Steel Roof Sweating

Metal roofs are known for this with condensation forming particularly at the beginning and end of a day.

Steel roof sweating.

Put the steel down directly on a vapor barrier. 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. 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.

Metal roof over shingles condensation. Ok now we understand a bit how the condensation in metal sheds happens. The condensation occurs most commonly on the roof as the warmest most moisture laden air rises to roof level. Metal gets cold faster than other items so condensation begins on metal first.

Warm wet air rises and meets the cold roof and cools. At night the thin metal in the roof quickly cools down. Picture a cloud of moisture floating overhead between the rafters. The prime reason for this is due to the temperature differential between the inside and the outside of the shed.

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. When then environment outside becomes cooler i e. As it cools it can t hold as much moisture. Metal roof sweating is a result of excess humidity condensing on the underside of your roof.

That excess moisture ends up as drops of condensation on the roof. Condensation happens when moisture filled air contacts anything that is below the dew point temperature. If the tin roof sits on top of another material such as wood then you can get a case of wood rot. The cold metal in contact with the warm air means that water droplets condensation forms on the inside surface of the shed roof.

Metal roofs must be laid flat on a vapor barrier because steel will condensate if there s any air space underneath it. It can lead to roof leaks even if rain has not occurred for several days. 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.