Soundproofing walls and ceilings in Sydney

Realistically, by adding mass to it and sealing it, and accepting that it will not match a wall built for the job from scratch. That usually means a second layer of board over the existing one, ideally on a resilient mounting so the new face is not rigidly connected to the old frame, with every edge and penetration sealed. It costs ceiling height on nothing but a few millimetres of wall thickness, and it makes a real difference to voices and television. What it will not do is deal with low frequency noise anything like as well.

They help, and on their own they will disappoint you. Batts absorb sound within the cavity, but the two faces are still screwed to the same studs or the same joists, so a large part of the sound travels through the framing regardless of what is between it. If the wall or ceiling is open anyway, put acoustic batts in, they are cheap at that moment. If somebody is quoting you batts alone as a soundproofing solution, ask what else is in the system.

You work from the room side, because opening the wall is usually the more expensive option. Adding a layer of dense board over the existing lining, mounted so it is not rigidly tied to the old frame, then sealing the perimeter, is the standard approach and it works. Two things to know before you commit: it moves the wall into the room slightly, and skirting, architraves and power points all have to come off and go back.

This is the hardest one on the page and it deserves a straight answer. Footsteps are impact noise, meaning the energy goes directly into the building structure rather than travelling through the air first, and it then radiates out of the ceiling below. A decoupled acoustic ceiling reduces it, sometimes a great deal, but it cannot remove it, because the sound is already in the structure by the time it reaches you. The most effective single fix is carpet or a proper acoustic underlay on the floor above, which is not usually yours to install. In a strata building it is worth raising with the owners corporation before spending on a ceiling, because floor covering rules often already exist.

The existing ceiling lining usually comes down first. In a house built before about 1990 that lining is checked before anything is pulled apart, because material of that age can contain asbestos, and clearing it is a licensed removalist's job rather than ours. Once the cavity is open, acoustic insulation goes in between the joists, then resilient mounts or channels are fixed across them, and the new ceiling hangs off those rather than off the timber, so there is no rigid path between the structure and the sheet you can see. Dense board goes on, often in two layers with the joints offset, and the perimeter is sealed and kept clear of hard contact with the walls. The whole assembly costs you some head height, which is worth knowing before you start.

Yes, and for most people it is the only option, because the floor above belongs to somebody else. Working from below handles airborne noise such as voices and television very well. It handles footsteps less well, for the reason in the question above. If you do have access to both, treating the floor and the ceiling together is far more effective than either alone, and we will tell you if we think the ceiling on its own is going to underdeliver for what you are describing.

First find out whether it is actually coming through the wall. In a duplex or a terrace the sound very often travels over the top of the separating wall through the roof space, or through a shared duct, or up through the floor structure. Where it genuinely is the wall, adding mass and separation on your side works and does not require your neighbour's agreement. In a strata building, the wall may be common property, which makes it a conversation with the owners corporation before it is a conversation with us.

It is the acoustic rating the Code requires between two dwellings, and the plus Ctr part is the important bit. Rw alone is weighted towards the frequencies of human speech. Ctr adds a correction for low frequency sound, which is traffic, bass, machinery and footfall. A higher number is better performance. The reason it matters to you is that a wall quoted only on Rw can look good on paper and still let through exactly the sort of noise people ring up about. Floors between dwellings carry a second rating covering impact, where the convention is reversed and a lower number is the better one.

Improved, yes. Soundproofed in the sense of silence, no, and anybody promising a percentage on an existing room has not seen it. What is achievable depends almost entirely on how the sound is getting in. A room where the only path is through one wall can be improved a great deal. A room where the sound comes through the ceiling, the floor and a shared duct as well needs all of those addressed or the result will disappoint whatever you spend on the wall.

Almost always flanking: the sound is going around the barrier rather than through it. Over the top through the roof space where the wall stops at the ceiling, along a continuous cornice, through a shared duct, through back to back power points, through recessed downlights cut into a ceiling, or up through the floor. It can also be that the work added absorption rather than mass, which changes how the room sounds without changing what gets in. It is worth diagnosing before spending again.

Yes. Acoustic ceilings are part of what we do, and for a lot of the noise people ring about they are the more useful half of the job. A great deal of residential noise arrives through the floor and ceiling structure rather than through the walls, particularly in units and two storey houses, and treating the wall alone will not touch it. Tell us what you are hearing and where you think it is coming from when you call, and we will tell you which surface is worth spending on.