Impact sound insulation testing
Turnaround and logistics
- Typical turnaround
- About two weeks from receipt of a complete specimen and an agreed scope
- Urgent work
- An urgent route is available — tell us the date you are working to at enquiry, not after booking
- Before you ship
- Confirm specimen size, mounting and packing first — see sample requirements
- Report language
- Reports issued in English; correspondence in Thai or English
Tapping machine testing on the standard floor. The number that matters commercially is usually the improvement your product delivers over the bare slab — ΔLw — because that is what a specifier can add to any floor construction.
Impact sound is not sound insulation
Airborne sound insulation asks how much of a sound in one room arrives in another. Impact sound asks something different: when the floor itself is struck, how much noise appears in the room below. A floor can perform well on one and badly on the other, which is why specifications name both and why substituting one result for the other does not work.
The measurement uses a standardised tapping machine rather than a loudspeaker, because the source has to be repeatable — footsteps are not. What is reported is the level in the receiving room, so unlike sound insulation a lower number is the better one. That inversion catches people out when reading a report quickly: a good impact result and a good airborne result look nothing alike.
What actually decides the result
- The covering, far more than the slab. A resilient underlay or a floating layer changes the result dramatically; the structural slab underneath changes it comparatively little.
- The improvement, not just the absolute. For a floor covering the meaningful quantity is the improvement it delivers over a bare reference floor, because that is what transfers to a different building.
- The bond line. An underlay laid loose and the same underlay fully bonded do not perform the same. State how it will be installed in practice — testing a condition nobody builds produces a number nobody can use.
- The edges. Rigid contact at the perimeter short-circuits a floating floor. This is the single most common reason a laboratory result is not reproduced on site.
Which rating do I need — Ln,w or IIC?
It follows your specification, not your preference. Ln,w comes from the ISO route and IIC from the ASTM route. They are not interchangeable and they do not convert by a fixed offset. If your project is specified to one and your product was tested to the other, you have a problem worth resolving before the submission, not after.
Can you test my covering on the slab we will actually build?
Tell us the construction at enquiry. The reference floor used in the laboratory is defined by the standard, and where your build-up differs materially from it we will tell you what the result will and will not represent before you commit.