Green Building Forum - Extending stove liner to bring stove forward Wed, 10 Jun 2026 07:49:32 +0100 https://www.greenbuildingforum.co.uk/newforum/ Lussumo Vanilla 1.0.3 Extending stove liner to bring stove forward https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=17388&Focus=294729#Comment_294729 https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=17388&Focus=294729#Comment_294729 Sat, 12 Feb 2022 16:57:09 +0000 Kenny_M As pictured, I have a small 5kw stove, within a large exposed stone fireplace. The back wall will be fairly thin single skin stone.

I would like to insulate and reduce the size of the fireplace using rockwool and cement board, but if I did this a section of the black vitreous pipe would be buried behind the cement board/insulation.

Does anyone know if there is any issue with this?

I think I read somewhere that the black pipe needs to be exposed, but not sure why.

Edit: I had some problems attaching photo so have had to go with the links below:

https://www.dropbox.com/s/72njdowh62l8czt/2022-02-12%2016.02.46.jpg?dl=0

https://www.dropbox.com/s/pr9rstkyts8wrao/2022-02-12%2016.03.21.jpg?dl=0

Thanks
Kenny]]> Extending stove liner to bring stove forward https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=17388&Focus=294735#Comment_294735 https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=17388&Focus=294735#Comment_294735 Sat, 12 Feb 2022 20:55:56 +0000 Jonti Extending stove liner to bring stove forward https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=17388&Focus=294736#Comment_294736 https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=17388&Focus=294736#Comment_294736 Sun, 13 Feb 2022 07:48:48 +0000 Kenny_M Extending stove liner to bring stove forward https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=17388&Focus=294738#Comment_294738 https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=17388&Focus=294738#Comment_294738 Sun, 13 Feb 2022 09:47:35 +0000 Cliff Pope
Or is it even an insulated pipe, just a single skin convoluted pipe?]]> Extending stove liner to bring stove forward https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=17388&Focus=294740#Comment_294740 https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=17388&Focus=294740#Comment_294740 Sun, 13 Feb 2022 11:08:40 +0000 Kenny_M
I think what you might be seeing is the blackened inside edge of the original sandstone lintel, blackened from when it was a fireplace long ago. All manufacturers distances to combustibles have been adhered to.]]> Extending stove liner to bring stove forward https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=17388&Focus=294743#Comment_294743 https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=17388&Focus=294743#Comment_294743 Sun, 13 Feb 2022 13:53:56 +0000 owlman Can you not first Drop a small "ceiling" in the fireplace to cover the stovepipe/ flue liner junction, and then insulate and line the walls. If you are worried about the proximity of the liner to the new "ceiling" material you could leave a small gap and cover it with a SS collar.]]> Extending stove liner to bring stove forward https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=17388&Focus=294744#Comment_294744 https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=17388&Focus=294744#Comment_294744 Sun, 13 Feb 2022 15:11:36 +0000 revor Extending stove liner to bring stove forward https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=17388&Focus=294745#Comment_294745 https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=17388&Focus=294745#Comment_294745 Sun, 13 Feb 2022 15:27:20 +0000 WillInAberdeen https://www.stovefitterswarehouse.co.uk/pages/stove-fitters-manual

We had a fireplace with an exposed stone single-thickness back wall which was drafty from micro cracks in the pointing. Fixing these gave a good improvement, worth doing before covering over.]]> Extending stove liner to bring stove forward https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=17388&Focus=294746#Comment_294746 https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=17388&Focus=294746#Comment_294746 Sun, 13 Feb 2022 15:51:38 +0000 philedge
I couldnt see a register plate and if there isnt one fitted it might be a good idea to fit one and fill the chimney with vermiculite to insulate the flue/chimney.]]> Extending stove liner to bring stove forward https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=17388&Focus=294750#Comment_294750 https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=17388&Focus=294750#Comment_294750 Sun, 13 Feb 2022 18:17:57 +0000 renewablejohn Extending stove liner to bring stove forward https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=17388&Focus=294774#Comment_294774 https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=17388&Focus=294774#Comment_294774 Tue, 15 Feb 2022 09:16:51 +0000 Kenny_M Posted By: renewablejohnHow on earth do you intend sweeping that chimney. Would love to see the Hetas certificate of whoever installed that. Does your stove not have a rear exit option as an insulated pipe would be an easier option straight up the wall.

Thanks. It does not require a HETAS certificate as it is in Scotland, but the installation does fully comply with building regulations.

The stove has been recently swept by a certified chimney sweep, a pretty experienced guy actually, and he didn't raise any concern about the setup, or the ability to sweep. There is a plate inside the stove that is removed to sweep.

You seem to be quite critical with the comment about the HETAS certificate, but what is it that you actually think is specifically wrong with the installation?]]> Extending stove liner to bring stove forward https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=17388&Focus=294775#Comment_294775 https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=17388&Focus=294775#Comment_294775 Tue, 15 Feb 2022 09:22:20 +0000 Kenny_M Posted By: owlmanI agree broadly with what Jonti said.
Can you not first Drop a small "ceiling" in the fireplace to cover the stovepipe/ flue liner junction, and then insulate and line the walls. If you are worried about the proximity of the liner to the new "ceiling" material you could leave a small gap and cover it with a SS collar.

I'm not worried about the proximity of the new materials to the stove pipe. The only materials I would be using are non combustible. My question about the stove pipe was because I had read somewhere, on a forum I think, that the black stove pipe should not be buried. I think the suggestion was that it could rot, but I don't understand why that would be the case any more than than stainless liner, so I was trying to find out if there was any truth in that.


Posted By: revorI cannot quite make out the junction of the stove pipe into the liner. It could be picture is dark at that point. There should be a proprietary junction piece between the two to avoid leak back into the room if there is a blockage or restriction in the flue. It is also designed to allow any rain water or condensation to drain into the stove otherwise it can leak to the outside of the stove pipe and cause staining of decor etc.. What Jonti suggests would be a good move. As you will be moving the stove forward to do the job you will be refitting the stove pipe with new parts so you could attend to the junction I have mentioned at that time.


The junction from the liner is via a step down, as the liner was much wider (around 10" I think), than the stove pipe which was fitted later and needs a 5" exhaust. The joints are all sealed with pipe cement.

Not sure I am following what you are saying about the issue with the junction, or if you just can't see it properly in the picture. The parts used are all designed for stoves, and its all sealed. Any rainwater running down the liner would run down through the stepdown and then the vitreous pipe and into the stove.]]> Extending stove liner to bring stove forward https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=17388&Focus=294776#Comment_294776 https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=17388&Focus=294776#Comment_294776 Tue, 15 Feb 2022 09:32:21 +0000 Kenny_M Posted By: WillInAberdeenThis chap publishes an online manual, he might reply to an email if you can't find the exact info needed?
https://www.stovefitterswarehouse.co.uk/pages/stove-fitters-manual" rel="nofollow" >https://www.stovefitterswarehouse.co.uk/pages/stove-fitters-manual

We had a fireplace with an exposed stone single-thickness back wall which was drafty from micro cracks in the pointing. Fixing these gave a good improvement, worth doing before covering over.

Thanks - An email to the stove fitters warehouse is probably a good idea thanks. I used that site before, and bought the stove from them, but I didn't find them overly helpful by email when I contacted them before, but worth a try.


Posted By: philedgeIf you rotate the adapter in the of the flexy liner 90 degrees it will move the enamelled section forward a few inches giving more room for insulation on the wall without covering the enamelled pipe. Make sure you use non combustable high temp insulation behind the cement board.

I couldn't see a register plate and if there isn't one fitted it might be a good idea to fit one and fill the chimney with vermiculite to insulate the flue/chimney.


Thanks - Insulation will either be rockwool or a combination of this and vermiculite, which are both A1 rated.

I think the angle of the pic might be misleading, rotating the junction won't bring anything forward. I've tried manipulating the stove forward, to make space at the back, but it just puts too much pressure on the junctions and pulls them into angles that make for a poor seal. If I move it forward I would probably need to change some of the parts.

When the liner was fitted it was filled around by pouring from the top with vermiculite cement, so its solid all around the liner and no real need for a register plate.]]> Extending stove liner to bring stove forward https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=17388&Focus=294785#Comment_294785 https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=17388&Focus=294785#Comment_294785 Tue, 15 Feb 2022 11:44:00 +0000 Cliff Pope I'd have thought that was easily enough for insulation on the back wall?

The double offsets creating a two-stage join looks a bit untidy - can't you achieve the necessary bends in a single offset? I just thought a re-design here might also allow an access plate and a flue damper - or is one hidden in the picture?]]> Extending stove liner to bring stove forward https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=17388&Focus=294787#Comment_294787 https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=17388&Focus=294787#Comment_294787 Tue, 15 Feb 2022 11:57:35 +0000 renewablejohn Posted By: Kenny_M
Posted By: renewablejohnHow on earth do you intend sweeping that chimney. Would love to see the Hetas certificate of whoever installed that. Does your stove not have a rear exit option as an insulated pipe would be an easier option straight up the wall.


Thanks. It does not require a HETAS certificate as it is in Scotland, but the installation does fully comply with building regulations.

The stove has been recently swept by a certified chimney sweep, a pretty experienced guy actually, and he didn't raise any concern about the setup, or the ability to sweep. There is a plate inside the stove that is removed to sweep.

You seem to be quite critical with the comment about the HETAS certificate, but what is it that you actually think is specifically wrong with the installation?
If your happy then thats fine but to me its looks very Heath Robinson. I am not convinced you could get a chimney sweep rod up though that S bend. I know sweeps just tickle a chimney now with a vacuum cleaner but if you had a serious soot fall and blockage at that S bend I would want to get at it to clear it. On that basis I would have expected the first bend from the stove straight section to have incorporated a rod access point which would have eradicated the problem of the S bend.]]> Extending stove liner to bring stove forward https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=17388&Focus=295434#Comment_295434 https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=17388&Focus=295434#Comment_295434 Tue, 22 Mar 2022 07:28:21 +0000 finny
If you haven't already tackled this then I can draw you up the best solution for your scenario.]]> Extending stove liner to bring stove forward https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=17388&Focus=295435#Comment_295435 https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=17388&Focus=295435#Comment_295435 Tue, 22 Mar 2022 07:51:15 +0000 Jonti Posted By: finnyHi Kenny,

If you haven't already tackled this then I can draw you up the best solution for your scenario.

Hi Finny,

even if Kenny has already tackled this it would be interesting to see your suggestion.]]> Extending stove liner to bring stove forward https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=17388&Focus=295888#Comment_295888 https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=17388&Focus=295888#Comment_295888 Tue, 19 Apr 2022 15:34:13 +0100 finny
Photo seems to be deleted..

I think from memory something like this tho..Put a galv closure plate in, drop a 5 inch, if the stove is DEFRA, or a 6 inch liner through whats there, terminating in a top hat adapter fixed to the galv plate, all as far forward as practicable. Skamolex board over simple parging lime mix to fill the gaps and even the wall out a bit. 25 or 30 mm of that goes a long way to prevent heat lost to that wall, but if there is room I would add a metal heatshield stood off the skamolex by 25mm open top and bottom to grab any heat that goes that way and convect it back into the room.

Connecting fluepipe would then be either that fixed offset thats in there now which looks like giving 100mm offset if its like the ones we use, or if thats not enough and the hearth can be configured nicely to give the required distance in front, you could T into the back of the stove and get more room for the insulation/convector shield.

If anyone is genuinely stuck on flue design or needs a second opinion I am happy to help.. for beer if its a quick simple one

:wink:]]>