Does Cellulose Attic Insulation have an Odor?

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Bob Bird, Bird Family Insulation


If there is anything I’ve observed in these many years of serving Atlanta’s homeowners, it’s this one thing: They each have a nose.

One thing about a nose: they rarely let us down! 

Do we get calls from our Atlanta clients telling us that they smell the fresh new attic insulation we installed in their home? YES!

In certain circumstances, and during certain times of the year, we may get a call from our “Attic Makeover” clients informing us that they can smell their fresh new attic insulation.

 “Bob, it smells like wet paper…

We finished the two-day Makeover on Saturday at 12:30pm. It was already 89 degrees, and the predicted high was 96 for the day. Hillary’s house is a two story, 1800’s southern home with huge wraparound, covered porches.  Her home was located in Monroe, GA.

The day after, Sunday – my son Chris received this text, “We never could get the upstairs below 86 degrees, and today we’ve already got it to 76 degrees! But when will the ‘wet paper’ smell go away?”

Why do some homeowners smell their cellulose attic insulation when most of our clients never smell anything?

4 Truths About Stabilized Cellulose Attic Insulation in Atlanta Homes

1. Any odor from cellulose attic insulation is very short-lived, and only occurs immediately following installation.

    • Only stabilized cellulose insulation has been known to create the temporary odor. When cellulose is installed with no moisture, there is no odor.
    • Aged cellulose insulation has no odor. 
    • Once the odor is gone, it does not return.

2. We install our cellulose insulation using a water sleeve, so that it is stabilized. Stabilized = moisture added. This means that our installer has added a very small amount of moisture that is injected into the paper fibers as it is installed in your attic. A water sleeve is a section of hose that has valves and tubes that connect to a control valve, that is connected by hose to your water faucet. 

You won’t believe this side note about our Atlanta competition. But I say it anyway…

  • Here’s a small side-note for you: I do not know ANY CELLULOSE INSTALLERS in our Atlanta market who install cellulose using a water sleeve. They ALL prefer to install it DRY and extremely DUSTY. This goes for the exterminator companies too. Sadly, this is, in my humble opinion – a terrible disservice to cellulose insulation and to you as a homeowner. You deserve better. You deserve to have it installed correctly. Correctly installed cellulose insulation should be practically DUST FREE in your attic while being installed.
  • Perhaps they refuse to install stabilized cellulose insulation because it’s difficult to do. And it takes longer to install. They install it dry, and try to cope with all that dust. Treating attic crews like this is wrong. Can you imagine fighting to see through all that dust, in an already dark and dangerous attic space?
  • We’ve done this for so long that it’s not hard work for our crews. Beau’s men have this down to an art form!  But isn’t that the sign of a professional: they make the hard stuff look easy. You deserve a professional in your attic!

3.  All of the attics that we insulate are vented attics. Therefore, the moisture we added to your cellulose attic insulation wicks its way to the top surface of the cellulose and evaporates into the atmosphere through the passive ventilation in the attic. Physics at work 24/7!


4.  Odor disappears quickly! After installing over 6 million pounds of stabilized cellulose attic insulation in existing homes, we’ve learned that generally it takes about two sunny days following our install date for the moisture to evaporate in a vented attic in our  Atlanta market.

5 Conditions that affect how long it takes for the “wet paper” odor to disappear:

  • Cloudy & Rainy conditions will prolong the evaporative process in your attic. Add a sunny day for each rainy day. So it may be three days before your odor disappears.
  • Super high humidity. If we’re in the “dog days of summer”, you can expect it may take a bit longer (extra day or two) before you no-longer smell your insulation. Especially if you have a surprise afternoon rain shower.
  • Cold AC temperatures inside the house. I know this appears strange to some, but when you keep the temperature “low & cold” (immediately following your install date), in the living space directly beneath the attic, it can prolong the evaporative process in your fresh attic insulation. It’s physics… moisture is drawn to cooler temperatures, (your sheetrock ceiling has a lower temperature) vs the warmer air in your attic. So, if you have a choice, leave the AC on a higher setting for the first couple of days immediately following your installation of fresh stabilized cellulose insulation. This will speed-up the evaporative process and you’ll have physics working for you … the moisture will more easily “wick” upward into the warmer temperatures in your attic, and pass into the atmosphere!
  • Pre-existing attic insulation. When we install our fresh stabilized cellulose insulation over top of a layer of pre-existing attic insulation – those homeowners rarely if ever mention that they experience a “wet paper smell”.  This is because the thin layer of existing attic insulation “isolates” the fresh cellulose insulation from contact with the cooler sheetrock. In fact, I do not have a single memory of a “bump-up” client mentioning an odor.
  • Attic ventilation. A properly ventilated attic allows for quick evaporation of the tiny amount of moisture we’ve added to your insulation! Generally speaking, a ridge vent with soffit vents is the best passive ventilation system in our Atlanta market!

Is the cellulose odor dangerous, or is it negatively affecting my health?

The odor from your cellulose insulation is harmless. Remember, there are only two products in our insulation: paper and boric acid. Neither are dangerous to your health in the quantities we have installed in your attic.

On average we add 1 gallon of water for every 60 pounds of cellulose attic insulation. If a bale of cellulose insulation weighs about 25 pounds, it’s about one gallon per 2.4 bales. Hardly much to be concerned about. And the boric acid protects against any mold or mildew organisms that try to live in your insulation.

In Conclusion

Not a single Atlanta homeowner, since my first install in 1998, has ever asked us to return to their home and remove their cellulose attic insulation because of an odor.

Odor from stabilized cellulose insulation is a very minor occurrence. It’s rare, and when it does show up, it’s faint and short lived.

And, after the 2 to 3 day evaporative process is complete, the faint odor never returns. Not a single Atlanta homeowner, since my first install in 1998, has ever asked us to return to their home and remove their cellulose attic insulation because of the odor.

And then, if your nose is like mine – it may find something else to draw your attention to!

Thanks for reading. I hope this has helped.

God Bless You!


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