Wall thimble, to caulk or not to caulk?

[tiber]

Here's a question... I have the simpson duravent chimney and I'm happy burning. The other day in our lovely northeaster here I noticed there was a draft coming through the wall next to the class A where it goes through the wall thimble. It's not caulked, but it's more than a close enough fit that I didn't think it would be a problem. If I'm noticing a draft with my hand next to it, maybe it is a problem.

Do people caulk these or should I wrap it in aluminum tape? The manual makes no mention of either, the installation guide doesn't say to do one or the other so the manual seems to err on the side of "leave it alone". Thoughts?

 

[esuitt]

We caulked the thimble to the wall the pipe to the thimble for mine both inside and outside. One for air the other for rain/ water/ snow.

 

[begreen]

Silicone caulk the exterior entry of the thimble and then the storm collar.