Home  5  Books  5  GBEzine  5  News  5  HelpDesk  5  Register  5  GreenBuilding.co.uk
Not signed in (Sign In)

Categories



Green Building Bible, Fourth Edition
Green Building Bible, fourth edition (both books)
These two books are the perfect starting place to help you get to grips with one of the most vitally important aspects of our society - our homes and living environment.

PLEASE NOTE: A download link for Volume 1 will be sent to you by email and Volume 2 will be sent to you by post as a book.
Buy individually or both books together. Delivery is free!


powered by Surfing Waves




Vanilla 1.0.3 is a product of Lussumo. More Information: Documentation, Community Support.

Welcome to new Forum Visitors
 Join the forum now and benefit from discussions with thousands of other green building fans and discounts on Green Building Press publications: Apply now.




General: Extending stove liner to bring stove forward

Bottom of Page

1 to 18 of 18

  1.  
    • CommentAuthorKenny_M
    • CommentTimeFeb 12th 2022 edited
     
    Hi all,
    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
    • CommentAuthorJonti
    • CommentTimeFeb 12th 2022
     
    I would not want to make the fireplace smaller as it will lessen the efficiency but I do understand your desire to insulate. Can you not insulate behind the wall? I don't think there is any problem with covering the pipe.
    • CommentAuthorKenny_M
    • CommentTimeFeb 13th 2022
     
    Do you mean insulate on the outside? No, old house in a conservation area, so any insulation needs to be on the inside.
    • CommentAuthorCliff Pope
    • CommentTimeFeb 13th 2022
     
    Is that black lintel made of wood? There is surely supposed to be a clearance of 2" between an insulated double-skin flue pipe and anything combustible?

    Or is it even an insulated pipe, just a single skin convoluted pipe?
    • CommentAuthorKenny_M
    • CommentTimeFeb 13th 2022
     
    No wood anywhere in those pictures.

    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.
    • CommentAuthorowlman
    • CommentTimeFeb 13th 2022
     
    I 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.
    • CommentAuthorrevor
    • CommentTimeFeb 13th 2022
     
    I 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.
  8.  
    This 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

    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.
    • CommentAuthorphiledge
    • CommentTimeFeb 13th 2022
     
    If 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 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.
  10.  
    How 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.
    • CommentAuthorKenny_M
    • CommentTimeFeb 15th 2022
     
    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?
    • CommentAuthorKenny_M
    • CommentTimeFeb 15th 2022
     
    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.
    • CommentAuthorKenny_M
    • CommentTimeFeb 15th 2022
     
    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.
    • CommentAuthorCliff Pope
    • CommentTimeFeb 15th 2022
     
    With your two offsets the pipe upwards from the stove appears to be about 6" out from the wall.
    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?
  15.  
    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.
    • CommentAuthorfinny
    • CommentTimeMar 22nd 2022
     
    Hi Kenny,

    If you haven't already tackled this then I can draw you up the best solution for your scenario.
    • CommentAuthorJonti
    • CommentTimeMar 22nd 2022
     
    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.
    • CommentAuthorfinny
    • CommentTimeApr 19th 2022
     
    Hi Jonti,

    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:

1 to 18 of 18

  1.  
Add your comments

    Username Password
  • Format comments as
 
Back to Discussions Top of Page
   
The Ecobuilding Buzz
Site Map    |   Home    |   View Cart    |   Pressroom   |   Business   |   Links   
Logout    

© Green Building Press