Perlite in wall cavity recommendations.
I have a 2×4 wall cavity that is only about 5″ wide. The cavity contains a steam pipe which is uninsulated. The cavity is obscured by another wall that makes access to it very difficult.
I would like to fill the cavity with perlite to insulate the steam pipe. I can close up the wall to prevent the perlite from leaking out, and have access to the top.
The house was built in 1928. From the outside: brick, air gap, roofing felt, 3/4″ tongue and groove.
Are the any drawbacks to loose file perlite in this configuration? Is perlite for insulation treated differently than perlite for gardens which is readily available at the HD?
Thanks in advance for your assistance.
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