Condesation in Ceiling

[LabFolk]

I have an older mobile home in Wisconsin that I use as a weekend get away. It has a flat metal roof on it. Last fall I tore down the ceiling, vapor barrier and insulation in a bedroom that had previously had water damage but no longer leaked. I added unfaced R-13 insulation, a plastic water vapor and a plywood ceiling. I then shut the trailer down for the winter. When I opened it up this spring the plywood was covered with mold, the plastic water vapor had trapped water in it and some of the insulation was soaked so I tore down everything again. It poured that day and there was not a drop of water inside so I'm still confident there are no leaks. The next day it was cold so I turned on the furnace and the room turned into a rain forest with all the condensation on the inside of the metal roof so I feel that is what happened over the winter. There is no ventilation in the roof or sides. There are no mobile repair persons in the area so I called an insulation company. They want to block off the attic with plywood from other rooms in the home and then spray 3 inches of insulation for about $500. He swears that will fix the problem and I don't need any ventilation to prevent condensation. Anyone have an opinion whether this will work or any other suggestions? I don't have a clue what else to do.

Thanks for you help.
Jerry

[Greg]

The theory works on paper. Is he willing to put it in writing? If so I would go for it.

Greg

[JoeHenry]

Iv been having the same problem for a few years.Had to tear out the hallway ceiling and reinsulated the attic.I have a cathedral ceiling in the living room so theres no space between ceiling and roof.I put a vent on the one end on the outside for the back half of trailer and fixing to put another on the front half of ceiling.I think it helped.I seen a difference last winter.There was still a little condensation but not as much.When I put the other vent in it mite take care of it.I also going cut a door in the ceiling so I can have acess and see the metal from the inside. Iv even thought about putting a dehumidifier up there sometimes. Work in process I reckon.

[LabFolk]

What type of vent did you put in the ends? Thanks.

Jerry