Recent changes to the New Zealand building code mean that certain foam products can no longer be used as interior acoustic absorbers if their surface area exceeds 5m². In harsh or damp internal and external environments the options become even more limited as many foamed plastics absorb water, affecting their mass and acoustic performance.

The recently released Stratocell Whisper FR by Forman Building Systems is a suitable alternative. A foam-based material for interior applications, it has been tested to comply with the most stringent requirements of the NZBC, achieving a Group 1-S rating, meaning it can be specified uncovered for internal acoustic applications such as soffits and wall linings.

The acoustic requirements of a space depend greatly on its construction and use patterns; absorbers are therefore ideally selected on the basis of their ability to be 'tuned' to the absorption requirements. It is here that Stratocell Whisper FR differs also from glass and polyester in its sound absorption profile. Where heavier glass wool peaks in absorption at low frequency noise (at around 500 to 1000Hz) and polyester performs most efficiently above 1000 Hz, Stratocell Whisper by comparison shows optimal absorption from as low as 400Hz and right through to 5000Hz. This offers a very lightweight yet rigid, durable and moisture-resistant alternative to existing options.

Problem applications like indoor swimming pools, gymnasiums, shooting ranges and heat pumps now have a tough foam acoustic absorber that can function even when exposed to rain, spray, certain chemicals, ball impact and moisture.

Where it's difficult to imagine turning on the garden hose to wash glass wool or polyester, Whisper is suitable with proven on-going acoustic absorption even after being exposed to diffuse spray contact such as rain or sprinklers. It will also not slump or stain if saturated.