Lining chimney - Conflicting information

Pique

Hi,

I am looking at geting my chimney lined as part of the work to rebuild the stack on the roof.
I spoke to 2 different guys whose business this is and got conflicting information from both so I'd like you to hear me out and let me know which one is right and which is dodgy.

The details:
100 year old stone farmhouse (similar to this, but only 3 windows wide instead of 5 http://www.irishlandmark.com/wp-content/uploads/2014/11/inchaquin_featured.jpg)
Chimneys never had flue liners fitted.
Upstairs rooms had fireplaces back in the day but have been closed off for donkeys years now.
There is a bend in the chimney to accommodate this feature.
Chimneys are internal, not on the gables.
Back boiler with open fire.
Now the difference of opinions.
Builder 1 said:
No problem, we put in a 'starter flue' inverted cone shaped thing the width of the existing chimney feeding into a flexible flue and them pack out the cavity with Vermiculite or whatever. 
Builder 2 said.
The chimney isn't straight so flexible flue is the only option. However you need a 9" (I think he said 9", maybe it was 8") for an open fire. Chimney isn't big enough to accommodate 9" liner and the only other option is 6" which is only for stoves. If you put a 6" one in (which will fit) you are breaching fire regs by using it with an open fire.

So is Builder 2 correct about the fire regs bit?
Is it possible that Builder 1 reckoned a 9" liner would fit but builder 2 disagreed because of the lack of ample surrounding area for vermiculite(I'm assuming there are rules on the thickness of vermiculite required to surround a flue)?

jack of all

Flue size is governed by Irish building regulations, Technical Guidance Document J, 2014. A 150mm flue will serve a stove up to 20kw rating, an open fire requires a 200mm flue. If there is any doubt about getting a flue liner through the existing chimney stack (200mm would be unwieldy enough I'd guess?) you'd be best to go with 150mm liner and stick with a stove- easier to fit, less expensive and allows for a decent bit of vermiculite bedding around the flue. Stove is the only way to go anyway- more economical, cleaner and no draughts when not in use, open fires will be a thing of the past very soon anyway once new proposals for zero energy buildings comes into force in the next couple of years.

antiskeptic

Pique wrote: »

Hi,

I am looking at geting my chimney lined as part of the work to rebuild the stack on the roof.
I spoke to 2 different guys whose business this is and got conflicting information from both so I'd like you to hear me out and let me know which one is right and which is dodgy.

The details:
100 year old stone farmhouse (similar to this, but only 3 windows wide instead of 5 http://www.irishlandmark.com/wp-content/uploads/2014/11/inchaquin_featured.jpg)
Chimneys never had flue liners fitted.
Upstairs rooms had fireplaces back in the day but have been closed off for donkeys years now.
There is a bend in the chimney to accommodate this feature.
Chimneys are internal, not on the gables.
Back boiler with open fire.
Now the difference of opinions.
Builder 1 said:
No problem, we put in a 'starter flue' inverted cone shaped thing the width of the existing chimney feeding into a flexible flue and them pack out the cavity with Vermiculite or whatever. 
Builder 2 said.
The chimney isn't straight so flexible flue is the only option. However you need a 9" (I think he said 9", maybe it was 8") for an open fire. Chimney isn't big enough to accommodate 9" liner and the only other option is 6" which is only for stoves. If you put a 6" one in (which will fit) you are breaching fire regs by using it with an open fire.

So is Builder 2 correct about the fire regs bit?
Is it possible that Builder 1 reckoned a 9" liner would fit but builder 2 disagreed because of the lack of ample surrounding area for vermiculite(I'm assuming there are rules on the thickness of vermiculite required to surround a flue)?

The 6" is for a stove, the larger (9") in my 100 year old house, for a coal fire. The starter bit is a collector. It basically an inverted funnel, collecting over the area of the fire and narrowing to a circle onto which the flue. In my house, the collector was fashioned in brickwork but now they are cast concrete units. You need one.

After a chimney fire and a cracked flue, I had a steel liner put in (8" down the 9 inch flue). The breast had to be opened above the fire place to connect this liner to the brick. I can't recall if vermiculite was installed

One of the chimney crowds offer a flexible (not steel) liner which they drop down the flue and pump up it out to follow the contour of the existing flue then cure it hard with (I believe) steam. You retain the diameter you've already got. They did a good enough job on my job (even if I didn't get the aforementioned liner) so PM me if you want a name. An option perhaps.

Would you be breaking the regs working with the flue diameter you've got? I doubt you can apply modern code to stuff made before the code was introduced?

Pique

The thing is, I've bought a fire door to use with the back boiler rather than the unneeded expense of a ton of work removing the back boiler, fitting the stove (inset would be the most suitable considering the fireplace) not counting the cost of a 15-18kW boiler stove.

What's your take on the differences in opinion between the 2 builders though. Both have chimney repair businesses FWIW. Builder 2 is more known to me as he is more local and has done work on houses of people I know, so reputation counts too, but also the fact that he's being more cautious. 
However, a non-lined chimney in a hundred year old house doesn't fill me with hope for the future. In the past, it was 100% turf fires. Since the ban on turf cutting it's harder to get turf and coal would be more used, which to me (dunno if true) raises the risk of a buildup of soot/creosote/tar/whatever in all the nooks and crannies of an unlined chimney and therefore, chimney fires. That's the reason I was considering the lining int he first place, once the stacks had to be rebuilt.

Pique

antiskeptic wrote: »

The 6" is for a stove, the larger (9") in my 100 year old house, for a coal fire. The starter bit is a collector. It basically an inverted funnel, collecting over the area of the fire and narrowing to a circle onto which the flue. In my house, the collector was fashioned in brickwork but now they are cast concrete units. You need one.

After a chimney fire and a cracked flue, I had a steel liner put in (8" down the 9 inch flue). The breast had to be opened above the fire place  to connect this liner to the brick. I can't recall if vermiculite was installed

One of the chimney crowds offer a flexible (not steel) liner which they drop down the flue and pump up it out to follow the contour of the existing flue then cure it hard with (I believe) steam. You retain the diameter you've already got. They did a good enough job on my job (even if I didn't get the aforementioned liner) so PM me if you want a name. An option perhaps.

Would you be breaking the regs working with the flue diameter you've got? I doubt you can apply modern code to stuff made before the code was introduced?

Your house sounds similar but the chimney size in yours allowed the 9" liner. Builder one said it was fine, Builder 2 said it wouldn't fit.
Builder 2 said he wouldn't put in a 6" if I was using an open fire as it was against building regs and if anything happened, it's his ass on the line legally (but mine physically I suppose!).

Right2Write

Old 2 storey house here, chimney with bend as it narrows upstairs etc. We used a 6" flexible liner and connect to a stove with back boiler. I fitted the liner myself - it was a 'bastard' of a job. Despite the smaller diameter of the liner, getting it up through the bends was an exercise in soot, dirt, patience and lots of exits onto the roof. Eventually made a small opening in the brickwork near the constriction so as to be able to ease the liner up. Worth it though as prior to that, there was a noticeable smell in the rooms upstairs adjacent to the chimney. If I ever have to replace it, I'll be paying someone!!

Calahonda52

OP:
What exactly does this mean:
I am looking at geting my chimney lined as part of the work to rebuild the stack on the roof.

Pique

The chimney stack (the bit above roof level, apologies if this is not correct terminology ) needs to be rebuilt due to damage, so as part of the work I figured now is a good time to see about the possibility of having one lined.

Calahonda52

Pique wrote: »

The chimney stack (the bit above roof level, apologies if this is not correct terminology ) needs to be rebuilt due to damage, so as part of the work I figured now is a good time to see about the possibility of having one lined.

Thanks
Well maybe consider having it all rebuilt/relined with either ceramic or pumic liners because relining with SS flexi is not a lifetime job, depending on what you burn etc etc as well as the quality of the liner, quality of the vermiculite lining it might only last 5 years, especially if its fitted through a bend.

[I know lads and lassies will jump in here at the 5 year number: its based on my experience...}.

antiskeptic

Pique wrote: »

Your house sounds similar but the chimney size in yours allowed the 9" liner. Builder one said it was fine, Builder 2 said it wouldn't fit.
Builder 2 said he wouldn't put in a 6" if I was using an open fire as it was against building regs and if anything happened, it's his ass on the line legally (but mine physically I suppose!).

Check out the one mentioned then, which expands out to the size of your existing flue diameter (which is presumbly large enough for an open fire). PM sent

ballystephen

If you can sweep it you can stick your exhaust from your woodburner into the flue and pack around it with rockwool . Job done minimum cost
Regards

Sausage dog

We've had experience of old chimneys which were unlined. The flue was red brick & porous or crumbly & not safe for use as an open fire. We also had floor joists going into the chimney breast which isn't such a good idea in the event of a chimney fire. We used a 6" flexible liner inserted from the roof, (apparently the weight of it helps it move down the chimney) and a 7" flexible liner. We will use both with stoves. Holes were made in the stonework at intervals to help move the new flue down the chimney as our chimneys were quite narrow.

Calahonda52

ballystephen wrote: »

If you can sweep it you can stick your exhaust from your woodburner into the flue and pack around it with rockwool . Job done minimum cost
Regards

Complete XXXX and dangerous advice unless the wool os designed for that purpose

http://www.engineeringtoolbox.com/insulation-temperatures-d_922.html
shows the temperature limits for comma gardener glass fibre/mineral wool etc
which are much lower than what you will get in the stove flue