The condensation occurs most commonly on the roof as the warmest most moisture laden air rises to roof level.
Steel roof sweating.
This is often accomplished using vinyl backed fiberglass insulation to prevent humid air from coming into contact with the cooler metal roof which may be at or below the dew point.
Traditionally condensation is managed by insulating the metal roof so that the panel temperature never reaches the dew point.
If the tin roof sits on top of another material such as wood then you can get a case of wood rot.
Metal gets cold faster than other items so condensation begins on metal first.
At night the thin metal in the roof quickly cools down.
Put the steel down directly on a vapor barrier.
The result is the roof sweating and dripping water all over your precious stuff.
Metal roof over shingles condensation.
Metal roof sweating is a result of excess humidity condensing on the underside of your roof.
Ok now we understand a bit how the condensation in metal sheds happens.
Warm wet air rises and meets the cold roof and cools.
When the temperature of the roof is lower than the air inside the extra moisture in the air condenses on the underneath of the roof.
Metal roofs must be laid flat on a vapor barrier because steel will condensate if there s any air space underneath it.
As it cools it can t hold as much moisture.
The prime reason for this is due to the temperature differential between the inside and the outside of the shed.
Essentially condensation occurs at night when the temperature inside a building is warmer than outside.
Metal roof condensation especially with a tin roof can cause serious problems when the metal sweats or rainwater collects under the tin panels when this happens the tin roof can rust and even warp.
Picture a cloud of moisture floating overhead between the rafters.
Condensation happens when moisture filled air contacts anything that is below the dew point temperature.
It doesn t matter if the air space is a half inch or six inches because the condensation factor will remain the same.
Condensation on metal roofs can be a problem once the weather starts to get cold.
That excess moisture ends up as drops of condensation on the roof.
Metal roofs are known for this with condensation forming particularly at the beginning and end of a day.