Do bi-folding doors block sound from the outside?

This is a question we get asked a lot, so here’s a quick overview of how sound travels and how your bifold doors will react to any noise issues.

First of all, how does sound actually work?

Here’s the basic physics: when a noise is made, nearby air particles vibrate. This makes further air particles vibrate, and the sound is carried along in a wave pattern. We hear sound because the vibrations are felt inside our ear, detected by the ear drum. A loud noise will cause bigger waves, which will arrive at our ears as a louder sound. A good visual representation is a rock thrown into a pool of water: tiny pebble, tiny ripples; big stone, big waves which travel further. Sound waves can be absorbed by soft surfaces, and they are reflected by hard surfaces. So a thick carpet will absorb, for example, the sound of feet, whereas a bare room will allow sound to echo.

With windows and bifold doors, it’s the glass which helps with noise reduction

Glass, being a solid surface, will reflect outside noise, cutting down how much will reach the inside of your home. Double glazing in itself can reduce sound by around 50%, and this can be increased by the use of thick curtains to further absorb intrusive noise.

Choosing the right glass will have a direct impact on the amount of noise you’ll get inside your home. The best results for noise reduction are gained using laminated glass.

Lamination, and how it works

With lamination, two panes of glass are held together by an invisible plastic interlayer. It’s a process often used for security and safety, as laminated glass is harder to break. In terms of noise, using panes of different thicknesses means the pattern of any soundwaves is disrupted. And this, in turn, means the noise inside is greatly reduced.

Our lamination choice

There’s a balance to be struck here between the level of noise reduction and cost. As a reference point, airport spec glass uses one layer of 8mm and one of 10mm. If a client comes to us specifically looking for noise reduction, we recommend 6.8mm laminated glass for the outer pane and a 4mm toughened pane for the inner. This is a cost-effective solution offering a good level of noise control with no impact on clarity.

Won’t the glass be really heavy?

Aluminium frames – as used in our bifold doors – can support the heavier glass needed for sound control. Our frames are also made to fit and seal perfectly, leaving no gaps for noise to get through.

So bifold doors with laminated glass will solve all of our noise problems?

The right glass in well-made bifold frames will help to significantly cut down on noise from the outside. What bifold doors can’t do, of course, is keep that sound out when they’re open. If you live in an area with high levels of noise, though, you will have control over this, enjoying the light and view bifolds offer from the peace of your home.