[Sammy 2]

Just looked at a new home built this summer. The exterior was wrapped in Tar paper and Vinal siding installed over top. R20 in the walls with an interior 6 mil vapor barrier. The house should be air tight by design. The temp here is just below zero overnight and each morning the house exterior has a stripped appearance. You can see every wall stud and it looks terrible. The siding is a darker green color and a product of Royal Plastics. Any opinions on how to prevent this ? Thanks

 

[joecaption]

I personaly never would have used tar paper on the outside.
House wrap instead.
Now it sounds like you have a double vaper barrier which can trap moisture inside the walls.

 

[TheCamper]

If I understand you correctly, there is a frost on the exterior walls from overnight, in the morning there are "strips" where the studs are. The frost is melting where the studs are as the studs conduct the heat out from the house more readily than the wall cavity with the insulation. You often see this on roofs over a vaulted/cathedral ceiling. If I missed the mark here a photo would help.

 

[Sammy 2]

You are correct, the house looks like a Zebra until noon.:laughing: I am just wondering if the use of Tyvac or Typar would have been better. Perhaps the house should have been overlayed with styrofoam first ? Maybe some strapping as a spacer ? There must be a better way than to have a striped house every morning..........I am looking for a answer based on someone's experience Thanks.