Due to the discovery of asbestos, I am removing and replacing all ducting in my attic.


Due to the discovery of asbestos, I am removing and replacing all ducting in my attic.

Asked by joann

Also, is there a non-toxic alternative to fiberglass insulation?

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Polly Osborne, FAIA, LEED AP's picture

Dear Joann,

I am glad you are removing the asbestos.Here are some thoughts besides the toxicity of the insulation, which I'll also address.

Asbestos removal

Have the asbestos removed professionally. Amateur removal can cause serious health risks. Removal must be complete, leaving no scraps.

  • Complete cleaning of connecting parts that are to remain is very important.
  • Obtain documentation from the removal company insuring they have done this properly.

The National Institute for Standards and Technology (NIST) has a list of accredited laboratories. Their phone number is (301) 975-4016. Asbestos removal contractors are licensed by each state.

New ductwork

Be sure your attic is well ventilated, or that the attic insulation itself is installed against the outside envelope of the house. If that is done, then the ducts are within the heated envelope.

  • Avoid moisture infiltration into the attic and ducts.
  • Be sure the ducts don't leak and are clean.

Ducts should be installed so as is to be sure they are sealed from leaks, and that they are clean.

  • Ducts should be tested for leaks and cleaning should always be done after installation.
  • Installation should be done properly to insure no bunched or crimped places and no gaps.

Insulating your ductwork

Ultratouch. My personal experience with non toxic brands of insulation have led me to a favorite. It is "Ultratouch" by Bonded Logic,made from blue jean scraps. They make a duct insulation. I have had good luck with this company.

They claim their insulation can be used in a non-vented space, and I have tried that with success. But non-vented attics can cause moisture build up, and I notice the Green Home Guide staff in their excellent article "Buyer's Guide to Green Insulation" do not recommend it for moisture prone areas. This makes sense, as it is made of cotton, which absorbs moisture.

  • If your attic is properly ventilated, this may be the insulation for you.
  • It is more costly than most and some contractors complain it is more dense and harder to cut, so if you are on a budget there are other options you can consider.
  • (If you have a whining contractor, just remind him he's going to be healthier installing this than fiberglass!)

EcoBatt.EcoBatt glass wool is an option that eliminates the phenol, formaldehyde, acrylics and artificial colors of traditional fiberglass and uses recycled glass in its manufacturing. It is less expensive than Ultratouch.

Nest Insulation is an insulation I have no familiarity with but it claims to be waterproof and non-toxic. I could not find enough information on it to comment here.

The various spray insulations for ducts are costly and some sensitive people have had trouble with them. I have only used them a few times and am not a fan.