woodburners & insulation fo chimney

[Penners]

I agree, MdB. The ideal installation consists of a metre of enamelled stove pipe running up through a register plate, attached to the rest of the vertical flue in insulated liner.

 

[Moneypit]

We have installed liners in two chimneys, the flues are approx 10" x 10" and ground floor to chimney pot is about 11m. We back filled with vermiculite and it did take a lot, about ten 100 litre bags I think so quite expensive. One reason for using the vermiculite was the belief that it would provide the best support for the liner, especially important for future liner cleaning. The woodburner lights easily and quickly.

 

[DJH]

That's how I used to do it but mixed with lime or Walcrete which was a weak cement no longer available now I think. It's been common practice more or less forever to connect stoves to chimneys via stove or flue pipes to both cool flue gases and take advantage of the heat given off to heat the room where the appliance was situated.

Doug

 

[Bayliss]

Nobody has mentioned this method of forming a new flue inside an existing chimney which I've seen used on quite a lot of occasions on historic properties I've worked on where removing and destroying historic fabric to access the chimneys has been judged unsuitable. This method involves sending an inflatable tube down through the chimney where it is sealed at the fire opening and then inflated. A pumice mix ( I'm not exactly sure of the hardening material) is then pumped from the chimney down alongside the inflated tube filling the void between it and the structure.

I know that the first think everyone will think is that there could be places where the tube touches the masonry and the mix will not surround the pipe at these places but it was thought that this was a small price to pay rather than have any demolition work which would have to take place to insert flue pipes. I seem to recall that a camera was also sent down the chimney both before the works were carried out. Not too sure of the costs of using this method but to maintain the integrity of the structure it was thought the best option and maybe cheaper in some cases and, of course, quicker and an added bonus that the stack is reinforced at the same time.

Doug

We considered this method of flue lining many years ago, decided against it when we were advised to consider the weight of the material and the relative weakness of an old stand alone chimney flue. Perhaps other more experienced posters could comment on this.