help deciding type of chimney liner

[rmcfall]

I have a masonry chimney on an exterior wall that runs straight up without any bends in the flue. I am wondering whether I should install a (1) flex liner wrapped in insulation, (2) install rigid pipe wrapped in insulation, or (3) install double wall pipe with insulation factory installed inside the walls (expensive and probably unnecessary)?? My goal of course is to insulate the chimney as best as possible since it sits on an exterior wall. Any suggestions? Any suggestions on brand?

 

[Shane]

Brand names I won't go into there are many fine ones out there. Optimally I'd go with the double wall, you don't have to attach any insulation and the walls are smooth not corrugated. Second choice I'd go with the single wall ridgid. Thirdly (which is what our company installs most of the time due to price) I'd go with the corrugated insulated stuff.

 

[MountainStoveGuy]

Shane, this might be myth, so someone please correct me, wont double wall condensate between the two walls? Or is that coaxial gas pipe.

 

[Shane]

not sure. I suppose it could, I've installed alot of it and it holds up quite well. It's really heavy is the only thing I don't like about it. Definately need a collar to install it if your going over 15' or so.

 

[Mo Heat]

I have a masonry chimney on an exterior wall that runs straight up without any bends in the flue.

If I remember correctly, you are located in either Georgia or Kentucky. I'm in Missouri and I think we have similar climes. I also have an external masonry chimney that goes straight up for about 23 feet. I burn a cat stove that may not draft as freely as some non-cat stoves (unless I'm trying to damp it down, then it drafts like crazy!).

I haven't cleaned my chimney this year (yikes) but will soon, however, last year there was about a half of a gallon of creosote. Nice, dry, powdery, creosote. Some of it was likely just ash. I'll try to give an update when I clean this year, when it gets below 200*F on the roof!

If you are in Georgia, I doubt that you'll need insulation on your liner. Well, not unless you are on a hill, exposed to the unhindered north wind, next to a pond, etc., etc. Or if you have an extrememly short chimney with a really poor drafting stove.

So unless there are special circumstances, I'd save the money and go with a rigid, uninsulated liner. Judging by the difficulty of pushing a plastic chimney brush through a smooth walled liner, I suspect a corregated liner would be even worse. Of course, if you don't clean your own chimney, that isn't much of a consideration.

Disclaimer: I'm not a professional. Don't heed my advice.

 

[Shane]

I would just make sure the liner you choose (if you install it uninsulated) doesn't require the insulation to retain the UL1777 listing.

 

[Todd]

E-Bay has liners for sale cheap. Look for the 316 stainless, I think they are UL listed without insulation?

 

[begreen]

Where are you located? I have an 8" ss liner lying on the lawn and looking for a home if you are in WA state.

 

[rmcfall]

Thanks for the feedback everyone. We were in Georgia, but are now back in Kentucky. With my previous stove (in KY) I installed a flex liner wrapped with insulation and it did have some creosote when I cleaned it, but nothing too terrible. I used a plastic brush and it actually wasn't too difficult to push the brush up and down... In my current scenario, cleaning will be even easier because my chimney is a straight shot up and down. I figure I will insulate since the cost isn't that much more. I suppose there isn't a huge advantage of using the flex liner instead of the rigid since my chimney runs straight up and down...

 

[Todd]

If your flue is straight and has no obstructions I would go with the rigid liner over flex. Smoother, better draft, and easier to clean than flex.

 

[rmcfall]

Shane, this might be myth, so someone please correct me, wont double wall condensate between the two walls? Or is that coaxial gas pipe.

I am getting ready to finally make my liner purchase and was thinking about getting Rhino Rigid liner from this place: http://chimneylinerstore.com/xcart/home.php?cat=7 . The 316 isn't that much more than the 304. That said, I want to go ahead and insulate the liner, even if it is overkill. The thought of installing rigid insulated pipe seems like it might get kind of tricky. Thus, I am wondering whether I should go with double wall insulated? Is it true that it will condensate between the walls? If insulating rigid, is there some trick to getting it down the chimney? I've done the flex before and it was easy. The rigid seems like it would be much harder...