There are only 2 joists, one at the edge of the floor and one approx 1.5m in from this. These joist are 6x3 inch The floor is quite solid, except for near the edge as this joist is quite rotten. The floorboards are full length and about 2 inch thick.
So I could just replace the rotten joist, this would leave me with a nice solid floor, especially as I am putting some stairs in to the currently inaccessilble basement so could implement some sort of upright support.
Would you add extra joists?
And/or... There is only just enough height so if I could replace both joists with more numerous but smaller joists it would be of benefit.