Rigid vs flex liners

[Watchguy]

OK, you convinced me. Doesn't sound like either are all that great. I'll just start over with fresh, good quality factory chimney.
I was just trying to not spend another fortune on chimney. All in all I think I'll still be ahead burning wood rather than propane. The payback will be just a little further down the road.

 

[Charles1981]

I guess my question is you have an 8inch liner already. Are there problems with it that make you want to one replace it and also downsize to 6 inches?

Edit: or am i mis-reading and you have a 8inch unlined or clay lined chimney?

 

[Watchguy]

Right now I have an 8" Selkirk ultra temp chimney (no liner) and any of the stoves I'm considering require a 6" chimney. So I need to downsize. I considered installing a liner to save cost and labor but it sounds like it will save neither. For a little more money I can get Ventis, ICC Excel or Duratech. I could go with Ultra Temp again but am wanting a slight upgrade. Kinda like underwear, I want a comfortable fit.

 

[_CY_]

actually heavy wall flex liner is much heavier than rigid liners. and I have seen many light wall liners both smooth wall and regular that have been completely burnt through. one in 2 seasons. only seen 2 heavy flex liner burnt through and one rigid that was not exactly burnt through but it was melted at the bottom and collapsed on it self. rigid is probably a little more durable than heavy flex but not by much and like chimneysweep said those seams can definatly be a problem. and if you use rigid make sure you assemble it right side up or you will have creosote running down the out side eventually and that is a really bad situation.

the Majestic 8in stainless rigid I just installed was very thick .. if flex was made that thick that would be some good stuff and barely bendable.

 

[Benchwrench]

I realize the damage shown in this post was most likely due to frequent over-firing, and the liner brand and model was never identified, but when I see stuff like this I'm glad I tend toward overkill. I feel pretty good with that tank of a liner in there.
https://www.hearth.com/talk/threads/liner-pic-i-am-stumped-and-discouraged.109403/
...

That picture looks like the flex buckled due to improper installation.
It resembles crushed pipe from not being supported from up top.

 

[Hogwildz]

I stand by my view on the rigid. It is much heavier than any flex I ever installed. And no problems with air infiltration as it is double walled and slips over each end both inner and outer. Mine came pre drilled and with stainless rivets. 8th season and not a problem. smooth inside and cleans very easily. The only problem I have had is the capo screen was not stainless and is now rotting thin. Already have some to replace it with.
I'd do it the same all over again the same way given the chance.

 

[_CY_]

I stand by my view on the rigid. It is much heavier than any flex I ever installed. And no problems with air infiltration as it is double walled and slips over each end both inner and outer. Mine came pre drilled and with stainless rivets. 8th season and not a problem. smooth inside and cleans very easily. The only problem I have had is the capo screen was not stainless and is now rotting thin. Already have some to replace it with.
I'd do it the same all over again the same way given the chance.

that's what I'm thinking too .. the 8in stainless rigid just installed felt slight heavier than 26 gauge. those interlocks are not coming apart without beating on em .. 30degree elbows had no interlock, those were screwed down.

felt like a lifetime liner to me, not much chance of burnout anytime soon if ever.

 

[bholler]

I am sorry but allot of you guys seem to be talking about insulated chimney systems that is a totally different product for a rigid liner we are talking about we are talking about a single wall rigid pipe you put inside a chimney. of course double wall insulated chimney will be much heavier than a single wall flex liner

 

[_CY_]

I am sorry but allot of you guys seem to be talking about insulated chimney systems that is a totally different product for a rigid liner we are talking about we are talking about a single wall rigid pipe you put inside a chimney. of course double wall insulated chimney will be much heavier than a single wall flex liner

can't speak for anyone else, but I've been talking about the stainless steel liner found inside a Majestic double wall pipe. which can be used in double wall configuration or stainless liner by itself.

8in stainless liner is about .020in vs .006in for regular stainless flex and .015in for HD stainless flex.

best of all if you can find the Majestic double wall liner in stock locally. with no shipping costs is substantially less than online. which has to factor free shipping into price. for a 4ft section of 8in Majestic double wall local cost was $40 vs about $90 online price.

 

[swestall]

While not "optimal", there are many installations with new 6 inch stoves using an adapter into an 8 inch stack with good results, no? If you intend to buy a specific stove you might want to try that approach as it won't cost much (bet the dealer will give you the adapter). And, you can always change after if you have to.