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Community and Q&A

Blown/Compact Rock Wool

ermackey | Posted in Green Products and Materials on

I live in Juneau, Alaska. Being in a Temperate Rain Forest (220+ days of rain per year), both rain and cold is an issue. I would like to retrofit my exterior walls and blown cellulose seems like the most effective way per dollar spent. However, Rock Wool seems like an even better choice since it provides better fire resistance, moisture resistance, and a similar R-value.

The problem is that I can not find any USA granulated Rock Wool. I find plenty in the UK and New Zeland, but nothing in the USA.

#1: Where do I find granulated Rock Wool or Rock Wool adequate for blowing into wall cavities?
#2: Are there any downsides of which I need to be aware?
#3: Any other tips or considerations are appreciated.

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  1. GBA Editor
    Martin Holladay | | #1

    I have never heard of a U.S. contractor who offers blown-in rock wool, even though I know that the process is technically possible and has been done. The method may be used in commercial construction, but I've never heard of it being done on a residential job in the U.S. or Canada.

    Here's my advice: if you can't find the product in Juneau, I wouldn't waste a lot of time (or invest in high shipping charges) to get a few bales of mineral wool shipped to Juneau. I would select a type of insulation material that is readily available in Juneau.

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