We have an old house from 1920. We've had very cold wooden floors and have now torn them up and shoveled out all the sawdust. We have a crawl space underneath that is dry. In the joist space, there are a few gaps visible. We are going to use cellulose fiber as insulation, but now we wonder what type of fabric or material should be used under the insulation? The sawdust was dry and presented no problems. Currently, there's a bit of draft through the joist space. I've been advised to use rag paper at the bottom before the insulation if the sawdust is dry, as it minimizes impact. What do you knowledgeable builders say? What should we use under the insulation?
