Advice needed, we have a timber floor in lounge and has become bouncy in the alcove. a joiner came round to assess it and says once joists are replaced he will replace my floorboards with green moisture chipboard.... is this allowed to be used downstairs as i know newbuilds have chipboard upstairs. im happy with the chap who came about replacing joists etc. i just want to be sure chipboard can be used downstairs before i let him proceed with job. advice appreciated