Ok, first, welcome to the forum!! There is no such thing as a dumb question! The only dumb question is the one not asked. You may have to remove the cabinets as there is a piece of plywood above the cabinets that is nailed or screwed to the overhead rafters. If you need to replace the ceiling all the way, Then you may have to remove all the metal on the roof to replace the rafters. The rafters usually are screwed to the walls. On most, there is a trim piece that goes all the way around the roof of the trailer. remove that and the roof is just a single piece of sheet metal. There are ribs that are spaced for a 4X8 sheet of Headliner. Its usually wood with a plastic coat. Make sure you have the new rafters at those spacing and you just use liquid nails to glue the ceiling to the rafters. The interior walls and closets are actually the main support for the ceiling. but there is plastic runners to join the panels. I will add a couple of pictures for you at the picasa site. I would get rid of the metal roof over rubber membrane. That's just me. You asked about the snow and weight, If you have a ladder on the trailer, then it most likely has 16" spaces on rafters, and wood roof under the metal. If not it still may have plywood which could still support you and any snow that is on the roof. But the metal is not supported and by itself is not capable of supporting much weight,(including you!). It would look like it sags in between the rafters. If that latter, I would add a plywood roof under the metal or rubber membrane. That's a start and all i can say is have fun!! If its not, then i would go a different way. Dan
The pictures are in a folder marked Ceiling Pic's. I put them on line for you and i used the Nikon instead of the phone camera so you can blow them up. if you notice there is a bit of waviness to the ceiling but that's because the walls are the only thing holding it up. I could have used more support when glued. Sorry, My fault...also need to be vacuumed again. The dust is showing up again from the heater fan on the a/c unit. later....