A Guide to Sound Insulating Your Windows

You might be surprised to learn that traffic noise is the single largest environmental problem that Europe faces after air pollution; it causes over 60,000 premature deaths annually, leading to heart disease, high blood pressure, and a greater risk of diabetes or even stroke.

The question is, how should you soundproof your home?

The first and most important point that you should note is that sound proof glazing is only and can only ever be good as its weakest point. You might build thicker walls, or stuff them with as much insulation as you wish, or even invest in the latest sound insulating windows, but they can never deliver the results that you seek in isolation. It is important to realise that they have to work together for the best results.

How Does Sound Insulation Work?

Sound insulation works in three ways or a combination of them. The first is stopping the noise through the addition of mass to the structure for reflecting the sound. You are essentially creating an incredibly dense acoustically ‘dead’ surface that does not vibrate or vibrates less than other materials. It is referred to as dampening.

Absorption is the second option where sound is absorbed by a material that prevents it from passing through to the other side, such as wall insulation, for instance.

Creating a barrier between one structure and the other is the third option. It prevents the sound from passing between the structures in the form of vibration thus effectively creating a gap that the vibrations are unable to ‘jump’. It is referred to as decoupling.

How Do Acoustic Glass and Soundproof Windows Work?

Acoustic glass helps reduce noise pollution through the dissipation and deflection of sound waves. It achieves this through a combination of the use of acoustic interlayers, glass thickness, and the space between the glass. The sound waves are disrupted by a variation in these.

The general rule is that denser materials tend to be better at doing this, which means that the thicker the glass the better. However, this should also be set at different thicknesses.

It is the reason why just adding a third pane to a unit in a triple-glazed window has just a limited impact in noise reduction. Unfortunately, it is not something that salespersons either understand or communicate effectively to homeowners.

Sound passes through objects in a linear direction. Using glass of varying thickness in combination means that units tend to be more effective when it comes to dissipating and disrupting sound.

Acoustic glazing maximises the effectiveness of this by combining varying glass thickness and specially developed PVB layers applied to the glass in the manufacturing process. They provide yet another layer at another thickness, absorbing and dampening sound and ensuring that it does not pass from one side of the glass to the other.

If thicker and more layers for disrupting sound waves form the basic principle of sound proof glass window design, it means that there are numerous different variables within it for addressing noise of different types.

Soundproofing Secondary Glazing

If you are unable to replace your existing windows with soundproof windows since you live in a conservation area or are the owner of a period property, it is still possible to improve the energy efficiency of your home and sound insulation significantly by installing secondary glazing.

The same principles apply here. Installing energy efficient secondary glazing won’t automatically improve your property’s soundproofing, although, in common with the new energy efficient replacement triple- and double-glazed windows, better sealing is likely to lead to a small reduction in the noise.

As previously seen, that requires specialist acoustic triple- and double-glazing that goes a long way towards reducing nuisance noise and providing a high level of sound insulation. However, secondary glazing can reduce the noise by up to 70 percent.

It achieves this by dampening and absorption just as acoustic double-or triple-glazed windows do but also by decoupling. This is because secondary glazing, by definition, is separate to the external facing window.

Establishing the right gap between your primary and secondary glazing is of great importance if you wish to achieve optimum performance.