Mobile home was re-roofed in first 1/4 of 2009; single story mobile home with 3T & 15# @ a 1/2 lap. None of the old felt was removed with 2 or 3 sheets of OSB (non foil face) replaced.
Mold growing in the bathroom, excessive moisture & condensation showing on the exterior of the shingles for around 9 of the 12 turtles exhaust vents - they are a combination of round & square vents.
Affected areas are ONE of the bathroom exhaust pipes & the two bathrooms are around 45 ft. apart (the other bathroom exhaust pipe doesn’t show any mold… black spotting… where one bathroom exhaust vent does).
Interior sheetrock seems to be sold & firm for the affected bathroom.
The vent setup was double checked after the reported moisture issues & it’s fully intact with no issues.
This mobile home is about 9 years old, it has about a 6" soffit with a continuous venting design (can’t guarantee it’s not blocked with some kind of insulation as no visual inspection has been performed). Insulation is a blown in variety (not rolls or batts) & when the roof was partially opened up to check the bathroom vents for intact, the insulation appeared dry.
The air conditioning DOES duct through the floor & NOT the attic; he said it was pretty humid in the house when he inspected it & the air here in Central Texas was listed @ around 80% relative humidity according to my web search.
I’ve already given him the business for not taking any photos…
since it’s showing up around so many of the vents I would guess thar when they blew the insulation they blocked most the soffit vents, are the 3 unaffected vents in the same area as the bathroom with no problem? Could be that area is getting enough air flow to stay dry while the rest isn’t, somthing like that with the venting is the only thing I can think of without actually seeing it
lety me add to that, most mobile style homes have the insulation so you can not properly ventilate the roof. In other words he is well screwed, have to pull all the decking off, put baffles in and the put the deck back on and shingles. then you can ridge vent the thing and the problem is solved. As far as bathroom vernt they all must be ventilated it could be traveling if exhusted in attic, also check if they have a fan in kitchen that will also go to the attic. We all know hot showers build steam and will condinsate. Hence mold. Thats how i bid and do the. Hope this helps. God bless.
If I were specifying the ventilation, I would use a drip edge eave vent on the gutter edge. Cut ventilation holes through the doubled center wall and install as many power vents as required for the attic area.