We found millions of packing peanuts loose in the attic presumably intended to function as insulation.
Packing peanuts attic insulation.
The problem comes from the large interstitual spaces between the pieces.
The very reason why plastic peanuts work well as packing makes them a bad choice for wall insulation.
New packing peanuts are made from a type of corn starch.
Plastic peanuts hold air that helps cushion whatever is being shipped.
Osborn a former associate editor replies.
I m not sure when they switched to the new kind but it wasn t more than five years ago or so.
But the problem with using packing peanuts for attic insulation is that while the individual peanuts may have an r value of about 4 0 per inch the peanuts have large air spaces between them which allows air currents to easily flow through a layer of packing peanuts.
The r value of polystyrene is about 4 0 per inch.
Another problem is that newer environmentally friendly cornstarch peanuts dissolve when wet.
The older kind might work okay.
In a wall cavity they would offer little resistance to air movement so they would be of limited r value.
If they get wet they ll dissolve and they re made to be highly biodegradable so they ll break down pretty quickly anyway.
Most packing peanuts are made of polystyrene.
Good insulation works by trapping air.