Mamba wrote:

We had a similar situation in a 1908 home. After trying both glass doors
and a top-mounted flue to augment the firebox flue, we decided to make a
compression-fit block for the flue and essentially decommission the
fireplace.

I took a lighweight block of styrofoam and wrapped it with bubblewrap to
about 2" wider than the dimensions of the flue. I added a rope-loop handle
to the "bottom" of the plug to allow for removal, and crammed it into
position about 12" above the firebox, where the flue starts to narrow.
Naturally you would never, ever have this in place if you expected to burn.
We did however have a couple of small candles in the firebox that we lit
occassionally for ambience ;-)

Can't speak to the leaks around the unit, as I am only familiar with
brickwork fireplaces - is this an insert?



I "decomissioned" one too. Wife did not like smoke and fireplace was out
of code because of 90 degree bend. Already had glass door but these can
leak too. I had chimney capped. Could have done it myself but my roof
climbing days are over. I siliconed the damper shut and after cleaning
fireplace we added a low cost electric insert which looks great and can
give off a little heat.

Fireplace guy had recommended siliconing in a cut metal plate to block
flue but damper handle was in the way.

Frank