I'm installing a wood stove. The regulations say that the chimney top should be at least 2 feet higher than any part of the roof within 10 feet horizontally . . . from what I've read, this seems to be all about draft. And it's also a bit unclear as to what the nearest part of the roof means. For instance, my house has a second story but the part of the roof that the chimney penetrates isn't a second story; in other words, the chimney goes through a first floor roof, but where it emerges, it's about 8 or 9 feet over to a second story external ( steel sided wall ).
So, if the chimney needs to go higher than that wall, it would be like 12 feet high, which seems unreasonable. But, if it's only about draft, I imagine the constraint is based upon the roof that the chimney comes from. So that it's not interrupting air flow.
Can anyone provide clarification?
Best Answer
It means what it says. If you go 10 feet from the chimney in any direction horizontally, you need to be at least 2 feet above the roof. Which means that your chimney is poorly located, if it's within 10 feet of a higher roof. So it needs to be 12 feet tall, if that's what it takes. Wind currents over that higher roof can cause downdrafts in the chimney - and that sort of thing is precisely what the language is there to prevent.
Depending how far along your install is, you could potentially move the chimney so it's more than 10 feet from the second story.