On 17/10/2012 22:50, GMM wrote:

Did the OP ever say exactly what his current joists were?




The simple answer is there aren't any - apart from the skinny (3x2 or so) ceiling joists. Since these are 150 years old, I wouldn't walk on them without care, let alone base any kind of structure on them.


You'll be walking on those when you do the work. Will you support them
temporarily?