Hello, I bought my first house two years ago which was built in 2005. The biggest issue I've faced since moving in is that the vast majority of the upstairs floor creaks to such a degree that it bothers me daily. My initial research led me to think that it be a case of fastening the boards down or replacing nails with screws but sadly it's turned out more complex. In pulling up the floor in two rooms so far, have found that the joists are 220x44 spaced at 400, floorboards