Can You Use Packing Peanuts As Insulation

The r value of polystyrene is about 4 0 per inch.

Can you use packing peanuts as insulation.

Styrofoam is designed from air bubbles that are trapped to prevent heat energy from escaping. By preventing heat loss packing peanuts make lovely insulators. If they get wet they ll dissolve and they re made to be highly biodegradable so they ll break down pretty quickly anyway. 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.

Most packing peanuts are made of polystyrene. 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 very reason why plastic peanuts work well as packing makes them a bad choice for wall insulation. Yes packing peanuts are excellent insulators because they are made out of styrofoam.

Osborn a former associate editor replies. In a wall cavity they would offer little resistance to air movement so they would be of limited r value. Plastic peanuts hold air that helps cushion whatever is being shipped. 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.

I m not sure when they switched to the new kind but it wasn t more than five years ago or so.