"MarkL" wrote in message
ups.com...
On Jun 7, 12:29 pm, "ng_reader" wrote:
Trying to find a good diagram of this

http://www.gobrick.com/BIA/technotes/t19a.htm

Was about as good as I could, but does not explain my problem.

Recently getting my chimney swept, I was given an estimate of 1k to
replace
my disintegrated Smoke Shelf.

The guy was cool, said that is why I sometimes may get smoke in the room
(I
do --- but only initially and it goes away in less than 20 seconds), and
unless I was selling the house, no big deal.

But, on his estimate, he noted that the chimney could be brought "into"
code
with said Smoke Shelf.

Getting back to this Smoke Shelf, it is above the damper, and if it looks
like the diagram shown, how on Earth could it be disintegrated?

Color me curious...

Smoke shelves are a holdover from a time when people imagined it was
something that made sense. There have been tests showing there are
nowhere near as efficient as a straight hole up the chimney for
creating a proper draft. There was a good article in the Journal of
Light Home Construction a few years ago. So I wouldn't spend a dime on
it, unless it's to restore the ledge that is supporting the damper
assembly.


Well, the damper assembly does actuate a little funny. But it works, and he
made no mention of that. So, I will leave it alone, for now. I will google
that article, in case it is still on-line.