moisture/condensation issue

[EddieWalker]

Under the metal roof is 3/4 inch OSB. The inside/underside and under the eaves also is completely vented. On top of the OSB is a snow guard type sticky membrane.

There are only two natural sources of water getting between house wrap and sheathing on a wall. Condensation or rain. If it hasn't rained in a long time, and you are 100% positive that the water isn't from rain, and you didn't notice it right after it rained, then the only other source is condensation.

Either way, it's coming from your roof. Water goes downhill, but it also follows a path of least resistance, and sometimes, that means it goes sideways, and it goes underneath eaves.

How positive are you that your screws on your metal roof where not overtightened? I've had jobs where the rubber seals where cracked and/or squished enough to allow water through the roof. The water hit the tar paper under the roof and followed it down the roof, under the metal, until it came out the eaves. For days after it rained, water would continue to slowly leak out under the metal roof, down the side of the house.

Have you been up on a ladder, at first light, when condensation is forming everywhere else, and looked real close at what's happening where the wall and roof come together? Somewhere there is a path for water to get behind the house wrap, and that is going to be at the top of the wall, where the house wrap starts.

 

[yanmars]

I used the 3/4 as I had plenty on hand I wanted to use up. Stored inside for years but got rained on once before the house wrap went on.
My metal roof is a type of standing seam, there are no visible screws or gaskets. The only thing new is leaf guards on the spouts and snow guards to keep snow from sliding off the roof.