…without getting arrested
We all have neighbours, whether they are miles away or sharing our party wall. They could be the perfect Mr and Mrs Smith or ‘the neighbours from hell’, but because sound travels through objects and around them, you may be troubled by their activities at some point in your life.
On a small Island like Guernsey, most of us live in close proximity to our neighbour and in densely populated areas, we may live above or alongside each other in closely formed Mews or multi-occupied premises. Whilst there is really nothing you can do about sound transferring from a neighbour enjoying the summer sunshine in their garden next door, you can take action to dampen sound coming through party walls or floor structures.
Sound transfers in two ways; by ‘impact’ and ‘air borne’. If we have a noisy neighbour we want to silence, then we need to know how their sound is getting to us. Once we have established this, we can take action accordingly.
Increase your mass
Airborne sound (talking, radios, TV’s) will travel through air but raised voices and loud TV’s will also travel through structures. The louder (more decibels) the noise, the easier the sound will pass through an object. If the object (party wall or floor structure) is wafer thin, then it won’t have the density to absorb the sound and reduce the sound transfer. Sound air waves travel and will only be stopped if they are absorbed; therefore the way to tackle noisy TV’s etc. is to increase your mass (or rather, that of your property).
Dense materials are normally used for this type of sound insulation. Insulation, plasterboard and even compacted sand is used to increase density in separating elements to reduce sound from travelling. It is important to think of sound behaving in much the same way water would behave; If the upstairs flat floods, water passes through any holes such as light fittings. The same happens for sound. Therefore any sound proofing materials used to increase density should ideally be without holes (any holes cut into the soundproofing material will automatically reduce the effectiveness of the sound proofing).
So what does this mean? Insulation, blocks and dense plasterboard or double layer plasterboard are needed in separating structures to reduce airborne sound. If you cut into these layers, you will reduce their ability to dampen sound. Therefore, don’t cuts holes for lights or cables which can allow the passage of air borne sound and increase the mass of separating walls or floors.
Reduce your impact
Sound also travels through objects by way of impact; as I type this Coffee Break, the vibrations on the keypad (although minor) will travel through the table, down the table leg and onwards. If I lift the table off the floor, the sound would reach the end of the table leg and stop. The sound would not travel any further or at least, only a small proportion would then go air borne.
To stop sound transferring through an object by way of impact, we need to separate the layers through which the impact sound is passing with ‘resilient layers’. Think of yourself walking over the floor of a flat. Each footstep causes vibration. The vibration passes through the flooring, the joists and the ceiling layer, allowing your neighbour below to hear every footstep. However, increasing density in this floor would not stop the vibrations or impact caused by each footstep. In this case, you would need to use a resilient layer such as a continuous rubber mat in between the floor structure and then your chosen floor covering. Again, no nail or screw fixings should pass through the mat because this will allow the sound to transfer. Think of resilient layers as a floating layer; it separates your footsteps from anything below, meaning vibrations will not pass through (or at least will be reduced).
We could also counter batten the underside of the floor joists with a special metal frame which would limit impact sound passing through the floor.
So, if you have a noisy neighbour above you, you could form a separating ceiling or a second ceiling layer which is not connected to the floor structure. Your neighbours could be bouncing around during Strictly Come Dancing and their vibrations would not pass through the floor because of the separation.
Out flank the flanking noise
Sound will travel around structures, meaning if the flats in a multi-storey building have their windows open, the sound will travel from one flat to the other simply though the open windows or doors, depending on wind direction. The sound could also reverberate, or bounce off other surfaces which you could reduce by applying absorbing materials to that surface. Sound studios use rubber or egg boxes on their walls to reduce sound reverberating off the wall surfaces. However, this is not usually an option for a private homeowner wanting to reduce flanking sound through a main wall. If your home has single pane windows, consider upgrading to double-glazing and keep the windows closed.
Some simple solutions to get you started
If you don’t want to go to the hassle and expense of applying things to your walls, ceilings and floors, try some simple interior methods instead and you may get the result you are after. You won’t block out the noise completely (in fact, none of the above methods guarantee a completely silent home) but it could help lower your blood pressure!
- Consider moving away from the increasingly popular wooden laminate floors and install carpets. Couple with a soundproofing mat and voila, you have helped your neighbours and blotted out their 2am inebriated post-pub routine.
- Or, if you want to go right back to basics, how about just a shift around of your furniture? Consider the rooms in the neighbouring properties and where they are in relation to yours. Is their living room against your bedroom? If their television is keeping you up at night, consider having fitted wardrobes installed to the party wall to help block out the noise. At the very least, don’t have the head of your bed up against that wall. Are their bathroom habits disturbing the peace you seek in your study? If their bathroom is against your study, think about creating bespoke bookshelves against the partition wall and stock full of your favourite tomes. If anything, it’s a good excuse to buy books!
- There are ‘Robust Standards’ to follow in terms of sound proofing. These standards are proven to reduce sound transfer to an acceptable level. Therefore, if you carry out a quick Google search for a specific Robust Standard on floor or wall junctions, you will see the type of construction we should try to achieve as a minimum and then see how different your existing walls or floors are actually constructed.
- Details are important. Don’t just apply dense materials or resilient layers and think that’s it. If you fill a joist void with dense insulation but forget the narrow gap between the last joist and wall structure, air borne sound will just travel through the forgotten areas. If you apply a resilient layer but fix through it then it may as well not be there. So be warned, watch the details if you are improving sound insulation and do it right!
Gary Naftel BSc(Hons) MCIArb MRICS
The information in this Coffee Break article is intended for guidance only. The authors cannot accept any liability for any loss or damage which may result from the use of this article.