Blown cellulose or blown mineral wool?
I’m in the process of adding some more insulation to my attic. It’s about 700 sq ft, 2×6 construction with 2 layers of fiberglass batts. I live in Zone 5-6, southern NH. So far I’ve lifted up all batts and have sealed up holes around wiring and fixtures with great stuff foam. I’ve also installed vent extenders over every soffit opening. As far as I can tell my attic is very dry and well ventilated. I saw no evidence of water damage when up there. I was planning on blowing in cellulose insulation with my buddy and then I got carried away reading negative things about this material. Now I am concerned that maybe this isn’t a good choice for blowing in on top of existing batts as I’ve read concerning things about moisture absorption etc.. Is this a warranted concern or not?
I’ve also looked into blown mineral wool but it’s about twice as expensive as the blown cellulose. I’m also not sure that I can use the same rental blowing machines to blow mineral wool which would be an issue.
Any advice would be greatly appreciated. I’m willing to spend more money if it’s worth it, but I also know that I may be over complicating a simple thing here.
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