What is an acoustic floating floor?
If you have ever bought or fitted laminate flooring, rigid click LVT (luxury vinyl tiles) or engineered wood planks, you will have created a floating floor. In short, the term ‘floating floor’ is used to describe a type of floor that is designed to be installed simply by laying it on top of the underlay, rather than nailing, screwing or glueing it to the subfloor.
As a result, the floor you are installing floats above the floorboards, concrete slab or tiles – what is known as the subfloor. Whilst it might seem counterintuitive to have any element of our homes or buildings installed in a way that means it is not securely fixed to the structure, floating floors offer some important benefits – particularly in respect of sound transmission and making rooms less noisy.
Common noise problems with floors
Many of the UK’s homes are built using timber joisted floors. The joists provide the structure to which floorboards are usually mechanically fixed using screws or nails and plasterboards are screwed to the underside to create the ceiling in upper separating floors. The voids created between the joists allow for the property’s services to run, such as water pipes, gas pipes, ducting and electrical cables.
Developers and builders favour this design because it is relatively straightforward, lightweight, and cost-effective and provides the flexibility required for the various trades to work productively on-site. However, this type of floor construction is not particularly good from an acoustic perspective unless acoustically insulating materials are added.
The first acoustic issue is impact noise. If you walk on a bare floorboard, the impact of your shoes creates a vibration noise that transmits through the joist and plasterboard below so that the sound can be heard in the room beneath. This is because the mechanical fixings help to create effective sound paths – i.e. the floorboard is in contact with the joist, as is the plasterboard, with little or no separation.
The same issue arises with concrete floors as the impact sound is directly transferred into the room below through the slab or masonry.
The second acoustic issue is airborne noise, such as the sound of people talking, a television or music playing. The wood used in standard floorboards is not particularly dense and that means sound can pass through with relative ease. Once the sound has transferred through the floorboard, it passes through the air in the voids and through the plasterboard below.
Concrete and masonry floors are much denser materials so they are much better at minimising the amount of airborne sound transmitted through them, but there is always scope for improving sound insulation.
Reducing noise in a floating floor
When you add a floating floor, a layer of underlay is first laid over the existing timber or masonry floor. This provides thermal and acoustic insulation, as well as helping to level some of the subfloor’s unevenness. If you are installing a laminate floor, for example, you can choose from a range of underlay types to provide the level of thermal and sound insulation within your budget.
However, the potential for improving the floating floor’s soundproofing is significant if you know which products to choose. One type of acoustically superior underlay you could opt for is Hush FFR Resilient Underlay, which is suitable for laminate or engineered wood planks. In addition, Hush Acoustics offers highly effective underlay options specifically designed for LVT and vinyl flooring.
The composition of these types of underlay means that they are much more effective than standard underlay at reducing impact sound transmission – and they also provide thermal insulation. They are also thin, with the Hush Underlay for LVT being just 1.6mm thick, for example, which means the floor build-up height is not excessive.
Go further by choosing acoustic floor panels
If your building project allows you to replace the subfloor or create one, significant acoustic improvements can be made by installing acoustic floor panels. These are still floating floors but they can be used in place of floorboards in timber joisted floors and can be laid over concrete and masonry floors.
Acoustic floating floor panels consist of a high-quality chipboard with a resilient layer glued to one side. The chipboard’s added density blocks more sound than standard floorboards, and the resilient layer decouples the board from the timber joint structure to prevent direct sound transmission from impacts.
A wide variety of acoustic floating floor panels are available to achieve the desired level of sound reduction and floor height build-up. The most popular product in the Hush Acoustics range is Hush Panel 28 which meets most needs, but there are many other types which can add more mass or density and thinner panels where minimising the floor height is a priority.
These acoustic floating floor panels can be laid easily thanks to their tongue and groove design. Depending on the target level of sound reduction, it could be that the floating floor panel is laid over a 19mm plasterboard as with the Hush HD1030 acoustic floor system. There is no need to screw, nail or glue the panels – in fact, this should be avoided because it would be detrimental to the floating floor’s acoustic performance!
And, once installed, all that is required is to ensure the perimeter is sealed using a special acoustic strip, such as Hush Seal 20, or a sealant to prevent flanking – noise leaking through the gaps. The newly created subfloor can then accommodate any type of floor covering including carpets.
Don’t forget to fill the voids
One other important consideration before laying the acoustic floating floor panels is to treat the voids between the timber joists. Here, acoustic mineral wool such as Hush Slab should be cut to size to fit between the joists snugly. The reason for doing this is that this mineral wool formulation is far more effective at preventing the transmission of airborne soundwaves compared to air alone.
