Interior moisture issue?

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Jun 23, 2020
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Brooklyn Park, MN
Lots of info before the question. I have a low pitched (around 3/12) rambler manufactured home built in 1969 that has cathedral ceilings, looks like some paneling similar to sheetrock is attached to the bottom of the roof RAFTERS (no trusses). The kitchen area, the area above the bathroom, central hallway and the closet at the house entryway have closed in dropped (not sure if that is the proper term)ceilings that allow dead air space. Roof was supposed to be two years old when we bought the house (as-is from hack home flipper), but the roof was rotted and spongy after 12 years, mainly around the bathroom. The house flipper remodeled it and never hooked up the bathroom vent and just let it vent into the dead airspace above the bathroom and into the roof thru the hole in the paneling attached to the paneling under the rafters. Two years ago I had chose a contractor that suggested ripping off the decking and use closed cell foam insulation as it will act as a vapor barrier since the only one I had was crumpling away on the fiberglass insulation in the ceiling. They ripped off the decking and added 2x2 strips on the 2x6 rafters to get me in the r30 range after spraying. Then they added a ridge vent instead of the three turtle vents we had.

Fast forward to this late spring and a couple of issues exist. First showed up last year that a few areas have the 2x2 sections slightly lifted, one more so, and that one is likely due to a vent (likely was an old range vent) that was never pulled and sealed up and the roofers put a turtle over it. I asked what that vent was for and they said there had been a vent pipe. I had no idea what it could have been for, so I shrugged it off. Well, last year (roof one year old) called the contractor and told them about the raised section and they looked at it and didnt know why it was raised like that. They said they would fix it, but they first wanted to find out why this happened. Winter came and it was obvious there had been heat loss in this area along with the area by my front entrance. There is dropped ceiling with dead air space by my entrace, but maybe also could be a door not the best sealed leaking warm air up into the soffit?

Anyway, fast forward to about a month ago I noticed mold growing on an interior wall in my main hallway, the bathroom shares this wall, and damp to the touch on the bottom 10 inches in parts of that wall. I freaked out thinking it was a roof leak, called the contractor, they came out and looked things over. The one area that is obviously raised on the roof looks to be an old range vent that was never pulled out or sealed off properly, so he is thinking that is what caused the roof issue, and needed to be removed. Then he asked if the damp wall occurred before the roof and spray foam insulation, and I said no. He suggested using a dehumidifier for the time being. I used vinegar to clean up the mold and put the dehumidifier in the hall for two days, then moved it into the bedroom across the hall and set it to 60% and have not had any damp feeling to the wall since. The wall opposite in the hall had no damp feel to it, and that wall is shared by a bedroom with no dropped ceiling with dead air space, but the damp wall is the side shared with the bathroom with the dead air space. Funny thing is my bedroom shares a wall with the bathroom, and in my closet ceiling there is open space that is the dead air space above the bathroom, in other words the wall of my closet does not go all the way up to the cathedral ceiling , it is open from the top of the framing of the false ceiling up to the cathederal ceiling. I don't have a closet door so it is always open, but mind you the opening to the dead air space is not much more than maybe 12" tall at the edge of the closet opening.

The contractor told me they want to spray insulation foam in the dead air spaces and any of the dead air spaces that they add insulation to, he will need to cut out the foam at the ridge to allow the heat to vent through the ridge vent. All the vaulted ceilings will stay as they are. It’s just the dead air spaces they need to insulate and vent out at the peak.

My concern is two things, one is if they fill the area with foam, will that not create two vapor barriers if it is not completely filled up? If they fill it all up, will it be a non issue? I asked if they planned to fill it completely up and am waiting for a reply. My house is full electric so we do not have a furnace, but previous owners had central air installed at one point and I have ducting up in that area above the bathroom, and might want one again and need that space to run the ducting so I might have to cut access to those areas and hook up all the ducting again (has been moved around and disconnected since it has not been used). But one concern is how safe is it to spray foam all around the bathroom vent fan and wiring up there.

Does what the contractor plans on doing sound like a sound choice? Is the dead air space likely causing the damp wall? Has anyone seen anything like this before? Also, any idea why the firred out 2x2's on a few rafters might be lifting?
Need some advice before I let him proceed.
thanks in advance to anyone with the knowledge that is willing to give your views/opinions on what might be happening.
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