Thread: Anyone know what this is?

It doesnt appear to be connected into the main fireplace anywhere, no holes, except that big one in the middle.

Not to any crawlspace I'm guessing or you would have crawled down into it right?

Marc,

Where were you standing, in the attic looking down? In a basement looking down?

If I am looking at the picture right and you are looking down from the fire box then it is a ash pit they used them in coal fireplaces there are normally a clean out on the floor below I have a house that has 2 of these one on second with a cleanout on the main floor and the one on the main level has the clean out in the basement

Oops, I should have said where I was, sorry. I was in the attic looking down at the fireplace where the it comes thru the ceiling.

You may be looking at a "dummy" flue built to create some sort of aesthetic effect below the ceiling line in the structure's interior. It's not properly lined as would be a functional flue.

In terms of thermal performance, this "hole" may be an enormorous energy leak if all that separates the conditioned space of the structure from the attice is a single wythe of brick. If that's the case, suggest plugging this "hole" with insulation.

Yea, interresting... I thought it was an after thought or mistake.

You guys are so informative. I was going to say it was a hole in the floor.

Marc,
It may also serve as a fresh-air intake into the FP??? Did you see an openings/vents on the insides of the firebox? Is that insulation that is down inside the opening? Hopefully not.