I am not familiar with any wood product that won't burn. I did some research into cork sheet and found the most common binder is polyester. I did find a reference that treated cork might be rated as "fire resistant" which means nothing. I did find a flame test for a 50mm (2") cork board that resisted flame penetration for 4 hours at 1500*f. I doubt 6mm cork bits in a polyester binder would do as well.
6mm cork has an STC (sound transmission class) of 23. 3mm (1/8") of mass loaded vinyl (1lb sq ft) has an STC of 28. 6mm (1/4") of mass loaded vinyl (2lb sq ft) has an STC of 32. That's a pretty big difference.
Cork can be a good thermal insulation and a decent decoupler when used correctly, that's why you find it in flooring, to decouple hard finish floors from the structural sub floor.
The reality is that combustibility just isn't that important in a fiberglass or wood boat. There is already so much fire load in a typical engine space like wood, rubber, lubricants, the fiberglass itself, that it's really not an issue. Vinyl / Foam composite insulation has been used in boats for decades.
For a steel or aluminum boat it should strictly be incombustible insulation, because the structure of the boat is itself incombustible.
I understand that you seem to have religion over cork, but unless the laws of physics are different in Hong Kong, 6mm of cork is not going to perform as well acoustically as 6mm of mass and especially mass in a composite of absorber and decoupler.
Originally Posted by Searios
Your mentioned examples might burn if exposed to an open flame - cork will not...it's cheap, available, fire "safe", noise and thermal insulating..
Is there a another product available out there with these properties?
The density and size of the cork mix is important - so make sure you order the right mix - follow the link that was posted earlier on...
Buy a roll from China, glue it on..