It is fine to use as long as your wall has little to no water infiltration. It tends to completely fill the cavity in your wall, leaving little to no room for air movement and thus drying, so, if your wall tends to be moisture prone (i.e. in a wind-driven rain exposure location, without protective overhangs, poorly detailed, etc.), you can end up with the cellulose harbouring moisture, and thus potentially growing mold.

Sagedaddy is totally correct. There is another consideration as well. Cellulose can be flame retardant or not flame retardant. If not flame retardant, then cellulose can be a fire hazard, as opposed to fiberglass which is not a fire hazard. On the other hand, if the cellulose is flame retardant, then it is important to know how it was made flame retardant. Ask. Also, ask for the MSDS sheet on it and read it.

Now, all that suggests that perhaps fiberglass might be better because fiberglass is not flammable and doesn't pose water/mold issues. However, fiberglass may release fiberglass dust which is a serious concern if inhaled.

So, from a health and environmental perspective, the cellulose is the better choice, but only if water and flame issues are not the priorities. Otherwise, go with fiberglass that is well wrapped.

Barry A. Cik, Board Certified Environmental Engineer

I have been looking into insulation options and my concern with the cellulose is that it can corrode pipes and wiring due to the high amount of boric acid (which makes it flame retardant). I've also read that it offgasses formaldehyde. These are just things I have read and I am curious to hear if they are true? It's so hard to know what is best.

I was also interested in the benefits of cellulose. Is there any insect problems involved with using this material? I read something about termites that eat cellulose? has anyone heard anything about that?

When our home was built 3 years ago, we used cellulose insulation and our utility bills are on the average of 30-50% less than our neighbors whose homes are of comparable or less square footage. I believe strongly that this is due in large part to the insulation. My husband and I were told that the cellulose was made of shredded newspaper and borax to make it flame-retardant. He took a lighter to it and it was virtually impossible to get it to catch on fire. The worst it did was emit a little smoke and smolder momentarily at the contact point of the flame. We have been very pleased...I hope that the ink in the newspaper doesn't pose it's own threat.

We moved into this custom built home nearly two years ago. We used cellulose insulation and while my utility bills are satisfactory, this is the dustiest house I've ever lived in! I wonder if the cellulose sifts through the ceiling and walls. We have radiant heat so I know it is not blown around by a forced air system.

Our house had cellulose insulation -- the variety sold at home improvement stores that you do it yourself by renting the insulation blower. The do it yourself version has ammonium sulfate, zinc sulfate, and boric acid. I can attest to the house always being dusty. It was migrating through the wall cavities via the forced air system, and just by the pressure changes from doors, windy days, etc.

Because of sensitivity issues, we had it professionally extracted, but the residual dust is so spread through the walls and such and such we can't live there. Apparently ammonium sulfate gets into an aerosol/vapor/particulate state where it's so small (possibly down to 6 nanometers) that even HEPA's can't clean it, and since it's still kind of a solid, carbon can't catch it. My 4 year old daughter is so sensitive from living there that she reacts anywhere we go that uses cleaners with ammonia or ammonium.

The variety installed by the pros uses only boric acid, not the sulfates. But obviously if the cellulose gets into the house, the boric acid dust (being smaller) is being breathed also.

The safest insulation I found was Bonded Logic's Ultra Touch denim insulation. It uses boric acid also, but it's a batt product (vs loose) so it's more contained to the attic or walls.

From what we've experienced, insulation contributes to health issues much more than people realize.