Moisture between vapor barrier and insulation in shed

[Victag]

We have just insulated our shed and put vapor barrier inside the insulation, with a layer of tar paper between the insulation and the siding. We are noticing that one wall is sweating and moisture is collecting between the insulation and vapor barrier. Berfore we drywall, we want to eliminate the moisture. The attic of the shed is vented, so I can not understand why we are seeing this moisture still? Does anyone have any advice as to how to fix this and why we would still be getting moisture? We would like to use the shed as an office and have also installed heating. Are we still lacking proper venting or is this likely because we have not properly sealed the vapor barrier? Thanks in advance for any help.

[Victag]

If it makes a difference, we are in BC Canada, moist climate with a mix of cold and warm.

[Michael Bulatovich]

If for some reason the air outside is warmer/wetter than it is inside, you could get condensation on the 'outside' of the VB. Another possibility is a water leak into the wall, from above, or from wind driven moisture through joints.

[Victag]

Thanks for the reply Michael, We have had the heat on high so it is definitely warmer inside and the moisture is a sweat on the whole wall, so we have ruled out any leaks. We have just replaced all VB and insulation trying to solve this problem and it is back again. Thank god we did not put up the drywall yet!

[Michael Bulatovich]

How's the weather been lately? Raining? Any wind-driven rains? What about surface drainage? Is it sloped away? Something is putting water in your wall.

[Rima Neas]

I am here asking questions myself, so do not presume to know the answer, but....

If the insulation was previously made wet, it would stand to reason that you would get renewed moisture on the VB after re-sealing the cavity. Under this scenario, you would have even more condensation on the felt paper under your siding. Another, albeit unlikely, source of moisture is the lumber used to make your wall. Perhaps if it was quite green and got a good soaking prior to being sealed in. If you were to open things up yet again, make sure to let everything get bone-dry before putting up a vapor barrier.

Cheers, Shawn

[Bill]

Is the wall in question facing east?

[Michael Bulatovich]

I just noticed this line. There is nothing but paper between the studs and the siding?