Condensation on metal roofs can be a problem once the weather starts to get cold.
Steel roof sweating.
Put the steel down directly on a vapor barrier.
That excess moisture ends up as drops of condensation on the roof.
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.
The condensation occurs most commonly on the roof as the warmest most moisture laden air rises to roof level.
The prime reason for this is due to the temperature differential between the inside and the outside of the shed.
Metal roofs are known for this with condensation forming particularly at the beginning and end of a day.
Picture a cloud of moisture floating overhead between the rafters.
Warm wet air rises and meets the cold roof and cools.
If the tin roof sits on top of another material such as wood then you can get a case of wood rot.
It doesn t matter if the air space is a half inch or six inches because the condensation factor will remain the same.
Essentially condensation occurs at night when the temperature inside a building is warmer than outside.
Metal roof over shingles condensation.
Metal gets cold faster than other items so condensation begins on metal first.
Ok now we understand a bit how the condensation in metal sheds happens.
When then environment outside becomes cooler i e.
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.
Condensation happens when moisture filled air contacts anything that is below the dew point temperature.
Metal roofs must be laid flat on a vapor barrier because steel will condensate if there s any air space underneath it.
Metal roof sweating is a result of excess humidity condensing on the underside of your roof.
As it cools it can t hold as much moisture.
It can lead to roof leaks even if rain has not occurred for several days.
The cold metal in contact with the warm air means that water droplets condensation forms on the inside surface of the shed roof.
Traditionally condensation is managed by insulating the metal roof so that the panel temperature never reaches the dew point.