I am considering cellulose insulation, but surrounding myself with borate has stopped me. I need to insulate walls, eaves, and roof peak.

Asked by Mary Gattis
Reading, MA

My 1930 era home has some foam board within the upstairs walls, scattered batts of fiberglass and/or cellulose in the eaves, no insulation downstairs, and unknown insulation in the peak of the roof, probably a little fiberglass. Exterior siding is vinyl, in good condition. Roof is new. I'd like to have insulation blown in, as the interior walls are also in good shape. I had considered having borate-treated cellulose blown in by contractors who said they could remove strips of siding, but I have auto-immune problems, and the idea of surrounding myself with borate has stopped me. Would aircrete be a solution? Are there better green/health solutions?


Polly Osborne, FAIA, LEED AP

Answered by Polly Osborne, FAIA, LEED AP

Los Angeles, CA

Polly Osborne Architects

July 12, 2013

Dear Mary,

I know it might sound crazy, but you could try sleeping with some borate treated insulation next to your bed. A home test will show you what your sensitivity to the material is. Most people are not sensitive to borate.

  • Borates in cellulose are used as a fire retardant.
  • I recommend avoiding the cellulose with the less expensive ammonium sulfate as a fire retardant. That is much more likely to give you trouble.

I can't comment on Aircrete because it isn't approved in my area, so I've not gotten to use it.

I would avoid polyurethane spray insulation. If it doesn't cure properly, its toxins will not become inert.

For areas where batts make more sense than cellulose, I would recommend Bonded Logic’s “Ultratouch.” This has been a good product in every application I’ve used it in and not one client has reacted to it.


For more information:

Read "What distinguishes one cellulose from another? I've noticed a very wide range of pricing for packaged cellulose and don't understand why." a Q&A answered by Polly Osborne.

Tagged In: cellulose insulation

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