Sat, 13 Jun 2026 21:18:33 +0100 https://www.greenbuildingforum.co.uk/newforum/ Lussumo Vanilla 1.0.3 https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=12110&Focus=202267#Comment_202267 https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=12110&Focus=202267#Comment_202267 Tue, 20 May 2014 11:25:37 +0100 Victorianeco
I intend to use the living room fireplace only with a 316 liner.

What should I do with teh other three unused chimneys?

In work (Council Housing) we generally block them up and just put an air vent in the wall.

What is best practice? Aim is to keep chimney clear of damp but also want to reduce any heat loss?]]> https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=12110&Focus=202279#Comment_202279 https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=12110&Focus=202279#Comment_202279 Tue, 20 May 2014 15:22:31 +0100 tony https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=12110&Focus=202280#Comment_202280 https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=12110&Focus=202280#Comment_202280 Tue, 20 May 2014 15:32:29 +0100 jfb
also - is vermiculite better than say EPS balls?]]> https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=12110&Focus=202283#Comment_202283 https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=12110&Focus=202283#Comment_202283 Tue, 20 May 2014 16:02:47 +0100 tony https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=12110&Focus=202284#Comment_202284 https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=12110&Focus=202284#Comment_202284 Tue, 20 May 2014 16:46:42 +0100 richardelliot
Does anyone have any suggestions for treatment of the chimeny in this case?

Thanks.]]> https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=12110&Focus=202285#Comment_202285 https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=12110&Focus=202285#Comment_202285 Tue, 20 May 2014 17:10:39 +0100 jfb
well - I have seen conflicting things on this forum about that but some companies I have spoken to don't say it is impossible. Need adequate sizing and insulation.
Similar situation here with 3 unused pots right by where the MVHR unit could go near the apex of roof.]]> https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=12110&Focus=202309#Comment_202309 https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=12110&Focus=202309#Comment_202309 Tue, 20 May 2014 21:50:37 +0100 Victorianeco https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=12110&Focus=202318#Comment_202318 https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=12110&Focus=202318#Comment_202318 Tue, 20 May 2014 23:45:21 +0100 tony https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=12110&Focus=202329#Comment_202329 https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=12110&Focus=202329#Comment_202329 Wed, 21 May 2014 09:37:56 +0100 jfb
is it because vermiculite is better at buffering moisture?]]> https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=12110&Focus=202340#Comment_202340 https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=12110&Focus=202340#Comment_202340 Wed, 21 May 2014 14:45:52 +0100 Victorianeco https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=12110&Focus=202348#Comment_202348 https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=12110&Focus=202348#Comment_202348 Wed, 21 May 2014 17:16:28 +0100 tony
In an closed off chimney the top gets very cold, condensation occurs and the cold air falls down the chimney, warm moist air rises, this dries the chimney breasts and indeed the house but dumps water in the form of condensation in the top of the chimney, saturating it until it can take no more at which point it starts dripping, running down the flue. This is like a cold tropical rain forest and not good.

Block the flue at ceiling level, insulate over it -- ventilate the top part of the chimney and add ventilator cap and/or air brick.

Vermiculite helps reduce thermal bypass, is easy to remove and keeps it all happy. It is not involved in the pumping.]]> https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=12110&Focus=202364#Comment_202364 https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=12110&Focus=202364#Comment_202364 Wed, 21 May 2014 20:12:44 +0100 jfb
so if I have a warm pitched roof and am trying to get a good level of airtightness and install MVHR I can get away without putting an air brick above where I close the chimney off if I have a ventilator cap (assuming I insulate)? I am having vaulted ceilings all the way to roof level.

If not how else can I ventilate the chimney without putting more holes in it?!]]> https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=12110&Focus=203021#Comment_203021 https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=12110&Focus=203021#Comment_203021 Mon, 02 Jun 2014 19:20:09 +0100 Victorianeco
Is there really anypoint therefore in bothering with insulation fullstop?

I could just put a small vent at the base of each fireplace (minimum size??) to ensure ventilation]]> https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=12110&Focus=203026#Comment_203026 https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=12110&Focus=203026#Comment_203026 Mon, 02 Jun 2014 19:53:56 +0100 barney
If you ever get the chance on a cold, still day, stand by a flue pot and you can easily feel the warm air rising from it - it's quite considerable.

I'd insulate and cap it at the highest point the heated envelope rises to, fill the flue with EPS beads, vermiculite, LECA or similar and stick a rain cowl on the pot.

Unless you keep the fire place open, the insulation sits on the fire slab. If you keep the fireplace open then a reasonable register plate keeps it all "up there"

All assuming it's not end of terrace and exposed to the outer wall of course

Regards

Barney]]> https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=12110&Focus=203027#Comment_203027 https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=12110&Focus=203027#Comment_203027 Mon, 02 Jun 2014 20:14:00 +0100 Victorianeco https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=12110&Focus=203028#Comment_203028 https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=12110&Focus=203028#Comment_203028 Mon, 02 Jun 2014 20:18:17 +0100 Victorianeco
I mean how much would it cost to line 4 disused chimneys with vermiculite or similar?]]> https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=12110&Focus=203030#Comment_203030 https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=12110&Focus=203030#Comment_203030 Mon, 02 Jun 2014 20:24:35 +0100 Victorianeco https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=12110&Focus=203031#Comment_203031 https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=12110&Focus=203031#Comment_203031 Mon, 02 Jun 2014 20:38:52 +0100 barney
Measure the flue - I think you'll be suprised by how little volume it actually has when it comes to filling it

Regards

Barney]]> https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=12110&Focus=203043#Comment_203043 https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=12110&Focus=203043#Comment_203043 Mon, 02 Jun 2014 22:46:35 +0100 Victorianeco