Sound Proofing Floors – 1. Adding Mass

Sound Proofing Floors – 1. Adding Mass

How do I soundproof my party floor? Well, that’s a very common question, so let’s start with a quick explanation of the main 4 elements of soundproofing construction for floors. They are:

                        1. Adding mass
                        2. Decoupling of materials
                        3. Noise absorption
                        4. Noise damping

Once you have understood how the above elements make up party floor construction, you’ll have a more educated eye the acoustic design on your project. In a nutshell we are trying to prevent vibrations from crossing the floor partition into adjacent dwellings.


When it comes to soundproofing floors, we cannot underestimate the importance of adding mass to the floor construction. However, simply adding mass is not often enough, you also need to consider two important factors:

                        1. The type of material to use.
                        2. The positioning of the material within the wall construction

One most common way to add mass to a floor, is to use soundboard or cement board. Although this will indeed add mass to the floor and decrease sound vibration it will not reduce deep bass sounds from being heard. Another good reason for adding mass is it provides extra insulation, which in turn makes the room more energy efficient and environmentally friendly, something we are all aiming for in new build or refurbishment  developments.


How do I work out the required mass a party floor?

Working out required mass required for party floors to pass the sound insulation test (or simply reduce noise) can be quite difficult. For instance, the acoustic rating of a typical existing joist floor will be approx. 32-35dB. This is because the construction is often made up of 190mm timber joists with no acoustic wool installed to the joist void, then a single layer of 12.5mm plasterboard fixed directly to the underside of the joists, and above the joists one layer of 20mm existing floorboard – which are often badly warped with large gaps between the boards. This type of construction needs to improve by approx.10dB; or, by 100% to pass the precompletion sound testing.

How to improve the mass in your Party floor

To improve the mass, it is usually best to add two layers of 15mm soundboard to the floor construction, you can also add a layer of 19mm Sound Plank and acoustic insulation with a minimum mass of 60kg/m2.  It’s worth remembering for sound to conduct through a party floor, it has to actually move or vibrate the floor construction ever so slightly. A heavier mass floor is always much harder to move than a lighter floor construction. It is especially important to note that a heavy floor will still vibrate, just not as easily as the lighter type, with this in mind we then need to use the 2nd element of soundproofing floor design, which is the Decoupling of materials – this is covered in our next article here.


Getting the acoustic design for right from the word go, is key, and APT Sound Testing can help in all areas of sound insulation design and testing for party floors. Get in touch on  to request a quote or call us on 01525 303905 to discuss your development.

Please Note: although we take every care to ensure the information was correct at the time of publication. Any written guidance provided does not replace the user’s professional judgement. It is the responsibility of the duty-holder or person carrying out the work to ensure compliance with relevant building regulations or applicable technical standards.