Need Advice On Woodstove Chimney Liner Installation

[Newwoodstoveowner]

Help....I am being told all kinds of conflicting things

A...One person states a heavy duty corrugated liner is better than a smoothwall 316-L type liner because the spiral of the corrugation helps spin the smoke and help it rise. But the smoothwall seems more heavy duty, this person says no matter, both are stainless steel and guarranteed, other says corrugated will collect creosote and be harder to clean.

B...One is going to jackhammer the throat (flue damper area) as neccesary to keep the pipe round to connection (this one using smoothwall 316-L) other will give me corrugated which he reccomends or smoothwall if I want it no extra charge, but states ovalizing the pipe to fit through damper area the way to go because if you ever want to make it a fireplace again your damper area now compromised and would need to be rebuilt. This person also sates ovalization through damper area will not affect draft and performance

C...All seem to agree having the liner insulated not neccesary due to me not being in a very cold climate, they will insulate the damper area where the pipe does not pass through, however.

Stove is a Hearthstone Clydesdale Woodstove Insert, chimney all brick and exterior.

Which way is the right way....?

 

[Wet1]

A: Smooth is better if you can use it. The "spin" theory is BS. Spiral will be harder to clean.

B: Either way works, no issues with either method as far as performance goes.

C: If given a choice, I'd say insulate it to meet code, plus give better draft, and have less creosote.

 

[branchburner]

My take:

A...Either is fine, the smoothwall is more heavy duty, corrugated is marginally harder to clean - I'd go smooth if it's a straight shot

B... jackhammer? or just cut the damper frame? it is true if you ever want to make it a fireplace again you would need to fix it, and ovalization through damper area should not affect draft and performance, but ovalization may make it harder to clean since it's an insert

C... having the liner insulated not neccesary but highly recommended for max heat due to exterior chimney

 

[Newwoodstoveowner]

Thanks for everyone's advice, I will probably never use it as a fireplace after stove intallation, but just wondering if I ever sell the home a new owner may want it. Will heavier duty smoothwall be able to be ovalized through damper area? I am thinking that the quote I got with the heavier smoothwall the person will jackhammer or cut opening due to liner not being as flexible.

I just hope I have an opening wide enough to include insulation on the liner, winters here do not get overly cold and I am very near the water. What about condensation and/or water getting to insulation?

 

[Wet1]

No, you can't ovalize the rigid smooth wall. You can go rigid and then flex at the end through the damper. But I wouldn't worry about saving the damper.

You'll have a plate that seals the liner at the top, water will not be much of an issue either way.

 

[philaphire]

Excuse my insensitivity, but that's the new owners problem if s/he wants to make where the stove is back into the fireplace. I had to cut my damper in order to get the liner in and wouldn't recommend ovalizing as that affects draft & cleaning. Jack hammering sounds so intrusive - what material is the damper? My hunch is that most are cast iron so either a sledge if you can get in there or recriptocating saw/angle grinder will do the trick. Many on this forum have done it so you can search for other people's stories. I have an interior chimney so I didn't have to worry about insulation - but the insulation is ceremaic wool with a foil backing and I wouldn't think condensation is a problem and as for water that's what the chimney cap is for.

 

[Newwoodstoveowner]

The smoothwall liner is not rigid, it can flex just not as much as the corrugated, it seems the bricks and masonry come right up to the metal part on the damper opening leaving only about 4" to pass through the damper opening so some masonry demolition would occur to open it up enough not to ovalize.

 

[Wet1]

If you're talking about the double wall flex, you're not ovalizing that either.

 

[Newwoodstoveowner]

I think it is single wall, it is called "Superflex" 316-L liner, the outside is just as rough as the outside of the corrugated liner which is rough surface on both sides, the 316-L is flat and smooth on the inside. It reminds me of "Flat Wound" bass strings for an electric guitar, if you could take one of these strings and tightly spiral it onto a round tube shape.

 

[BrotherBart]

You don't want to try to ovalize the smoothwall flex. The interior spiral will de-laminate leaving gaps. Been there and done that and ended up pulling it out and replacing it with single wall flex. If you can do a straight shot down and don't need to ovalize it it is great stuff.

 

[gpcollen1]

I used the Duraliner [double wall/insulated] with the oval-flex piece going through the damper. no real cutting to speak of and I would recommend this installation 1000%.

 

[Newwoodstoveowner]

Yes it is pretty much a straight run down with about a 30 degree turn at the last bottom part to direct through the damper area into the fireplace. I assume without ovalizing the smoothwall flex can handle the 30 degree turn...? It does look like it would open at the seams if you tried to ovalize it, at least without using an ovalizing roller tool. I am beginning to think the smoothwall with the damper demolition is the better job.

I will also look into the Duraliner, but am limited in budget and what the installers use with regard to product.

 

[BrotherBart]

Flex is kind of a relative term with the smoothwall. I used a stainless elbow to make the turn down into the stove because that thick liner won't make a short radius turn. Within a foot or so of its length you are not going to bend it.

 

[jdinspector]

...the spiral of the corrugation helps spin the smoke and help it rise.

What a load of crap. I'd be careful of this person's advice. Sounds like classic salesman BS