I think I have some condensation on a ceiling.
Patches of mold have formed and water can be seen on the surface, similar to condensation on a window.
This is forming immediately below a steel joist at the roof apex, there is little or no roof void above, just the ridge tiles.
I believe there is no insulation between the ceiling and the joist, the ceiling is cold to touch relative to areas away from the joist.
How can I confirm it is condensation and not a leaking roof.
