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Jason Fox
Writer / DIY Homeowner
Asked a question 5 months ago

Is dense packed cellulose insulation a good air-barrier for a Passive House project?

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Ed May
Partner, Building-Type LLC

Hi Jason, 

I wouldn't rely on your denspack cellulose on its own to provide airtightness to the Passive House levels. While it's certainly true that denspack cellulose will help your airtightness overall, that kind of insulation should always be coupled with a true air-barrier material such as plywood, specialty air-tight membranes or the like.

We typically like to couple denspack cellulose with a purpose-built airtightness membrane which can double as the 'netting' to hold the cellulose in place. Seems to work pretty well overall.