Moisture condensation can occur on the metal roofs of mobile homes for several reasons, including high relative humidity inside the mobile home and poor air exchange rates. Signs of condensation on the roof include brown stains on the ceiling, wood rot, mould growth and musty odours. Fortunately, there are some things you can do to stop condensation in your mobile home metal roof.
Install a vapour barrier, sometimes called a moisture barrier or ground-moisture barrier, under the flood of your mobile home. Vapour barriers should have a perm value less than 1.0. Common vapour barriers include polythene film and asphalt-coated papers.
Reduce indoor humidity. A dehumidifier works well for this. In addition, many dehumidifiers come with a humidity gauge so that you can keep track of the relative humidity in your mobile home. As an alternative to running a dehumidifier, consider hanging packages of chemicals that absorb moisture (such as silica gel) in your mobile home or running an air conditioner.
Seal air leaks in the ceiling and walls. Air leaks can often be identified by small stains on the walls or ceilings.
Check to make sure all appliances vent to the outside. It's not unusual for a bathroom fan to be vented directly into an attic of a mobile home, causing condensation on the roof.
Increase circulation. Stopping condensation from occurring on your roof can be as simple are increasing circulation inside your mobile home. Consider opening windows and running a fan or installing an exhaust fan, particularly in areas with high moisture, such as bathrooms and kitchens.