When I had my house built, it got cold and so we called the local power co-op energy savings expert to give us advice. One of the things he said was that we had the wrong kind of insulation in the attic, that it needed to be a higher rating. So, we hired an insulation company and they used something instead of fiberglass called "poly". They vacuumed all the treated, recycled newspaper insulation that was previously used, and brought in the poly, which they blew in. This worked well and among the other changes we did, it warmed the house up.

But then one of the attic fans broke where the fan part spun off the spindle because of a poor weld. This caused sparking as metal scraped metal and I ran into the attic to shut it off in the nick of time. We hired an electrician and he took the fan motor and blade into his shop and re-welded it back on very nicely, as well as added a bolt for extra reinforcement. This lasted us for several years until this year, when the bearing on the motor broke and it made an awful noise. The bearing was such that it would stop and start, but once it got started, it would run fine.

So, my fears are:

  • Is this poly stuff fireproof and the proper stuff to insulate my attic with?
  • What attic fan make/model would you recommend (I have two of them and they seem underpowered for my hot attic) that can withstand the extremes, last long, and reduce my fire risk?
  • What safety measures can I add to my attic to reduce the fire risk?

The other thing I don't understand is -- I've lived in several houses before over several decades, each with attics. I've never had to worry about attic fans at all until this house. Why is my attic an issue?

  • not familiar with the term "poly", could it be cellulose? Apr 13, 2011 at 6:58
  • To answer your question we will either need a picture or the name of the insulation. Was it cellulose, cotton, wool, wood shavings, recycled glass or Spray foam poly urethane insulation. The latter requires that other fire retardants be used in conjunction with this insulation such as sheetrock.
    – allindal
    Apr 13, 2011 at 17:28
  • It was blown poly -- that's all the guy said to me. It's soft to the touch, like cotton, but plastic. Doesn't scratch your fingers like fiberglass. Smells like plastic but only if you hold it up to your nose. I'm thinking of taking some of it out in the backyard and setting it on fire, to see how fast it burns. If it burns super fast, I'm going to have to do something about this.
    – Volomike
    Apr 14, 2011 at 5:59
  • Can you cut a small slice from "poly" and try to set it on fire in a controlled safe manner?
    – sharptooth
    Apr 14, 2011 at 13:47
  • 1
    @sharptooth. It's the strangest stuff. I tried to ignite it in a container in my garage. It was resistant to melting at first, but then melted rapidly after the flame got hot enough. It had only weak fumes, no smoke, and never caught fire. It was like it absorbed the fire and put it out.
    – Volomike
    Apr 15, 2011 at 17:56

1 Answer 1


So I've learned that the poly is fire retardant, but it would be better not to expose it at all and use fireproof boards over all of it, instead.

For the fans, I found a slight water leak on one, and now see that solar attic fans are probably the better route. I will consult an electrician to install some from Lowe's.

  • 1
    Anytime you can avoid having line powered devices with motors from non-occupied areas, it's a good thing. They can occasionally fail in fire-producing ways! Passive is best, but if you must absolutely have the motors, low-voltage is better than line voltage. Apr 20, 2011 at 19:20

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