While no material is truly 100 reflective the marble floor above is 01 absorptive which is rounded to zero for nrc some materials can have an nrc rating.
Floor material nrc.
The table below gives some nrc ratings for common building materials.
Simply put the sound is not reflected back into the room to create noise.
And that the flooring material itself does not have any soundproofing.
Theaters for example are constructed with a high nrc rating in mind.
Carpet having an nrc rating of 40 50 has the highest nrc rating of any type of commonly used flooring.
Noise reduction coefficient nrc while stc and src indicate how well noise passes through different materials nrc noise reduction coefficient measures how well materials stop sound from reflecting how much sound they can absorb.
The nrc is the percentage of sound that a surface absorbs in other words hits a surface and doesn t reflect.
For example an nrc rating of 75 means 75 of the sound energy coming in contact with that specific material is absorbed.
A quick look at the pros and cons of flooring on the market today.
It has an stc rating of 44 and an nrc of 0 80 and can be added to walls floors and ceilings during or after construction.
Nrc noise reduction coefficient measures the amount of noise absorbed by the material and not reflected.
Because of these ranges and the limitations of the nrc rating system it is highly recommended to have an acoustical professional analyze your particular space materials and installation methods.
Acoustical ceiling tiles are often tested in type e400 mounting which simulates a 16 inch deep plenum.
Vinyl cork and rubber have a fairly high nrc rating.
For example a thick polished marble floor may have an nrc of.
A room with a high nrc rating eliminates background noise and echoes to help clarify speech.
If available it is always best to get the tested nrc rating from the manufacturer.
A material with an nrc of 0 75 would also be considered 25 reflective.
Cellulose insulation is composed of 75 85 recycled paper fiber with the remainder being made up of fire retardant mater.
For example a concrete wall could be 0 to 35 absorptive.
Carpet has an nrc rating of 40 50 and is the most efficient absorptive flooring material.
For instance a carpet manufacturer may indicate an nrc rating of 50 but this rating may be for the carpet pad and sub floor it is not necessarily just for the carpet.
In addition nrc ratings are often provided based on a given assembly.
The nrc is highly dependent on the type of mounting which if not specified is usually a type a mounting abpma mounting 4 where the material is placed directly on the floor wall or ceiling.
Carpet vinyl cork rubber and other types of resilient flooring have higher nrc ratings than hard unforgiving surfaces such as tile stone hardwood and bamboo flooring.
It reduces the vibration resonance within a wall or ceiling absorbing damping and deadening sound.
