Hi,
In the process of sorting out a fairly shabby conversion of an 1843 Church. The plan was to remove a corner fireplace in the kitchen and install a free standing wood burning stove. The outline plan was to break into the chimney flue 2/3 of the way up the wall and connect to flexi liner to the top. We are at the prep stage, trying to make it installable before we get a HETAS guy to do the actual installation.
Anyway, this is what we've found having removed a cast iron fireplace front that had a wholly unusable "homebrew" and flammable decorative wooden surround.
The masonry flue is right in the corner, behind those double 4x2 studs.
As you can see, the walls are internally insulated - studs, celotex, 9mm osb, then plasterboard thus Twin Wall flue would need to be used to enter the masonry flue at 45 degrees and joined to the flexi liner somewhere up the wall, right where those (so carefully measured) studs are fitted in the corner.
Initial thoughts were take internal wall panels off (they don't go very far to the left or right). Reposition stud work away from the corner in the area that will need to be broken into the masonry flue and create a large access hole that can be later closed with hardibacker by the installer. Remove the old fire sides and back and make good the internal wall so a clean 90 deg corner can be reformed.
The Danish stove we had in mind, can be installed at 300mm clearance from combustibles at the sides, which means it will have to sit out in the room 300mm from the left and right walls and we'd line the corner with hardibacker to be safe in any case.. Stove is 1m high and 0.5 diameter. It's a large room, so that's all fine I think.
Questions:
1) Given the wall construction, Twin Wall flue pipe is necessary to go through the inner wall and into the flue (with at least 6cm clearance from combustibles all round) but will need to go in at 45 degrees to be compliant. Thus a 45 degree elbow will be required in the masonry flue itself and an Twin Wall adaptor to the flexi liner fitted inside the masonry flue. And all connected up inside the confines of the hole. Because of the depth of the inner wall insulation, a short length of twin wall will be required to bridge into the room. This leaves a joint inside the wall, which I understand is not allowed. But I cannot see how else the installer would connect to the flexi? So having doubts about feasibility of breaking into a stone wall with internal insulation for the stove configuration we'd ideally like.
2) I'm not sure if Twinwall is even allowed to connect to flexi? - most twin wall installations seem to continue on up to the cowl outside the house. Given we are in a church, that's not really an option either - so we have to exploit the masonry flue somehow. (which is clear and about 9" square).
3) If plan A fails and we can't have a free standing stove, I did think I could build a breeze block inglenook to house a more traditional British stove like a Charnwood C4. But then the corner position means that the lintel (such that is is) will probably be too low to allow sufficient offset in the vitreous flue pipes to connect to the stove, due to the corner situation.
Sorry for the length of the post, but hoping there is enough info there in case anyone has suggestions about how they would approach things?
In the process of sorting out a fairly shabby conversion of an 1843 Church. The plan was to remove a corner fireplace in the kitchen and install a free standing wood burning stove. The outline plan was to break into the chimney flue 2/3 of the way up the wall and connect to flexi liner to the top. We are at the prep stage, trying to make it installable before we get a HETAS guy to do the actual installation.
Anyway, this is what we've found having removed a cast iron fireplace front that had a wholly unusable "homebrew" and flammable decorative wooden surround.
The masonry flue is right in the corner, behind those double 4x2 studs.
As you can see, the walls are internally insulated - studs, celotex, 9mm osb, then plasterboard thus Twin Wall flue would need to be used to enter the masonry flue at 45 degrees and joined to the flexi liner somewhere up the wall, right where those (so carefully measured) studs are fitted in the corner.
Initial thoughts were take internal wall panels off (they don't go very far to the left or right). Reposition stud work away from the corner in the area that will need to be broken into the masonry flue and create a large access hole that can be later closed with hardibacker by the installer. Remove the old fire sides and back and make good the internal wall so a clean 90 deg corner can be reformed.
The Danish stove we had in mind, can be installed at 300mm clearance from combustibles at the sides, which means it will have to sit out in the room 300mm from the left and right walls and we'd line the corner with hardibacker to be safe in any case.. Stove is 1m high and 0.5 diameter. It's a large room, so that's all fine I think.
Questions:
1) Given the wall construction, Twin Wall flue pipe is necessary to go through the inner wall and into the flue (with at least 6cm clearance from combustibles all round) but will need to go in at 45 degrees to be compliant. Thus a 45 degree elbow will be required in the masonry flue itself and an Twin Wall adaptor to the flexi liner fitted inside the masonry flue. And all connected up inside the confines of the hole. Because of the depth of the inner wall insulation, a short length of twin wall will be required to bridge into the room. This leaves a joint inside the wall, which I understand is not allowed. But I cannot see how else the installer would connect to the flexi? So having doubts about feasibility of breaking into a stone wall with internal insulation for the stove configuration we'd ideally like.
2) I'm not sure if Twinwall is even allowed to connect to flexi? - most twin wall installations seem to continue on up to the cowl outside the house. Given we are in a church, that's not really an option either - so we have to exploit the masonry flue somehow. (which is clear and about 9" square).
3) If plan A fails and we can't have a free standing stove, I did think I could build a breeze block inglenook to house a more traditional British stove like a Charnwood C4. But then the corner position means that the lintel (such that is is) will probably be too low to allow sufficient offset in the vitreous flue pipes to connect to the stove, due to the corner situation.
Sorry for the length of the post, but hoping there is enough info there in case anyone has suggestions about how they would approach things?
