Musings of an Independent Chartered Building Surveyor, gathered over forty years of being in the Profession, and will be set down over the coming months. It will from time to time, provide information and endeavor to explain the intricacies of matters that affect the lives of Surveyors, the work they do and the legal and other regulations that is their working life.

The format suggested is based on the alphabet, if only to provide a structure to the musings etc, so this first week it will start at “A”, and possibly after a couple of months there may be a Questions section, if there is a demand, which will be developed and answered over the coming year. 

Acoustics

The world of acoustics has always been predominately in the world of Theatre and Concerts, where the sound, is so important to the audience, and if the sound is delayed outside its limits, the reflection from other surfaces can cause an echo. Wall and ceiling surfaces are designed to be hard [to reflect] and soft [to absorb] to produce the right conditions for the audience’s enjoyment.

Acoustics is now affecting everybody, the recent Building Regulations, Part E, the resistance to the path of sound. This latest legislation has brought sound reduction right to our doorstep. It is a science and mathematical, but I will try to cover it without involving them.

All new houses, alterations and extensions, are now checked during construction, for sound insulation, to ensure that sound does not adversely affect the owners, occupiers and our neighbours, be it airborne or impact sound, by reducing the sounds traveling from rooms and properties. You can loosely think of “sound” like “water” that leaks through gaps and holes in the construction of the house. In addition, the alteration required for “change of use” [to be explained later] from retail, i.e. flats above shops etc, to residential, must also have external road noise sound test. The Regulations set out the minimum performance requirements to limit noise. A booklet “Acoustic Performance Robust Details” has been published to illustrate the types of construction that meet the requirements without carrying out tests – existing properties require tests to meet the Regulations and these can be expensive.

There are basically two types of sound, Airborne sound is typically voices, music from TV’s and Hi-Fi systems, while Impact sound is from movement , foot fall across rooms, dropping things, flushing toilets, pipe work, washing machines and moving heavy items.

Sound is in wave form and the interruption of the waves is the method of insulation. The sound is measured in decibels, and is logarithmic, meaning that a doubling or halving of sound is registered as an increase or decrease of 10dB.

The insulation techniques include, having heavy construction i.e. concrete blocks in new buildings generally, absorbent linings to walls and within floors, absorbent floor sheets below carpets – some flat dwellers have been known to remove when changing the carpets – and sealants to ensure no gaps or holes.

Isolation of timbers in stud partition walls from the other face of the partition, so sound does not travel through the material. and an absorbent layer at the junction between stud  partition and floors. Seals to doors can also reduce sound through the doorway.

An example of sound reduction improvements in floors, of around 40 dB can be achieved with a specialist floor mat and carpet on a timber floor and a separate dropped ceiling below a timber joist floor can achieve around 10 dB reduction of noise intrusion.

The requirements detailed above are incorporated in all buildings, so in the future will lead to less stressful lives. 

I was brought up on a farm in Wales and I can remember going on holiday to Birmingham, country people go to town, and we stayed in a semi detached house, with back to back fire places, with coal fires, and the neighbours spent all evening poking their fire at regular intervals, it was a loud noise with only a half brick separating the two fireplaces, and was quite annoying.

Quoin   [a pseudonym for this article]
A RICS surveyor