A guide to understanding the confusing world of acoustics by Toby Makin MIOA
Replacing a carpet with timber or laminate flooring?
Many people want to replace carpet with a decorative timber or laminate flooring, but there are often concerns from neighbours and landlords relating to the potential noise problems that may result. The solution is to choose an appropriate product to help control the noise, ensuring that the new timber or laminate flooring does not cause disturbance to the neighbours, and this can get confusing with so many different websites and products pushing a range of technical data, but what do these numbers really mean?
The most common number you’ll come across, particularly on underlays for laminate floors sold in DIY shops, is the ‘Delta Lw’. Most ~5mm thick products offer around about 20dB, but does that mean you or your client will get 20dB when it’s fitted under a laminate? In short, not likely. This measurement (made to an industry standard methodology that most of us would never have to read, BS EN ISO 140:8) is frequently stated on packaging, but in practice bears little resemblance to the typical scenario of laminate flooring replacing carpet over a traditional timber floor structure. Actually, it’s a comparison between a bare concrete floor and the concrete floor with the underlay in question laid over the top, but crucially without the final hard, noisy, clip-cloppy laminate flooring. When installed on a typical floor, these products actually act as a very useful levelling layer, ensuring that the laminate flooring is not wobbling over the inevitable undulations of a floor, but is never realistically going to perform anywhere like as well as it says on the packet because you’d never use them in isolation.
So, how do we get something that works? The key is to understand what’s changing when laminate flooring replaces carpet - out goes the soft cushioning layer at the point of impact, and in comes a hard layer. When installed on a typical timber floor structure the ‘thud’ of footfall is accentuated and the new ‘clip clop’ noise of hard shoes hitting the floor is introduced. It’s obvious why this causes so much disruption! In practice we need a resilient layer that is going to create a ‘floating’ floor, not just a levelling layer and for that you need something a bit thicker that will typically have a Delta Lw of at least 35dB, the increased performance is directly linked to it being a bit thicker (~10mm). In addition, to combat the new clip-clop airborne noise, more mass is needed as a barrier layer, typically at least 12Kg per square metre or more, though if the subfloor is concrete and already very heavy, this isn’t required. A good example of two products that meet these criteria, are the two heavier versions of Acoustilay, Acoustilay 8 and Acoustilay 15. These products combine a long lasting resilient core with a mass loaded acoustic barrier to effectively control both the ‘thud’ and the ‘clip-clop’ noises associated with hard floor finishes. You can find the Acoustilay technical data, installation guidance and fitting video’s at www.soundreduction.co.uk or, alternatively, respond to this editorial for your free sample and brochure.
By using a little common sense, and reading past the attractive claims of performance, it’s possible to select a specification that will allow a range of floor finishes to be installed without inadvertently generating a difficult noise problem in the process. As always in acoustics, if it seems too good to be true, it usually is! Cheap, thin underlays will not, in our experience, offer anything like the acoustic performance required when replacing carpet with laminate.
Sound Reductions Systems have a wide range of acoustic flooring products to tackle any acoustic flooring issue, along with the most experienced and qualified technical team in the market, and their advice is always free of charge. To talk over any acoustic issues you may have please call 01204 380074 or email your enquiry to firstname.lastname@example.org