I have a townhouse where I have removed the old floor; the house was built in 1956. The design is a crawl space with concrete + felt + insulation / joists.
I plan to lay new felt and stone wool insulation, leave the old joists in place, and then cover with chipboard flooring.
My question: What is a suitable underlay felt between concrete and insulation? Do I need felt at all, and which variant is appropriate?
