How does condensation affect a false ceiling?

Condensation can form for the same reasons it does on Windows, if one side is colder than the other.

Condensation in extreme cases can make a false ceiling wet and soggy.

In mild cases it just tends to increase the chance of sagging as the moisture absorbed often makes the material less rigid and sturdy so it doesn't stay in place perfectly.

There is also the risk of mold and mildew growth if the area remains perpetually wet all the time.

To prevent this, most false ceilings include adequate ventilation and air circulation to prevent moisture build up in a localized area.