Diagrams and Illustrations
Introduction
Page 6 – The four-step soundproofing method
PART ONE – You Deserve A Quiet Life
1 Is Your House Built To Make The Noise Worse?
Page 15 – Frequency Chart
PART TWO The Four-step Soundproofing Method For A Quiet Life
4 Step 1: Treat The Main Cause Of The Problem
Page 73 – Missing bricks around floor joists
Page 87 – Floor plan
5 Step 2: Treat The Direct Noise Paths
Page 95 – Material table
6 Step 3: Treat The Indirect Noise Paths
Page 116 – Upstairs bedroom noise. Adapted from Rindel, JH, Sound Insulation in Buildings (CRC Press, 2018)
Page 119 – Flanking noise through ceiling and suspended floors. Adapted from Rindel, JH, Sound Insulation in Buildings (CRC Press, 2018)
8 Are You Ready To Benefit From Soundproofing?
Page 157 – Noise in a downstairs room. Adapted from Rindel, JH, Sound Insulation in Buildings (CRC Press, 2018)
How is this possible?
Glossary
First Fix
A term used in the UK building and construction industry. ‘The first fix comprises all the work needed to take a building from foundation to putting plaster on the internal walls. This includes constructing walls, floors, and ceilings, and inserting cables for electrical
supply and pipes for water supply.’
https://en.wikipedia. org/wiki/First_fix_ and_second_fix
SAP
The government’s approved software for calculating the energy rating of your new property is called the Standard Assessment Procedure. Scores range from 1 to 100, with higher scores meaning lower energy consumption and CO2 levels. Scores over 100 mean that you are net producers of energy.
www.gov.uk/ guidance/standard- assessment- procedure
UKAS
The United Kingdom Accreditation Service is a national accreditation body recognised by the
British government to assess the competence of organisations that provide certification, testing, inspection and calibration services.
Appendix
Terms used in airborne sound-insulation testing
DnT
Standardised level difference
The single-number field measurement of the airborne
sound prevented from transmitting through a separating ceiling, wall or floor, expressed in decibels (dB). The higher the decibel figure, the better the sound insulation. If someone
is playing the drums in one room (100dB) and I measure 20dB in the adjoining room, the sound reduction is 80dB. The volume of the room together with the reverberation (echo) and amount of absorption in the room are all taken into account as part of the calculation.
DnT,w
Weighted DnT
DnT,w relates to an onsite test which picks up flanking noise, background noise and other elements such as the way the sound insulation was installed. Due to
the many variations that can arise on site, this figure will always be between 5dB and 8dB lower than Rw (see below) for a similar product or system.
DnT,w + Ctr
Weighted DnT + spectrum adaptation term
+ Ctr adjusts DnT,w figure by including a low-frequency correction factor. On site, there may be low-frequency background noise such as traffic noise (and other variations). The Ctr figure is always negative so DnT,w + Ctr will always be lower than DnT,w. If you live in Scotland, Ctr is not used and building regulations require DnT,w of 56dB
Dw
A term used to refer to onsite sound insulation. Simply, the measure of the source noise (eg acoustic drums) minus the measure of the noise of the drums outside the room.
LnT,w
Weighted, normalised impact sound pressure level
The field measurement used
to calculate the impact sound insulation of floors on site. If you are a developer, architect or builder renovating or changing the use of a separating floor or ceiling, you need to have an acoustic test to meet Part E of the Building Regulations, and you currently need the figure to be lower than 64dB to meet the required standards.
Rw
Weighted sound reduction index
The field measurement used
An acoustic test carried out
in a specialist acoustic testing laboratory, with no flanking
or background noise. Special instrumentation is used to ensure accuracy and repeatability of the test. The measurement is in decibels and it describes the airborne sound insulation of the building product
or system. Online products should quote Rw. Typically, Rw is 5–10dB higher (better) than DnT,w + Ctr.
Percentage Noise Reduction Example
A wall was tested before we started work and sound insulation was found to average 47dB. After sound- proofing, this same wall was tested and achieved a sound insulation value of 62dB. This is a 139.61% reduction in pressure level of sound from next door.
The calculation is as follows:
(A) 62dB = 0.0251785 Pa (pascals – measure of sound pressure)
(B) 47dB = 0.00447744 Pa
Change % = 100 × (A – B)/((A + B)/2)
= 100 × (0.0251785 – 0.00447744)/
((0.0251785 + 0.00447744)/2) = 100 × 0.0207/(0.02966/2)
= 100 × 1.39608
= 139.61%
THE NOISE FREE HOME
That gives a 139.61% change in pressure level of sound.
10db is a halving of sound as we hear it, so the 15dB reduction represents a significant reduction.
