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Soundproofing is an important step in building or renovating any home. It helps make our homes more peaceful, comfortable and relaxing. Soundproofing can also boost productivity for those working from home, blocking or reducing noisy distractions.
Here’s our guide to soundproofing different parts of your home effectively and safely.
How soundproofing works
Understanding how soundproofing techniques work can go a long way in implementing them. A sound is a vibration of varying frequencies that travels as an acoustic wave. Soundproofing any space involves adding an intermediate surface that will either deflect, diffuse or absorb these sound waves.
For a surface to deflect sound, it needs to be very dense. If you’ve ever been inside a sandstone building, you’ll notice that loud outdoor noises drop away. Compare that to noise levels in a brick veneer home beside a busy road. A single layer of hollow core bricks simply cannot adequately deflect or absorb sound.
While efficient, sandstone blocks are obviously not cost effective. A simpler and more budget-friendly sound absorption technique is insulation. It slows and spreads undesirable soundwaves, reducing or eliminating the noise.
Sound absorption also involves reducing sound reflection or bounce within a room. Reflection occurs when sound waves bounce off surfaces and you get an echo that makes a room or space sound very hollow. These environments allow sounds to travel further without dispersing or losing their intensity.
Deciding where to soundproof
When soundproofing your home, the first step is to determine where undesirable or excessive sound is coming from. It could be from an external source, like roads and rail lines, or somewhere within your house.
For external sources, locate where the sound is originating from. For example, if the sound is coming from a busy road, you can apply multiple soundproofing methods to the front wall facing the road and lower scale work to other areas. However, keep in mind that sound may still travel through a space like a roof cavity.
For noises originating indoors, a simpler and more budget-friendly option is simply to isolate noisier rooms, like a media room. Rather than soundproofing the entire home, you can create individual quiet spaces, like bedrooms.
How to soundproof walls
Think about soundproofing as adding additional or amended layers to your walls to dampen noise. A regular brick veneer or clad wall is a series of layers – brickwork or cladding on the outside, insulation foil and framing in the middle, and then plasterboard on the inside. These layers do help in reducing noise. However, there are several things you can do to make your walls more soundproof. These include:
- Opting for double brick when constructing a new home or new extension. This means you have an external and internal brick wall. This double brick layer reduces sound because it is more dense. Unfortunately, it is also more expensive to construct.
- Exploring the cladding and weatherboard options available. A regular wall board is around seven to eight millimetres thick. You’ll find options that are as thick as 16mm are better at soundproofing and also contain better thermal insulating properties.
Use thicker weatherboards
How to soundproof a cavity
The empty space between the external and internal walls is called the cavity. Soundproofing this space is the simplest and most cost-effective way to reduce noise. Here are some things to consider when soundproofing a cavity:
- Choosing the right grade. Wall insulation comes in a range of grades. This scale, which is the same as the one used for ceiling insulation, is based on the R-value of the insulating material. The higher the R-value, the better the insulation. The insulating materials become denser with each step up.
- Ensuring the insulating material for your cavity is rated for sound, and not just for its thermal properties. Some products, such as foil covered boards, are excellent at thermal insulation, but may not be dense enough to dampen sound.
How to soundproof internal linings
Plasterboard is the material of choice for internal wall sheeting among most homes today. Typically, these plasterboard sheets are 10mm thick and offer a minimal level of soundproofing. Better options include:
- Acoustic plasterboard. For quality noise reduction, use plasterboard that has been engineered for sound reduction. While still only 10mm thick, these boards are denser. They are heavier to work with and more expensive, but provide quality noise reduction over a wide area.
- Fire-stopping boards. These commercial-grade boards offer dramatic reduction in sound transmission. They are denser and thicker, ranging between 13mm and 16mm, and are ideal for use on walls facing busy roads.
Use acoustic plasterboard
Unfortunately, these materials aren't cheap, so it’s unlikely you will use these acoustic boards to soundproof every wall and ceiling. Instead, focus on noisy areas and on creating specific quiet rooms.
How to soundproof ceilings and roof cavities
Cavity insulation, along with acoustic plasterboard in internal walls, can dramatically reduce sound transmission between rooms. After you’ve dealt with those vertical areas, there are also the horizontal parts of your home to consider, like floors and ceilings. Here are some ways to soundproof those areas:
- Using acoustic-grade plasterboard for your ceiling sheets. This is a great way to reduce external noise and minimise noise transmission between levels in a multi-storey home.
- Adding high R-value insulation to your roof space above the plasterboard or to the cavity between ceiling and floor in multi-story homes. This reduces sound transmission and improves your home’s thermal performance. Ideally, every home should have ceiling insulation with the highest R-value possible.
Insulate walls and ceilings
For elevated homes, consider sub-floor insulation This is designed to friction-fit between the joists beneath your floor. Not only does it effectively reduce noise transmission, it also acts as a thermal insulator.
How to soundproof windows
One of the biggest sources of noise is through windows. Unfortunately, regular window glass is a poor insulator. Here are some ways to make it more soundproof:
- When designing or renovating your home, reduce the number or size of windows that face noisy areas like a main road or a neighbouring home.
- Opt for double-glazed windows in rooms directly facing noisy areas. Double glazing involves two panels of glass with an air gap in between and is very effective at reducing noise.
- Regular window glass is typically between three to five millimetres. Talk to your glazier about increasing this thickness to decrease noise.
- Consider thicker glass that is also laminated. Laminated glass tends to be better at filtering higher pitched sounds, like aircraft noise.
- Retro-fit windows with window film that is designed for noise reduction.
- Add quality window furnishings.
How to soundproof doors
Doors are a fantastic opportunity to block noise. When you are selecting doors, ensure you check their acoustic qualities.
A typical hollow core door, for example, will do very little to reduce noise transmission. Replacing bedroom hollow core doors with solid panel doors can lead to excellent reductions in noise transmission.
The forgotten noise leaks
Noise has an annoying habit of finding its way into different places. An important part of soundproofing your home is to deal with any cracks and gaps in walls, between boards, around windows, door frames, pipes and vents. This can be easily done using gap sealants designed for specific areas.
Remember to also seal gaps underneath doors. You can use a suitable draught or weather exclusion strip for this.
Reducing reflected noise
With more homeowners preferring hardwood floors over carpeted ones, homes have become noisier. We also have a lot more things generating noise inside and around our homes – big TVs, home theatre sound systems, games consoles, dishwashers, washing machines, reverse cycle aircon units and pool pumps. Apart from the steps we’ve outlined above, there are some other ways to reduce reflected noises coming from these sources. These include:
- Decorating your home with soft furnishing. This includes couches, throws and cushions. They all work to dampen sound. Make sure there’s an abundance of them in areas like the TV room.
- Using rugs. They are excellent at dampening sound, especially in areas with hard floors. A hall runner down a hallway can make an enormous difference to how far sound moves.
- Laying a carpet in rooms that are noisy, like the TV room. Go for denser carpets as they help with greater sound absorption. It is also more comfy to sit on.
- Using premium quality underlay beneath carpets. Quality underlay is thicker and denser. Not only is it much nicer to walk on, it is also effective in blocking noise.
- Installing quality curtains. Full light block-out ones are the best, followed by pull-down blinds that have air spaces in them. These are often called honeycomb blinds. Either of these options will be effective at minimising reflected noise and reducing noise coming into your home.
- Hanging artworks on walls, preferably fabric or canvas. They may not do much to reduce noise levels but they can reduce sound bouncing from one surface to the other.
How to soundproof outdoor areas
With busier suburbs and smaller house blocks, many homeowners struggle with noise pollution in their outdoor spaces. Here are some things you can do to make these areas more soundproof:
- Building new fences. Choose your fencing material wisely. Instead of the commonly used Colorbond panel fence, traditional timber fences made out of Pine or hardwood are more effective at reducing sound reflection and transmission. For very noisy areas, there are also acoustic fencing panels that are extremely effective.
Tin fences reflect sound
- Modifying fences. Don't fret if you have a metal panel fence and can’t change it. You can still make it more soundproof. Running wire or attaching panels on stand-offs allows you to grow climbers to cover the fence. These won’t totally stop noise but they will dampen and reduce sound reflection. If you can’t grow plants then consider adding screening panels, preferably made out of timber. These will add a baffle layer that reduces sound transmission and reflected noise.
- Screening. Adding freestanding screening around outdoor entertaining spaces and in front of windows can work wonders to reduce noise. You can then give it a green touch by training climbers over it.
- Selecting surfaces well. Paved and concreted surfaces are sound mirrors. Adding furniture and pots can help reduce this. However, timber decking works better at reducing sound in entertainment and dining spaces. For other outdoor areas, lawn or well-mulched garden beds are excellent at stopping reflected noise.
- Planting. A well-planted garden is any essential part of a noise reduction strategy. The combination of plants and mulch will help to reduce sound movement. Better still, consider adding planting mounds as these will both absorb and deflect noise.
- Securing outdoor equipment. Make sure aircon units and heat pumps are properly secured and not rattling. If they are close to habitable rooms, then consider enclosing them to reduce sound levels. Don’t forget pool and spa pumps too. They are simple to enclose and can dramatically reduce unwanted noise.
Add a water featureAdding white noise. You can make an outdoor space more enjoyable by fighting noise with noise. Adding a water feature with a splashing and gurgling fountain or cascade will provide white noise that can assist in cancelling unwanted sounds.
Need more help?
Check out these tips on soundproofing windows and bedrooms by experienced members of the Bunnings Workshop community.
You can also ask for more help with your soundproofing project by clicking the Start a discussion button. We'd be happy to assist.
