Sealing an old chimney

[volks]

Hello! I've got an old fireplace in my house that the previous owners had a gas fire fitted into. The gas fire was a back boiler, so they had a metal chimney fitted inside the existing brick chimney, to allow venting of steam/vapours I believe.

The external chimney has a cap/cover fitted. See pictures.

The inside, I've put some loft insulation inside the metal chimney liner to avoid drafts (see pictured)

This has been fine for a year, but I've noticed some wind noise over the year. Tonight, with the heavy winds a load of old soot/brick fell down into the open fireplace.

I'm trying to work out how I can prevent this in the future (both avoiding falling dirt and drafts) without causing the chimney to become fully sealed and a source of damp.

Is it a simple job to put a board inside the chimney at room level to block the chimney, or is there a more involved process needed?

 

[Deluks]

You can just build a frame within the opening and plasterboard over it.
Put insulation behind the plasterboard, but a small vent might be wise to avoid condensation build up within the flue.

 

[Ivor Windybottom]

We've got the same issue. I have absolutely no intention of ever setting fire to stuff in my living room, and don't want the draughts.

I've stuffed an old pillow up ours. It bungs it up well without completely sealing it but, unlike loft insulation, is a single lump so won't fall apart.

The flashing on ours isn't very good, so I've decided that this year it's going. Going to get a roofer to take it down below roof level and tile over where it was. Then I'll remove the ducting, seal the bottom completely and fill the entire thing with loose-fill insulation. So it will still vent into the loft, won't get rained into and won't sing like a flute when the wind blows!

 

[elrick88]

I had similar problems plus the chimney was very old, had lead drip tray (or anything else) and it constantly leaked. Me and the missus got on the roof and took it down and tiled it over. Took around a day Plus if we decided we want a fire there again we can just build it up again.