Blowing Cellulose Insulation into an Old Attic with Flex Ducts
Hello! I have a home in northern NJ built in 1895. It has a pitched flat vented roof. The roof is made up of torched down bitumen material. The attic is accessible from the front of the house and pitched to the back. I wanted to insulate the attic (currently uninsulated!) with blown in cellulose. The floor of the attic is the ceiling of the second floor that has plaster and lath. I have two issues that I am wrestling with. One is that there is a furnace in the attic with several flexible ducts that run throughout the front and the back of the attic. The ducts are only used for heating and no cooling. I have no plans for adding a cooling system (maybe a Fujistsu minisplit on the second floor later). Will it be okay to blow cellulose around and underneath the ducts but not totally embed them in the cellulose? I have read several articles that recommend to totally embed them but I don’t think it’s possible to totally embed all the ducts. The other issue is will the 125 years of floor beams hold up the weight of the cellulose. Currently the beams are not sagging.
First attached picture is of the floor and ceiling of the front of the attic. Second picture is of the big return duct and smaller supply ducts. The floor here foil bubble sheet material. Thank you for your input!
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