Expert: Bruce E. Johnson - 1/17/2010

Question
Hi,
I have a 2 family cinder block salt box. The sheet rock is attached to firring strips.  There are no 2x4's or framing.  The moisture comes right through the walls.  My real problem is the attic and my ceiling on the second floor. The attic floor is insulated.  I have exhaust fans on each side of house and 2 roof vents. The attic is just a crawl space.  The hatch is in my bedroom closet.  The moisture drips from the ceiling and the closet is full of mold. There is condensation on all my windows on the second floor (not on the first floor)  I have a rolled rubber roof on an almost flat attic crawl space. I thought I took care on the problem with new insulation a few years ago and a new rolled rubber roof but the problem still exists.
Please help.  It seems that everyones suggestions do not pan out.
Thanks
Darlene

Answer
Hi Darlene, it sounds like you have too much ventilation in the attic.  More and more architects are getting away from ventilated attic space for this reason.  Especially in humid climates, the ventilation pulls in the moist air and there is no way to treat the air to remove the moisture so it accumulates.  If you haven't already you should insulate your rafters.  This will keep the heat exchange between the roof and the attic to a minimum.  Once your attic roof is insulated and the area has been dried out to an air moisture content of less than 50% you should close off the ventilation completely (temporarily) and see if this stops your problem.  If it does, you can remove the ventilation equipment or seal it off permanently.  Once your attic becomes a part of the heated/cooled house envelope and you aren't pulling all that moisture into it you should see results.  Also making sure the attic windows or eaves are properly sealed and caulked will help with this system.  I hope this information helps, please feel free to write again regarding this or other matters, sincerely bruce e johnson..bejohnsonconsulting.com