But I don't think have seen this version..

My 1920s house has three brick chimneys. All on outside walls, all 'stick out' (so inside walls are flat) if you see what I mean.

Chimney 1: Unused. Taken down to loft floor level (under eaves). Two flues, one bricked up with vent to bedroom, one with no vent bricked up in dining room.

Chimney 2: Stack remains. One flue used, in lounge. One flue unused, bricked up with vent in bedroom.

Chimney 3: Unused. Taken down to loft floor level, as above. Masonary is half height, only to first floor. One flue, bricked up with vent in bedroom.

Complete removal would be expensive, and I am aware there would be cold bridging if they remain. iwi is not really an option. So given those restrictions, what would be best way to reduce heat loss (and prevent damp)?

Thanks.

<blockquote><cite>Posted By: Peter_in_Hungary</cite>EWI would solve the problem. Otherwise fill chimneys 1 and 3 with EPS beads and chimney 2 fill unused flue with vermiculite because that would be better if anything nasty (= fire) happens to the in use flue. Vermiculite is not as good as EPS regarding damp but IMO not an issue with an adjacent in use flue

Do you have solid or cavity walls?</blockquote>

Sorry, 50mm cavity walls. No IWI as yet.

EWI on the chimney would not be possible due to space, either. I suspected EPS beads would be suggested - it seems to be the default solution atm. So block off air vents, fill with beads (except number 2), maybe as part of IWI installation, and done? I guess it would be just like normal wall cavity.

Will look into vermiculite installation.

Thanks very much..

LECA is also good, I have used it twice to backfill around flexi flue liners

<blockquote><cite>Posted By: Jonti</cite>Osprey,

maybe I have misunderstood but you say in your first post IWI is not an option and that EWI is also not possible in your post #2</blockquote>

To be clear, I cannot add insulation to the exterior surface of the cavity wall, nor the interior surface. I can insulate the cavity itself. (Sorry for misuse of the TLA)

You definitely want the chimneys capped but ventilated. If theres access from within the loft you can make an opening there and have a vented pot/cap.

As therell be a cold bridge from the rooms below to the loft you can lengthen the bridge by filling the chimney a couple feet above the level of the loft insulation and then clad the accessible exterior of the chimney in insulation level with the beads inside the flue.

No access within the loft to clad accessible bits??

Yes

If access is limited, layer up the loft insulation as high as you can get it against the chimney and fill the flue a little above wherever you can get the insulation to within the loft.

Double all the wood work is dry where the roof joins the chimney and check the flashing when you fill with beads.

Hi,

Apologies for jumping in on this thread, I have a similar situation as Chimney 3 - chimney taken down in to the loft, blocked up in the house but with no vent. Would be useful to get your thoughts on my situation.

I have bought EPS beads to fill in the chimney.

From reading elsewhere I understood that I need to insert an air brick in the chimney in the loft above loft insulation to allow air flow.

I have taken out a brick from the chimney, I then 'hit' the flue liner. The house in 1950s built and I have been on a real learning curve with asbestos that I then stopped and researched, and yes, asbestos may well be in flue liners.

So...I have ground to a halt. I don't want to drill through the flue liner. Can I safely fill the flue with EPS beads without the air brick?

Any comments welcome.

Ashley

There are sellers on eBay - e.g. 2400 litres for £215 - but I can only see white beads, without adhesive, which MAY be OK for e.g. underfloor use.

If you wanted a decent quantity, maybe give one of the bead manufacturers a call, such as Evobead.co.uk?

There is an earlier poster (a few years ago I think) that said he got his beads cheap from a company that removes CWI. Hopefully, that is not done so much nowadays, but maybe worth a call to a couple!