I have read most of the posts pertaining to my issue, but still have a
few questions unique to my situation. I live in Michigan and have
recently added an addition off the back of my two story tutor home.
The existing second story roof pitch was continued rearward to create
the addition roof. It is a 12:3 pitch--not very steep. The existing
attic appears and always has appeared very dry to me. It has about
3"-4" of blown-in insulation. It has two side vents and two roof
vents. There is a bathroom fan on the second floor but I have it
vented into one of the side vents.
Because I extended the existing roof pitch onto the new addition it
created very little space for insulation and air venting. I put soffit
vents along the entire eave/over hang. I then put those plastic air
vents from the soffit all the way into the existing attic space. I
then put 5-1/2" R-21 insulation with vapr barrier facing the interior.
Because I am working only with the depth of the joist I literally have
roof board/air vent/insulation/drywall all stacked on top of eachother.
The only air gap is the one created by the plastic air vents.
I was getting ready to drywall when I noticed serious condensation on
the flanges of the air vents--the area where you staple. The area of
the air vent that is off of the roof is dry but where the flange goes
up to contact the roof board it is really wet. Not just like a little
condensation where you could write your name, but like many big drops
of water. My insulation was wet. I have ten "runs" and they all have
this same condition.
Any suggestions on how to resolve this issue? Somebody told me that I
need to have equal amount of inlets as I have outlets. I probably have
more inlets then I do outlets. Should I install an attic fan? I was
reading about a solar powered one, which means it only operates during
the day, would that be sufficient?