Doing a full gut - leave attic cellulose insulation or replace?

[Account Closed]

I'm fully gutting a single family house. I have the lathe and plaster out of the finished attic and there is a ton of cellulose insulation behind the walls. Should I leave it in place or dispose of it and replace it? The house has a lot of mold so I am a little worried about moisture in the existing insulation.