My new construction will be getting dense pack in the walls. I’ve been looking at National Fiber’s
Cel-Pak which is an all borate cellulose and advertised by National as being comprised of over-issue newsprint. In a nutshell, they describe it as “the cleanest cellulose insulation you can buy”. Though I do like the all borate aspect and am not a fan of ammonium sulfate in insulation, is Cel-Pak worth the higher price? Is the lack of glossy ad paper and post consumer recycled material going to have measurable advantages? If the price difference was negligible there would be no question which product I’d use, but having received two bids for my project, one using Cel-Pak and the other not, the difference in price is large.
Thanks for your thoughts.
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This is a judgment call. I think that it's fair to say that cellulose with ammonium sulfate would not be on the market if there were widespread problems with the product. The vast majority of owners of homes with this type of cellulose are quite satisfied with the product's performance.
It's my understanding that the few reported problems with ammonium sulphate have to do with wet cellulose. Of course, if you have a water-entry problem -- a plumbing leak or a major roof leak -- you've got a big problem no matter what brand of cellulose you have selected.