# Moisture coming from attic.



## Heathcote (Nov 20, 2013)

I recently purchased a 20 year old house in northwestern Ontario, the home has a garage and utility room on a ground level slab with the upstairs being the living area. I am in the middle of renovations and while pulling out old carpeting and cupboards I noticed some slight water damage and mold at the bottom of the second floor walls in 2 opposite corners of the house the moisture was coming down the walls between the drywall and the vapour barrier so I took down some drywall on the ceiling and noticed that there is almost no space for insulation at the corners of the roof because it is a very low pitch hip roof how can I insulate this area properly? Spray foam in the corners?






I went up into the attic and found a couple dark spots in the insulation where the roof trusses join on the main beam running across the house also there was no attempt to seal the vapour barrier to the beam or any of the wiring holes by the original builder so there all lots of air leaks that I can see and have had moisture around them.






None of the moisture has caused any severe damage or rot, from what I have been told the moisture has only been a problem in the last 2 years and the previous family had 9 people living in this home (don't ask lol) 7 children and 2 adults. They where the only ones that had any moisture problems I have spoken to other previous owners. These people said they had water dripping down the walls in the winter time. Now with that many people there will be huge amounts of humidity in the house with no dehumidifier or hvac system to get rid of it so with only 2 people living in the house it shouldn't be as much of a problem. What should I do to correct and deal with the problem? This is a pic of the main beam where the stack from the kitchen sink runs threw it there is some batt insulation stuffed around it to attempt to seal it.






Here is another pic of the main been not the black stuff on the insulation should I be concerned about this? Also notice the spots of the vapour barrier where water must have been sitting.






This is a pic of the underside of the batt insulation that was on top of the main beam.






Looking threw the attic access notice the evidence of moisture on the cardboard and the wood. There is 6" fibreglass insulation and about 7" of blow in.






What should I do to correct and deal with the problem?


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## SeniorSitizen (Sep 10, 2012)

In the 20 year life span of the structure it has experienced at least one ice dam problem and the number of sweaty, stinky human inhabitants has nothing to do with it.


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## joecaption (Nov 30, 2011)

There's not suppose to be insulation beyond the heated envelope.
Lack of air sealing, lack of Storm and Ice Shield under the shingles on the lower edges, blocked or lack of soffit vents.
Not enough, or improper roof venting.
No baffles to allow air flow to the roof vents.
Possible leak around a failed sewer vent roof seal.
http://www.bing.com/images/search?q...B209DF4868DF8EAFF62144BDC49EE&selectedIndex=8


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## Gary in WA (Mar 11, 2009)

Welcome to the forums! The plumbing vent pictures shows some very dirty fg batt from air/moisture coming from below, past the drywall somehow. The dirt spots on surface of fg is either roofing dust or dirty fg insulation again from a different air leak from below. Use some rigid foam board stacked up under the low clearance at the eaves, leaving 2" clear for air flow. Any mid-span roof vents (turtles, we call them) should be near the ridge, not in middle of roof as you won't get the warmer air out near the ridge. They should be spaced about every other bay apart, 1' down from ridge. 

Air seal any holes in the poly near the dark fg, (from catching dirt/moisture as it flows past- think furnace filter) and canned foam around the pipes/wiring holes because fg is a lousy air barrier; http://books.google.com/books?id=a298Hrpiu8AC&pg=PA123&lpg=PA123&dq=Proskiw+%281995%29&source=bl&ots=R3I2-fFVTl&sig=beKYTj24gopGv73x7cKL9XKEyJY&hl=en&ei=MHkNTbCWJou6sQPAiPXyCg&sa=X&oi=book_result&ct=result&resnum=1&ved=0CBMQ6AEwAA#v=onepage&q=Proskiw%20(1995)&f=false

http://www.wag-aic.org/1999/WAG_99_baker.pdf Air seal the attic, then air seal the basement/crawlspace to stop the stack effect. Number of occupants plays a semi-major roll towards additional humidity.

Gary
PS. we can figure your NFVA for your attic intake/exhaust vents if needed; http://www.airvent.com/homeowner/products/intakeSoffit-specs.shtml


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## Gary in WA (Mar 11, 2009)

Another thought; any bath fan, or dryer exhaust ducting terminate in the attic?

Gary


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