I need to install some exhaust terminations in the roof for my bathrooms. I shouldn't have any problems actually installing the terminations (is that what they're called?) but what i'm wanting to know if there are any out there that don't slap around when the wind blows up against them.
When I did mine, I had to terminate thru the roof as well. I used 4" PVC for the run thru the attic and out thru the roof. The termination above the roof is a 90* and a 45* elbow so it points down. In the line inside the attic I installed an inline flapper similar to the ones found on the exaust fans. My local supplier has them in both 3" and 4".