newbie with a questions about rigid liners and insulation in old (1800's) chimneys

[NHFarmer]

I used Foreverflex 7" liner.I found a calculator to calculate the amount of insulation needed on one of the liner supplier's websites.I don't remember which one it was.The insulation is not cheap but it did give me a UL listed assembly

 

[branchburner]

TherMix seems like a reasonable solution at an unreasonable expense. A poured-in flue sounds good, but isn't there a chance it could crack or otherwise fail?
While a standard liner w/ blanket would do the job, I like the idea of filling some if not all that extra airspace in the top half of the chimney. It seems like even with a block-off and top seal, you could have a convection loop as the flue warms, bringing warm air up to lose heat to the cold brick exposed in the attic and above the roofline.
TherMix is UL listed, but if a homemade version could meet any code or insurance needs, I bet it could be done at a fraction of the price.

 

[fraxinus]

For an unlined chimney of this age, a poured in place liner is by far the best solution. A stainless liner will not do anything to enhance the structural integrity of what is now a 200+ year old chimney. I fully understand the cost issues, but when you add up ss liner, insulation, labor etc., I found Supaflu (which comes with a lifetime transferrable warranty) to be price competitive. Spending the extra money (if it is extra) now, if it is at all possible, will give you a lifetime repair and great peace of mind.

 

[nscarnati]

For an unlined chimney of this age, a poured in place liner is by far the best solution. A stainless liner will not do anything to enhance the structural integrity of what is now a 200+ year old chimney. I fully understand the cost issues, but when you add up ss liner, insulation, labor etc., I found Supaflu (which comes with a lifetime transferrable warranty) to be price competitive. Spending the extra money (if it is extra) now, if it is at all possible, will give you a lifetime repair and great peace of mind.

ballpark, what would a supaflu liner cost? I know every job is different, but what is the minimum cost?

 

[fraxinus]

Five years ago, I paid $1500 for a Supaflu liner in an old unlined chimney of about 30 total feet. Your best course would be to find a local dealer at www.supaflu.com, contact him and see what the current price would be in your area.

 

[nscarnati]

Five years ago, I paid $1500 for a Supaflu liner in an old unlined chimney of about 30 total feet. Your best course would be to find a local dealer at www.supaflu.com, contact him and see what the current price would be in your area.

thanks - my chimney's about 24 feet, if I could still fnid supaflu that cheap I'd definitely go that route. Having a hard time getting a response back from supaflu to find out who deals it locally, but i'll keep trying. hopefully in the 'recession' contractors might be willing to lower their prices slightly to get the work...

 

[nscarnati]

The idea is to run a chimney inside your current chimney - the only reason you need a liner is to complete the old chimney you have now. If you ran a new chimney (even if you did it inside the old one), you wouldn't need a liner.

Does it meet code to use an old chimney as a chase? I thought I read somewhere you can't put class-a chimney pipe inside of a chimney, as it was against code for some reason I couldn't understand. Anyone know why this is against code, if it is?

This would probably be easiest for me to do if legal, and I would think class-a chimney is safer than double-walled relining pipe