We have been living in our new building for a little over six months. Today, when I was about to go to the attic, a wasp looked at me. I was a little shocked, the wasp probably was too. But now I'm wondering if the roof is airtight. Or is it okay to have holes through which wasps can fly in? It's a cold roof, built in such a way that you can see the wooden beams under the roof.
The ridge should be open or have mesh for ventilation. Wasps can get in there no problem. It's not a building defect, it's just a cold roof.
Joints in masonry are also popular.