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BIBS vs. dense-packed cellulose

welivehonestly | Posted in Green Building Techniques on

The debate rages on, or maybe in most folks’ minds it’s been settled. I still haven’t decided, for our Zone 7 project.

I like BIBS because I believe it should be less prone to settling, but has a higher embodied energy with less recycled content.

I like cellulose because it is getting so common, includes borate to repel ants (and mice??) , but I believe may also contain flame retardants I am not too excited about. Also as an engineer/scientist I can picture it settling or holding onto moisture, but only on a theoretical level, that is not based on experience.

What are your thoughts?

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  1. welivehonestly | | #1

    seems like this answers it pretty well:

    Anyone still using BIBS? If so, what is your rationale?

    1. Expert Member
      MALCOLM TAYLOR | | #2


      Dense-Packed cellulose for walls is still rare here, and until that changes, installers have developed the experience necessary, and established a good track record, I wouldn't be specifying it. That may be a regional concern, but it may still be quite a common one.

      In the discussion you linked to the question of settling was dismissed as being solved, but in the blog Martin published today it appeared to be a factor in the problematic roof assemblies BSC were testing.

      What are the advantages of batt insulation?
      - Easy visual inspection.
      - DIY friendly.
      - Much easier to make modifications or renovate in the future.
      - Better fire resistance.

      What BIBs doesn't do is hold water, which can be a negative, as cellulose can provide beneficial moisture-buffering in cavities.

      Both types of insulation appear to perform well if installed correctly.

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