Thread: Peanut Insulation

I inspected a house today that had Styrofoam peanut type packaging material for attic insulation.

I believe and have heard that this stuff can be highly flammable and when burned emits black smoke that is probably toxic. I will write it up as such.

But, Does anyone know where the codes references that this stuff shouldn't be used or if there are any industry safety warnings about it. I would like to include this in my report to my client for their reference?

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some will biodegrade when wet or moist, i wouldnt worry so much about fire look at all the wood that will burn

Ken,

You are right to think FIRE and TOXIC FUMES ("I believe and have heard that this stuff can be highly flammable and when burned emits black smoke that is probably toxic. I will write it up as such.") ... that is why the code requires ALL plastic insulation to be covered and protected, and ALL plastic insulation to be fire tested.

From the IRC:
- R314.3 Surface burning characteristics. Unless otherwise allowed in Section R314.5 or R314.6, all foam plastic or foam plastic cores used as a component in manufactured assemblies used in building construction shall have a flame spread index of not more than 75 and shall have a smoke-developed index of not more than 450 when tested in the maximum thickness of 4 inches (102 mm), provided the end use is approved in accordance with Section R314.6 using the thickness and density intended for use.
- - Exception: Foam plastic insulation more than 4 inches thick shall have a maximum flame spread index of 75 and a smoke-developed index of 450 where tested at a minimum thickness of 4 inches, provided the end use is approved in accordance with Section R314.6 using the thickness and density intended for use.

- R314.5.3 Attics. The thermal barrier specified in Section 314.4 is not required where attic access is required by Section R807.1 and where the space is entered only for service of utilities and when the foam plastic insulation is protected against ignition using one of the following ignition barrier materials:

- - 1. 1.5-inch-thick (38 mm) mineral fiber insulation;
- - 2. 0.25-inch-thick (6.4 mm) wood structural panels;
- - 3. 0.375-inch (9.5 mm) particleboard;
- - 4. 0.25-inch (6.4 mm) hardboard;
- - 5. 0.375-inch (9.5 mm) gypsum board; or
- - 6. Corrosion-resistant steel having a base metal thickness of 0.016 inch (0.406 mm).
The above ignition barrier is not required where the foam
plastic insulation has been tested in accordance with Section

R314.6.

That means it is required to be tested, and rated, which means listed, and those foam peanuts are not. PLUS it needs to be protected against ignition as stated above.

They NEED to REMOVE all of that stuff.

The homeowner has heard so much about how the foam insulation is better than fiberglass they decided to upgrade.

Seriously, another point (not that you need one) is there is no way to determine the R-value of the "insulation" if this was the only material used and not in addition too what was already there.

Most packing peanuts are made of polystyrene. The R-value of polystyrene is about 4.0 per inch. 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. This air movement will render the packing peanuts completely ineffective as an insulation material. Plus, as stated above, the packing peanuts pose a high fire hazard.

Thanks everyone.
You've been very helpful.

Bruce made a good point about the air spaces between the peanuts.

I always right up exposed foam insulation like the rigid pink and blue stuff as being a possible hazard and emitting harmful fumes in the event of a fire.