. These have produced reliable measurement results for building owners and designers. The measurement results can be found on the pages that follow. Please note that the specified sound pressure levels apply to the construction situations mentioned in each case and may only be of limited relevance to other construction situations.

1.3.13 Any further questions? Contact your experts at Geberit: www.geberit.co.uk

Geberit HDPE electrofusion coupling d40-160 (Article no. 36x.771.16.1)

1.3.11 Prewall protection A lightweight prewall has a significant effect on sound insulation. This kind of structure can also be given additional sound-absorbing properties using a thin foam layer facing the floor or ceiling.

m1

m2

Prewall

Figure 21:

Structure of prewall installation

The larger the ratio in mass per unit area between the prewall (m1) and the wall (m2), the better the joint insulation will be.

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2 Sound measurements

2 Sound measurements

2.1 General

2.2 Test results

All test installations were designed in the UK and the measurements conducted by Geberit in their own sound laboratories. By installing the complete Geberit system we are able to take test measurements from real UK scenarios and measure the results from three different adjoining rooms. The acoustics from a bathroom are not solely dependent on the drainage pipe, and as such testing the complete system inclusive of cistern, WC, wall structure AND drainage is far more meaningful in the real world.

On the following pages, the Geberit test results are given meaning through diagram rated sound classifications. The functional requirement in the UK is considered satisfied when 44 dB in the living room has been met. However research in the UK by Geberit Sales Ltd has shown that in high end residential and luxury hotels, clients and specifiers alike are looking to achieve 25 dB within the bedroom Classification

LAFmax,n [dB(A)]

Acoustic rating

Class A +

A+

20

20 db

Class A

A

25

25 db

Class B

B

30

30 db

Class C

C

35

35 db

Class D

D

40

40 db

Class E

E

45

45 db

LAFmax,n: the mean maximum sound pressure level

2.2.1 Measurement results with different setups Measurements, status 09.09.2015

Room 1 Installation Room Room 2 Room 3

• • Measurement • •

Timber stud walls 15 mm plasterboard Furniture BTW WC Geberit Silent-db20

• • • • •

Timber stud walls 15 mm plasterboard Timber prewall Wall-hung WC Geberit Silent-db20

• • • •

Geberit Duofix metal stud walls 15 mm plasterboard Wall-hung WC back-to-back Geberit Silent-db20

Horizontal Room 1

30 db

B

30 db

B

35 db

C

Diagonal Room 2

30 db

B

25 db

A

25 db

A

Vertical Room 3

35 db

C

35 db

C

30 db

B

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3 Sound insulation setups

3 Sound insulation setups

3.1 Geberit drainage with floor standing WC on wooden furniture Building installation • Rear wall: 15 mm plasterboard each side with 75 x 38 mm timber studs mounted every 600 mm • Rear wall insulation: Gyproc SoundBloc 2 x 12.5mm mounted in between the plasterboard and studs • Mounted: Prefabricated wooden furniture cabinet • Insulation: Rockwool • Finish: Tiles Drainage pipes • Downpipe: Geberit Silent-db20 lagged • Horizontal drain pipe from WC: Geberit Silent-db20 unlagged • Horizontal drain pipes from washbasin: Geberi Silent-db20 unlagged • Fixings: Brackets mounted to wall

Room 1

Room 2

Sanitary products • Concealed cistern: Plastic