Most packing peanuts are made of polystyrene.
Can you use packing peanuts as insulation.
In the course of some framing it seems that there are spaces which get closed off and won t get insulated unless the gc does it on his own nickel during the framing process.
If they get wet they ll dissolve and they re made to be highly biodegradable so they ll break down pretty quickly anyway.
In a wall cavity they would offer little resistance to air movement so they would be of limited r value.
The very reason why plastic peanuts work well as packing makes them a bad choice for wall insulation.
By preventing heat loss packing peanuts make lovely insulators.
As far as being a fire hazard eps from which the peanuts are made can be and has been legally used in sheets for insulation as long as it s covered by a fire rated barrier such as drywall as bsee cm suggests above i would expect that if you were using peanuts in a wallspace that you would want to compress them as much as possible to maximise the extent to which they entrap air.
Osborn a former associate editor replies.
Foam packing peanuts as insulation.
Plastic peanuts hold air that helps cushion whatever is being shipped.
The r value of polystyrene is about 4 0 per inch.
If the packing peanuts are newer they won t work.
I m not sure when they switched to the new kind but it wasn t more than five years ago or so.
Yes packing peanuts are excellent insulators because they are made out of styrofoam.