All our Floor solutions:    |   SBX Floor   |   Absorbalay High Impact   |   Acoustic Underlay   |   Floating Floor   |   Below Floor Soundproofing   |   Replacement Soundproof Chipboard Floor   |   SIF Under Floor Hangers

Soundproofing Below Floor Boards

Under floor sound proofing with an optional layer of acoustic plasterboard

For a highly effective method of floor soundproofing against airborne sound we would recommend the following system. It incorporates acoustic mineral wool, and a layer of high performance acoustic membrane "Tecsound 50". The images above show a cross sectional diagram of a typical floor post the application of soundproofing materials.

In a situation where you want a good result with less effort and you can only work beneath the floor boards we highly recommend this solution. The Tecsound membrane can be applied either above or below the floor boards ( or for even better results in both places!). We can now offer Tecsound 70 which is a slightly thicker and heavier membrane for those who want to maximise performance.

We also outline an alternative solution which incorporates further protection in the form of a further layer of plasterboard planc. The addition of the 19mm plasterboard acts like an additional ceiling below your floor. Where possible gaps should ideally be sealed between the floor boards using acoustic mastic. The effect of this shouldn't be underestimated and can often be like closing a door that has been left ajar.

The floor will now have several layers of protection. Acoustic mineral wool, Tecsound membrane and 19mm plasterboard planc, and sealed floor boards. 

For customers looking to insulate noisy pipes please see our acoustic pipe wrap

NOTE: where noise from below is your problem you should be concentrating on getting the maximum airborne uplift you can. Rubber mats vastly improve impact sound reduction (benefitting downstairs neighbours), they are not as good at reducing the sound coming up.

Comparing our products with others:

Please note that the figures that we provide refer to improvement over the average floor as opposed to the performance data of the product in isolation. By this we refer to products that can be lab tested in a way that the product is tested on its own, which can give little indication how it performs in situ (i.e. on your floor)

This is a very important distinction to understand and is confusing to a lot of people. Almost all our competitors will state the performance of the product either in isolation or include the existing floor construction within their numbers. This will exaggerate the true benefit of their products. For more information click here. This is particularly the case with laminate underlays.

Sound proofing basics

When it comes to soundproofing your floor , it is important to establish what you are trying to achieve. Are you trying to stop noise from below reaching you, or are you trying to eradicate your impact noise passing down to your neighbours?

In practice, most people are aiming at stopping the sounds from below traveling upwards. Many products on the market boast great soundproofing credentials (particularly rubber mat or underlay solutions) but the figures quoted are almost always referring to a reduction in impact sound and are of very little use in identifying how much airborne sound is being reduced.

Understanding Performance
At the foot of the page you will see a performance table.

The total performance which is normally quoted on most sites refers impact sound only. However if you are worried about sound rising from below, you should only consider the airborne sound number (which is rarely quoted).

We also give an indication of acoustic performance uplift. Remember that every 10dB of performance uplift corresponds to roughly a 50% improvement in the performance of the floor. So 20dB would indicate a 75% Improvement over and above the original floor.

Important Note*

As a consumer comparing different products from different companies is very hard. While we talk about improvement in decibels in all our tables many other companies will state a single figure for their products which is often in excess of 40 or even 50dB. It is really important to understand that these figures invariably refer to the performance of a whole floor ceiling structure, and this will include a standardised floor and ceiling that will already offer some soundproofing. There is no single product in existence, to our knowledge that will provide in excess of 40 dB when added to a standard floor ceiling divide (plasterboard ceiling and wooden floor).

In an attempt to level the playing field, we are taking a standard ceiling; 12mm plasterboard, a void and 18 mm floor boards as our case study. We believe that this has an acoustic performance of about 34 dB rw (airborne). The final column of our table gives an indication of we believe our system might achieve in Rw( simple airborne performance) terms.

An important word about regulation E (the sound test required for conversions). We have a dedicated regulation E web site The figures in the above tables do not take into account Ctr corrections so do not attempt to create an off the shelf solution for regulation E.


Key Points:

  • Soundproofing for under your floor
  • Economic and effective underfloor soundproofing
  • Triple protection against sound rising from below.
  • Online calculator will work out your exact requirements
  • Soundproofing kit delivered to your door in 48 hours


Solution Calculator

Loading Calculator... [reload]

Download Fitting Instructions Fitting Instructions

Below Floor Soundproofing Sound Insulation performance table

Floor Depth Gain Total system Performance airborne Typical Airborne Improvement Typical Impact Improvement
Acoustic Mineral Wool and Tecsound 50 2mm if Tecsound above floor 50 dB 13 dB 3 dB
Acoustic Mineral Wool and Tecsound 70 3mm if Tecsound above floor 52 dB 15 dB 3 dB
Acoustic Mineral Wool, Tecsound 50 Plasterboard Upgrade 2mm if Tecsound above floor 56 dB 18 dB 3 dB
Acoustic Mineral Wool, Tecsound 70 Plasterboard Upgrade 3mm if Tecsound above floor 57 dB 19 dB 3 dB
As with all our performance tables we give a total performance figure which is the performance of the whole ceiling/floor when insulation materials are installed. The typical improvement is an indication of the uplift in performance over a basic floor/ceiling structure.
Compare all our floor solutions here.

*Please note figures stated for total system are based on a a timber joist ceiling floor construction with 200mm joist. The figures are Lab figures and are Ctr corrected. So are not comparable to regulation E Systems. The improvement figures state improvement over a regular timber floor and plasterboard ceiling.