Ongoing attic moisture problem

I live in northwestern PA. I've noticed mold and moisture in my attic. Started with wet insulation and rotting attic floor. We have since removed EVERYTHING down to bare ceiling joists. We sealed all cracks and holes we could find. We installed 12 inches of insulation with vapor barrier towards living space, since we only had 6 inches originally. We raised the floor to accomadate this, using 1/2 inch OSB for the flooring. The sides of the attic, where there is no flooring, we have 18 inches of insulation. Would have liked to have installed 18 inches through out, but we needed headroom. I have checked the formula for attic ventilation, and I have sufficient ventilation. I have a ridge vent and soffit vents, baffles at the rafters. I installed all these myself, so I know they aren't blocked. I've noticed, once again, moisture in my attic. I pulled a small section of flooring only to find the insulation and flooring wet. The sides without flooring is dry. The moisture level in my house is between 40-55%. Our basement has always been on the damp side. Recently we installed french drains and sealed the walls. That helped bring our moisture level down to the current level. It has only been 4 months since we have done all of this. Contemplating eliminating storage area, but I really need this space. We heat with gas forced air and have a small ventless heater in the basement. We don't have bathfans, planning on installing when the weather breaks. Any ideas would be helpful. We are at our wits end.

 

Have you checked ALL things coming from the floor below, bathroom fans especially, but wiring holes, framing gaps, etc.??? Bath fans MUST exhaust to the outside. At 40%, that humidity level is ok(?) in winter, 55% is high. You say you have soffitt/ridge ventilation, but is it working(not inhibited by insulation), I suspect not. Old vents can clog with dust over time. How is the ceiling under finished(living side)???

 

When I had all insulation removed from the attic, I sealed every possible hole and crack I could find, electrical boxes, etc. Framing gaps...only the ones I could get from remodeling a few rooms. No bath fans at this time. 2 rooms are remodeled and finished drywall. The other 4 rooms and hallway are paneling and ceiling tile. The soffit/ridge vent is only 3 years old, and I was very careful installing the new insulation not to block the soffit, I used baffles. The small ventless gas heater in the basement is not lit constantly, but is used between 8-10 hours a day. Reading today that it causes extreme amounts of moisture. Can this cause this much moisture to make my whole attic this wet?

 

are you using that space just for storage ? then you could drill holes in the flooring to help it vent.
but then, depending on what you store, you could block those vents. unless you put spacers under the whatever.

 

It's the rh in the house. Lower the rh and this will go away. Sealing all the holes just spreds the issue over the hole attic rather than just a few areas.

 

Do you have gable vents? I was watching Ask This Old House and Tom Silva said if you have a ridge vent you never want gable vents. I know you say you are sure you don't have your soffit vents blocked but it never hurts to double check as something could have been pushed towards the vents. Also I advise against having insulation against the roof as it can cause a whole host of problems such as a weakened roof deck and prematurely failing shingles. We found that out ourselves when we had roofers over that we had called as my father had incorrectly installed the insulation and it was causing a great deal of problems. Instead of bats of insulation on the roof line I am convinced it is either better to leave that alone or hire professionals to come out and install closed cell foam insulation. Also I know this sounds crazy especially in winter but I think you need some fans running in that attic. Fans are about the only thing that will really help to remove a good deal of the moisture in the attic. As for your basement maybe getting rid of that ventless heater would be a good idea and replace them with electric baseboard heat permanently installed and then buying a good quality dehumidifier to help get rid of more moisture. Good luck to you!

 

I am having moisture in my basement area.. The place that is directly under my kitchen.... What should I do ?