My experience with foams says no. We used the fire rated Sonex in some industrial work and I was unhappy with the results in the low frequency, but at the time I was unaware of a better material that would meet the fire code. It is certainly possible that there is a newer formulation that performs better, but I am unaware of anything that performs better than 703/705 type materials, in an insulation or exterior covering.
Bill
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"...it's easier than hitting the kids, and almost as much fun..."
