Is it possible for there to be enough condensation on a copper or cast iron roof drain pipe to cause enough dripping so that it looks like the roof is leaking? Drywall is stained and water is dripping, but it is sporadic. Doesn't always leak when it is raining.

1. uninsulated ceiling space
2. flat roof copper spun drain.
3. I will assume copper or cast iron drain pipe as it is fairly old commercial building
4. outdoor temps are between 0 and 5 degrees celcius
5. No plumbing pipes in the ceiling space.

if this is not likely then roof must be leaking from somewhere.

thanks for any help/advice. sorry if this is the wrong section.