Expert: Daniel Humphrey - 3/22/2009

Question
In case of a pitched roof with steel sheets in a hilly terrain,how best one can protect against appearance of water droplets on the false ceiling.
Regards
Liaqat Hayat

Answer
Dear Liaqat,

As you probably know, the water droplets appear whenever warm, moist air contacts a surface cooler than the dew point. There are three ways to prevent condensation:

1. Reduce the moisture content of the warmed air;
2. Warm up the contact surface; and
3. Prevent the moist air from reaching the contact surface.

Reducing the moisture content can be done by ventilating, dehumidifying, or cooling the air. This may also mean

Warming up the surface can be done by exposing the surface to heat, or insulating the surface from the cold and allowing the room air to circulate freely over it.

In your case, with a metal roof, the ceiling is not insulated enough; or the moist air is getting behind the insulation and dripping from a cold surface. Add another layer of insulation and look for ways to seal the air leaks in the ceiling.

I'm sure that once you study the problem, you will find some solutions that help.

Regards,

Daniel