# Metal roof with Fan board insulation, Still have condensation trouble



## rollenrock33 (Jan 27, 2010)

Hi,

Not sure if this is the place to ask this, but I am having trouble with a new roof on the house I am building. The roof is metal with green guard fan board insulation under it. Seems were not taped even though I thought they should of been. The trusses are cathedral (scissor type truss). I am getting a little bit of water coming down onto the soffit and it is then freezing onto the wood soffit that took me so long to make. Is there any way to fix this??? Thanks for your time.

Matt 

Somerset, Pennsylvania


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## Tom Struble (Dec 29, 2008)

what are you attributing the water from?condensation? roof leak?

is it a concealed fastener roof or is it screwed down thru the face of the pan?

need more info and some pics far enough away to see the roof and overhang


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## rollenrock33 (Jan 27, 2010)

well at first I thought it was condensation but now I think I have it narrowed down to ice building up in the valleys and creeping up the rips of the sheeting. The valley flashing extends about a foot under the sheeting. Any ideas on how to stop this from happening? Thanks.


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## Tom Struble (Dec 29, 2008)

did you use any underlayment in the valley before you put the metal valley down?

no i don't know,sounds to me like the roofing has to be removed in that section to see whats going on
i never heard of using fanfold insulation under a metal roof

did you install it or did you hire it out?


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## rollenrock33 (Jan 27, 2010)

I used a local contractor. He said that he never heard of this happening before. Nothing other that the fan board was put down. The roof has perlins, not sheeted in with osb, so not sure what you would put under the valley flashing. Would a roll of Ice and water shield work even though it would be on perlins?


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## Tom Struble (Dec 29, 2008)

hhmmm yea some guys are using outbuilding type metal roofing details for houses now,I'm not sure that's very smart.Alittle condensation or minor roof leak is usually not much issue in an unheated barn,but in a house its unacceptable


no i&w will not work on purlins,very easy for moisture to condense on the underside,what kind of insulation in the attic?I can see what he was trying to do with the fan fold but I'm not sure how effective a 1/2'' perforated foam is going to be


without seeing the details of the valley and such its impossible to give much guidance

get the roofer back and tell him to fix it whether he has heard of it or not


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