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Discussion Starter #1
I'm not sure what's going on here... The plywood in the attic is all wet and black (mold?) on the north side of the ridge. The other side of the ridge is fine. I was thinking the problem could be humidity from the bathroom vent but then I checked the vent and couldn't notice any rust or damage. Also, if it were humidity wouldn't it be throughout the attic and not isolated??
 

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I would like to see whats under the yellow insulation wrapped around the exhaust pipe,looks iffy.That could be the root of the problem.Could also be lack of attic ventilation.That would be what I'd look into first.Find out the root of the problem and then call a professional to take care of the mold.
 

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Ed the Roofer or The Roofing God may know something I don't on your situation.(I doubt it though,J/K guys)They should chime in on this at some point.
 

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North sides are typical to have more frost, which in turn can permeate the decking if the ventilation is not up to specs.

By that, I mean Balanced Ventilation, creating a continuous current of Intake from the bottom through and out of the Exhaust Ventilation.

Also, being so isolated, I would first look more stringently for leakage from the fan ducting kit and how it is connected to the damper bent on the exterior of the roof.

If it is connected to a standard mushroom style turtle static air vent, then there is definite air leakage at that connection.

What is the ventilation calculations and the horizontal footprint square footages?

Ed
 

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If it is most concentrated around that vent and gradually feathers out from it, then that is the likely culprit. If it's a humidity issue it generally will be a more even disbursement under the decking in some areas.
 

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Curmudgeon
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Though if it's a drywall ceiling,
most people really don't run the
fan enough.
Bet it'd mostly poor attic ventilation.
 

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I don't see an intake, but maybe that's just a bad pic without a flash. All that plywood has to be stripped off and replaced, and probably the insulation too since it is infested with mold. What type of exhaust ventilation is present? How much insulation? Are there any bath or kitchen fans that vent directly into the attic? I see there is a duct for a fan right there, is it properly connected?

Try replacing that insulated rigid duct with an insulated flexible duct, with as little slack as possible. I have better results getting a good connection, also with no joints. One seamless shot from fan to vent.
 

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Damn I'm glad the climate here is dry as...the only thing bad ventilation does here is fry the shingles. But that would seem to be the issue there, altho,

Details man! Details man!

Ventilation = the mystery trade.
 

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Discussion Starter #9
Thanks for all the replies and info! I've attached a couple more pictures to show what's going on. The upstairs attic is 850 sq ft. There are 4 static vents (9x9 inches each one) , 2 gable triangular vents (21" long by 7" high) and 1 gooseneck (static) where the bathroom vents out to.

I checked the soffits from below because when I was up in the attic it's totally black - had to prop up a powerful flashlight just to take a look around. I tried to get at the soffit area but can't see beyond the batts at the other end - I was assuming that the batts should be stopping the blown in from getting over the soffits?

There's one soffit vent (see picture) and the rest of the air is supposedly coming up through the perforations.

I think one of the problems has to be the bathroom vent - what's the best way to do that when the plywood's wet? Should I reccomend that they get new insulation?
 

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Thom
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One soffit vent? It's ventilated soffit. If all the soffit looks like that there's plenty of soffit venting. Of course it doesn't do any good if the ventilation can't get into the attic.

No only does there need to be space above the insul at the eaves for air passage, you should check to insure that the insul was not blown into the soffit as well.

Then, get some gable end vents, or put some mushroom vents just below the ridge.

Solve the airflow problems and insure it will dry out properly before putting on the new deck. No sense trashing a second one.
 

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Well, the roofdeck IS shot but at least you can solve the sources of your issues. Repair that fart fan ducting and ensure it is not leaking and it is properly venting out the roof. More importantly, it looks like the insulation is blown right over the soffits thus making it useless. Clear all the soffits and make sure you can see plenty of light coming in from it. Might think about sealing up the gable vents while you are at it. Based on the attic space, 4 9" cans should be more than adequate exhaust as long as the soffits are clear. The gable vents are just negating the efficiency of the system.
 

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Replace the bad plywood, convince the guy it HAS to be done before it spreads & he starts breathing the crap in. Save a roof.... save a life.:thumbsup:
 

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Handle It!
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malco - what do you mean? what about dry ice? (minus the beer)
Bleach and water is useless on wood.

You need a mold killer that is registered for use on porous/semi-porous surface. Then treated the cleaned area with a mold blocker, which will provide a few years of protection against further mold growth.
Replace the bad plywood, convince the guy it HAS to be done before it spreads & he starts breathing the crap in. Save a roof.... save a life.:thumbsup:


That is what I mean!!!!!
 

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Definitely a multifaceted issue: Likely leaky exhaust duct work. No airspace at the eaves between the roof decking and the insulation. And that round "soffit vent" you refer to is likely an additional exhaust vent from somewhere - investigate that. If that duct work has separated or is leaking in the soffit area that contributes to your problem.

As far as the delaminated (moldy?) plywood is concerned, go for a walk on the roof, you'll probably step through and then it will became an insurance repair issue. Win win :thumbup:
 

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You need at least one of those vents every rafter bay. Plus you're going to have to pull the isnulation from blocking the intake.

She can't afford to fix this right? Can she afford all the health problems she's going to get if she stays living there? I'm willing to bet that degree of mold is real bad news for her lungs. She needs what she needs man, and she needs to get rid of that mold which means replacing alot of area of roofing. She also needs to sue who ever did her soffits for not cutting the openings beneath the vented panels.
 
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