Does laminated glass reduce noise?
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Can you use laminated glass for noise reduction? And just how effective is it? Join us as we weigh up the noise-reducing potential of laminate glass.
In architecture, context is key.
You can't divorce a building from its environment any more than you can chip a brick from your neighbour's porch and call it a house. Whether they're designing with it or against it, architects are always considering, questioning and responding to the environment around them.
In urban settings, this often means mitigating the thrum and bustle of the city. Using space-efficient design to make the most of limited footprints. Incorporating green infrastructure to enhance occupant well-being. And, yes, choosing materials carefully to limit noise pollution.
Laminated glass can be a key rider in this noise-abating rodeo. It allows architects to harness abundant natural light and the sleek, modern appeal of glass while shielding occupants from the hubbub of the outside world.
But just how effective is it? Let's find out.
The short version: can you use laminated glass for noise reduction?
Yes. Thanks to its thickness and multi-layered construction, laminated glass can act as an effective barrier against noise.
However, its effectiveness depends on several factors. That includes the thickness and weight of the glass, the thickness of its interlayer and the framing system used.
It's also important to consider your use case and adjust your expectations accordingly.
If you want to dull the sound of a busy street, standard laminated glass will do the job and do it well. However, if you need effective soundproofing – in a recording studio, for instance, or an office boardroom – you should opt for specialised acoustic glass. More on that later.
How does laminated glass reduce noise?
Sound, as you'll remember from science lessons, travels through the air as vibrations.
If you want to stop sound from entering a building, you need materials that can either block or absorb these vibrations.
Brick walls are very good at blocking sonic vibrations. So is dense drywall and concrete. Laminated glass, meanwhile, excels at absorbing and dampening vibrations.
That's all down to its unique multi-layer construction. Laminated glass is made from two (or more) glass sheets sandwiched together with a polymer interlayer – usually PVB.
This helps dampen sound in several ways:
- The flexible polymer interlayer acts as a shock absorber, soaking up sound waves rather than transmitting them.
- The two layers of glass vibrate separately, rather than as one monolithic unit. This further disrupts and dampens the sound.
- The sheer thickness of the laminate also contributes to noise reduction.
How much does laminated glass reduce noise?
The answer isn't quite, "How long is a piece of string?" But there are several factors to consider, all of which can affect the noise-reducing potential of laminated glass. These include:
- The thickness of the glass: generally speaking, the thicker and heavier the glass, the more effective it is at blocking noise.
- The type of interlayer used: thicker interlayers absorb more acoustic vibrations and dampen sound more effectively.
- The framing system: when it comes to noise reduction, a piece of glass is only as effective as its frame. That's why it's crucial to choose a suitable framing system. An inadequate or improperly installed frame could drastically reduce acoustic performance.
- The presence of an air gap:
an insulated glass unit (IGU) fitted with laminated glass will generally perform better than a single pane of laminated glass. That's because the air gap between panes also helps deaden sonic vibrations.
That's a lot of factors to think about – but this isn't unique to laminated glass. Noise reduction is a complicated science that requires careful consideration of material properties, location and installation. That goes for
any
material – glass or otherwise.
With all that said, let's look at different types of glass and their typical noise reduction levels – keeping in mind that real-world performance can vary.
| Configuration | Thickness | Approximate noise reduction | Notes |
|---|---|---|---|
| Monolithic (non-laminated) glass | 3mm | 30 Rw | Rw is the weighted sound reduction index in decibels. An Rw rating of 30 is enough to muffle speech at a normal volume. Loud speech, however, can still be understood. |
| Laminated glass (single sheet) | 6mm (3mm+3mm) | 33–34 Rw | Loud speech can be heard but not understood. |
| Laminated glass in an IGU (double-glazed) | 24mm | 38–39 Rw | Loud speech is reduced to a murmur. |
It's worth noting, too, that laminated glass is particularly good at blocking mid- and high-frequency sounds. Speech and traffic noise largely fall into this category, so that's good news if you're trying to block out urban noise pollution.
However, standard laminated glass isn't optimised for blocking low-frequency (bassy) sounds, such as heavy machinery. If these sounds are in the sonic picture, you'll need to use a specialised acoustic laminate instead.
Can laminated glass increase noise?
Under very specific circumstances, yes.
If laminated glass is installed in an IGU with another pane of glass of the same thickness, these panes will resonate at the same frequency. That's bad news because it means certain sounds will be amplified, not dampened. This is known as the "coincidence effect".
In practice, this is rarely an issue. Any good IGU supplier knows how to mitigate the coincidence effect – chiefly by using panes of different thicknesses – and can advise on strategies to reduce its impact.
Soundproofing glass: specialised laminated glass for noise reduction
Laminated glass is effective at reducing noise – especially mid- or high-frequency noise. However, it was never designed for this purpose. It's more of a happy accident than a headline feature.
If you need serious
soundproofing, rather than simply dulling background noise, you'll need a product designed from the ground up for noise reduction.
That's where specialised
soundproofing glasscan help.
Soundproofing glass (or "acoustic glass") is a type of laminated glass incorporating an extra-thick polymer interlayer – often with a soft core. This special interlayer is much more effective at absorbing and dampening sound.
While standard laminated glass typically achieves 33 to 34 Rw, acoustic glass installed in a suitable IGU can yield 48 Rw or more. Specialised acoustic partitions can take things even further, achieving up to and beyond 55 Rw. At that level, loud speech is reduced to a faint muffle or rendered completely inaudible.
Acoustic glass can also be optimised to absorb bassy frequencies – something that standard laminated glass struggles with.
However, it's important to remember that glass is only as good as its frame. To make the most of acoustic glass, it's vital to choose an equally specialised framing system – whether that's an acoustic IGU or a soundproofing partition system.
At ToughGlaze, we've developed TG AG – a highly capable acoustic glass product that's custom-made and cut to size based on your specification. Get in touch with our UK experts today for a quick, competitive quote.
