How big can a top cap be?

Just curious what our thoughts are on this house’s chimney top cap. I haven’t been up to measure it, but from the ground - it appears easily 5 feet or better diameter. Also, it seems awfully close to the clay flue liner. Is there any limitation for effective draft or diminished draft causation here because of the massive size, or is ok?


Wow, that is a first. I do not have your definitive answer at the moment, but I believe 5" is the industry standard between the tallest flue and the cap. The overall diameter of the cap is crazy.

But, did you see evidence of a drafting issue at any of the components which use this chimney?

No it SURPRISINGLY looks fine throughout, but the heavy sooting stain underneath it is concerning to me. It just looks so absurdly wrong to the first glance. Also missing bird / critter cage or spark arrester from the looks of it.

Yeah, never seen anything that big before either. Is that some sort of flashing being held in place by bricks around the chimney?

That cap looks like the flying nun head gear and about to fly away. LOL


Had one custom made for the last house…4 chimney flues together center roof. Stainless steel about 4 ft. across. called it the helicopter pad , but it worked.

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