Forums DIY House insulation improvements? Reply To: House insulation improvements? May 9, 2018 at 9:58 am #202 nab 23 Posts If there’s crawl space under your floor you don’t need to pull it all up but it’ll be a grim job that might involve a bit of tunnelling through walls/piers supporting the floors at mid span. Helpfully someone has already done this in mine, unhelpfully it’s below the local water table making for a difficult work environment!