First of all, there are a few basic terms and definitions you should get acquainted with. Namely, building acoustics include two basic values, often mistaken for one another. Acoustic insulation refers to sound transmission reduction, that is certain insulation materials are used to stop or reduce the sound traveling from one place to another, thus decreasing the overall noise pollution. Now, the sound can either pass directly through a the element dividing two spaces (walls, floors etc) or through the surrounding structure, why we differ so called direct and indirect transmission. Another important difference is the one between airborne (the one transmitted through the air) and impact sound (caused by footsteps for example). The other component is sound absorption, which shows how much sound is absorbed and thus lost when interacting with a specific surface.
Now, some basics on the applicable regulation. The obligatory document regulating preferred levels of acoustic insulation in England is the Approved Document E of the Building Regulations, setting two basic methods of pre-determining whether a residential building meets the prescribed values – the so called Pre-Completion Testing and the Robust Details. While Pre-Completion Testing is always carried out by a specific test body which will determine whether a new construction fulfils the set values, Robust Details is a less complicated alternative which basically sets certain construction forms that have already been tested according to the standards set by Building Regulations. As for Scotland, the named documents do not apply, but the matter is regulated by Technical Handbook Section 5 with a few significant differences when compared to the rest of the UK.
The basic goal you want to achieve with soundproofing is to reduce the sound traveling from one room to another. This practically means that the materials you go for will depend on various factors that need to be previously consulted. This includes:
- determining the source of noise, that is does it come from the inside (from another room or the floor below, for instance) or does it come from the outside (traffic noise);
- determining the surface that is transmitting the noise (for example, is it your floor, wall, ceiling etc);
- determining the tolerable noise level (while consulting the previously mentioned regulation).
Now, sometimes the problem with noise you are dealing with can easily be taken care of if the level of noise is not too high and can be easily taken care of by simply placing a thicker wool rug (since wool is an excellent insulator) onto the floor or by hanging some heavy fabric curtains on your windows and doors.
At the same time, certain sources of noise cannot as easily be retained which implies that some extra measures of sound insulation must be taken. A very common approach is using some kind of barriers between the sound source and the rest of the space, like wall panels containing foam placed onto the interior wall, which can successfully absorb the noise, echoes and reverberations. Another option is filling the cavities inside the existing wall with some insulation material which will absorb some sound and stop it from entering the space next door, commonly used in residential and commercial buildings. Finally, if you want to be sure that your building meets the prescribed noise values, you can always go for some insulation materials especially designed for home acoustic insulation and soundproofing like rock mineral wool slabs which will not only regulate the noise level, but also affect the thermal performance of the building (so this ay you can kill two birds with one stone), by using plasterboards on drywall systems or by combining plasterboard walls and ceilings with some kind of protective coating like thin metal channels which will improve the sound quality of your home.