(Sorry about the last blank post, which was an accident.) Anyway, my
problem is there is mold growing in my attic, primarily on the ceiling,
underneath the roof sheathing, and mostly on the side of the attic in which
the roof is facing the north. I'm looking into getting the mold cleaned up,
but it seems to me I need to have the ventilation issue taken care of first.
A roofer looked at my roof, and doesn't think there are any active leaks.
My roof is less than 9 years old.

My attic is a crawl space that is around 1000 square feet in size, and I'm
guessing that it's maybe about 4 feet high at the center. There are two
gable vents; one on the east side and one on the west side. There are two
passive square vents near the ridge of the roof. There is almost no
ventilation at the soffits, that is, my attic does not have soffit vents,
and, although there are a couple of little places where I can see daylight
near the eaves, this doesn't amount to much.

A roofer is talking about installing another roof vent with a temperature
controlled fan near the center of the roof near the ridge. I'm just
wondering if doing so would be helpful, or would it turn out to be no help,
or problematic? My fear is that the fan might just draw air inward from
the two closest vents, which are the existing square passive roof vents. Am
I incorrect in suspecting this could happen?

My understanding, is that the consensus on the internet is that the state of
the art in attic ventilation is to have continuous soffit vents with a
continuous ridge vents. Since my attic currently already has two gable
vents, plus two square passive roof vents. I'm just wondering if switching
to the ridge/soffit system would be the only real solution to my attic mold
problem, or if there would be a way to improve upon my existing ventilation
system (such as a installing fan). Any ideas. Basically I need to ensure
that whatever I have done ventilation-wise is going to be a real improvement
which results in mitigating the chances of mold growth. Any
recommendations?

Thanks.

Jeff