Flex stove pipe

[Jimbob]

I think it would be awful difficult to install a tee without a removable snout. How would you get it in there?
When I re-lined ours, I went with a tee with a removable snout. I haven't removed it since, though.

 

[Gooserider]

There are two applications where a "T" is used - for one of them, you pretty much have to have a removable snout, for the other a removable snout is NOT needed, and IMHO is rather a negative...

1. Relining a chimney, where the exit is in the side of the chimney wall, and the "T" is the part that comes through the wall. For this you basically have to have a removable snout of some sort, just as Jimbob says. You'd put the body on the end of the flex, slide it down and rotate until it lines up with the hole in the chimney, stick the snout in and fasten it in place... Depending on the size of the flue being lined, you'd HAVE to go with a removable snout because there is no other way to get a "T" in there. However since you are getting a lot of structural support and sealing from the chimney, air leaks are less of an issue.

2. Any application that uses a "T" in free air - such as coming off the back of a rear-vent stove. This is the sort of application that I have, and is not unusual for people putting a rear vent stove into a fireplace. The liner end is exposed, and the "T gets put on it after the liner was installed, and so there is no need to have a removable snout. In this case, there is no air sealing or support provided by the chimney, so a one-peice "T" is more desirable as it is less likely to have a problem at the joint between the body and the snout.

Gooserider

 

[theheatelement]

That is in no way a valid response.... their are not two different tee's for two different applications, the only reason is because some people build them differently. With your second response I will add that many individuals who have this type of system often use a removable tee because they install the tee to the liner or direct connector and then slide it down the chimney and install the snout in the hearth opening.. many times it is much harder to install the tee in the hearth opening as opposed to just installing on the roof and sliding it down.

There are two applications where a "T" is used - for one of them, you pretty much have to have a removable snout, for the other a removable snout is NOT needed, and IMHO is rather a negative...

1. Relining a chimney, where the exit is in the side of the chimney wall, and the "T" is the part that comes through the wall. For this you basically have to have a removable snout of some sort, just as Jimbob says. You'd put the body on the end of the flex, slide it down and rotate until it lines up with the hole in the chimney, stick the snout in and fasten it in place... Depending on the size of the flue being lined, you'd HAVE to go with a removable snout because there is no other way to get a "T" in there. However since you are getting a lot of structural support and sealing from the chimney, air leaks are less of an issue.

2. Any application that uses a "T" in free air - such as coming off the back of a rear-vent stove. This is the sort of application that I have, and is not unusual for people putting a rear vent stove into a fireplace. The liner end is exposed, and the "T gets put on it after the liner was installed, and so there is no need to have a removable snout. In this case, there is no air sealing or support provided by the chimney, so a one-peice "T" is more desirable as it is less likely to have a problem at the joint between the body and the snout.

Gooserider

 

[Gooserider]

That is in no way a valid response.... their are not two different tee's for two different applications, the only reason is because some people build them differently. With your second response I will add that many individuals who have this type of system often use a removable tee because they install the tee to the liner or direct connector and then slide it down the chimney and install the snout in the hearth opening.. many times it is much harder to install the tee in the hearth opening as opposed to just installing on the roof and sliding it down.

There are two applications where a "T" is used - for one of them, you pretty much have to have a removable snout, for the other a removable snout is NOT needed, and IMHO is rather a negative...

1. Relining a chimney, where the exit is in the side of the chimney wall, and the "T" is the part that comes through the wall. For this you basically have to have a removable snout of some sort, just as Jimbob says. You'd put the body on the end of the flex, slide it down and rotate until it lines up with the hole in the chimney, stick the snout in and fasten it in place... Depending on the size of the flue being lined, you'd HAVE to go with a removable snout because there is no other way to get a "T" in there. However since you are getting a lot of structural support and sealing from the chimney, air leaks are less of an issue.

2. Any application that uses a "T" in free air - such as coming off the back of a rear-vent stove. This is the sort of application that I have, and is not unusual for people putting a rear vent stove into a fireplace. The liner end is exposed, and the "T gets put on it after the liner was installed, and so there is no need to have a removable snout. In this case, there is no air sealing or support provided by the chimney, so a one-peice "T" is more desirable as it is less likely to have a problem at the joint between the body and the snout.

Gooserider

Possibly, but I'd TOTALLY disagree as to the suitability of the removable snout for an application where there is not a definite reason TO use it... At least the design that yours uses is a MAJOR air leak waiting to happen, I know as I've gone through the better part of a tub of refractory cement trying to get yours to seal at that joint. The one peice steel "T" it replaced was rusting out, and thus needed to be changed, but gave me NO problems with leaks at the junction of the "T"...

I know that I like my stove to draft, and air leaks destroy a stove's draft performance. I also don't want openings where smoke can come out into my house if something happens to restrict my chimney... I see absolutely no reason to ever consider an air leak desirable, and for that reason I will not reccomend a detachable snout "T" in a situation where it can be avoided....

You can try to sell whatever you like, however I will continue to advise against what I see as inappropriate applications where I think they compromise performance and / or safety...

BTW, my hearth configuration is more restricted than many, but the only problem I ran into installing your "T" with the snout attached, connecting it to the liner that was already in place, is that I was unable to get the three screws in at 120* spacing around the pipe - I ended up closer to about 80* between the three screws on the front, w/ no screws on the back - and it was a BEAR getting the screws drilled through the "T" and the liner adapter - SS is tougher than those "self drilling" pipe screws.

Gooserider

 

[jgoodnow]

Newbie here with a few basic questions about chimney liners.

1. Is an insulated liner intended to protect the surrounding masonry (safety) or to improve the draft of the chimney (performance)?
2. Is the insulation an integral part of the liner or is it wrapped around the liner at installation time? Is it Kaowool or another material?
4. What is the purpose of a double-walled liner? Is it in lieu of insulation or for a different purpose?
5. Round vs. oval liner. Why would you use one over the other?
6. Rigid vs. flexible liner. Is this mostly a matter of installation difficulty, i.e. rigid for straight runs and flex for runs with turns?
7. "304" vs. "316ti". Are these stainless steel alloys? Is 316ti better but more expensive?

I recently purchased a Jotul Kennebec wood insert and am waiting for the installation. I also bought a 25' stainless steel liner for $680. I'm assuming this is a rigid single-wall non-insulated liner, but I don't know for sure. I have a 25' chimney, the lower 10' of which is interior and the upper 15' of which is exterior. The chimney has an 8" x 12" clay-lined flue and seems to draft pretty well based on many years of open fireplace fires. My question is, what would be the best type of liner for my situation?

Thanks in advance for any advice. I'm sure some of the answers are to be found in prior threads, which I'll search.

 

[Gooserider]

Newbie here with a few basic questions about chimney liners.

1. Is an insulated liner intended to protect the surrounding masonry (safety) or to improve the draft of the chimney (performance)?

Both... It is a REQUIRED part of the installation if your chimney is not NFPA compliant to begin with - which isn't always easy to tell, and it will give an increase in safety even in a good chimney. It will also help to improve the performance of most chimneys, particularly exterior chimneys in colder climates. Warm climates and / or interior chimneys will get less benefit.

2. Is the insulation an integral part of the liner or is it wrapped around the liner at installation time? Is it Kaowool or another material?

It's an external blanket that gets wrapped around the liner, and secured with a special tape, then covered with a stainless mesh "sock" that is intended to protect it while sliding down the flue. I'm not sure just what the material is, but it's probably similar to Kaowool.

4. What is the purpose of a double-walled liner? Is it in lieu of insulation or for a different purpose?

Some rigid liner is double wall with insulation built in, so no external insulation is needed. In the case of flex it is claimed to be more durable / better safety, and / or give a smoother interior surface but does not substitute for insulation, and some claim that flexing the liner actually causes it to become less smooth than a single wall liner.

5. Round vs. oval liner. Why would you use one over the other?

Round is generally less expensive than oval, and may have greater cross sectional area for a given size (depends on whether it is a manufactured oval, or an "ovalized" round size) but can have problems going down some rectangular flues. Oval can fit better in such cases. In general, I would say use round if you can, oval if that's what it takes to fit... Some people will also ovalize the bottom few feet of a liner to get it past a damper or other restrictions in the smoke box area, however it is best to minimize this as much as possible.

6. Rigid vs. flexible liner. Is this mostly a matter of installation difficulty, i.e. rigid for straight runs and flex for runs with turns?

That's about it. In theory rigid is smoother inside so it will perform slightly better, develop less crud, and be easier to clean, but in practice it doesn't seem to make a lot of difference. Note that it is also possible to do a combined install with mostly rigid except for a few feet of flex on the bottom to get through the smoke shelf / damper area, and connect to the stove.

7. "304" vs. "316ti". Are these stainless steel alloys? Is 316ti better but more expensive?

Yes, those are the alloy numbers, with the "ti" indicating the presence of Titanium in the alloy. - the 316ti is generally considered the better of the two, although it does not appear that UL considers it so much better as to not need insulation in a non-compliant chimney.

I recently purchased a Jotul Kennebec wood insert and am waiting for the installation. I also bought a 25' stainless steel liner for $680. I'm assuming this is a rigid single-wall non-insulated liner, but I don't know for sure. I have a 25' chimney, the lower 10' of which is interior and the upper 15' of which is exterior. The chimney has an 8" x 12" clay-lined flue and seems to draft pretty well based on many years of open fireplace fires. My question is, what would be the best type of liner for my situation?

Thanks in advance for any advice. I'm sure some of the answers are to be found in prior threads, which I'll search.

I would try to insulate the top 15' or so, you don't have to get the same length insulation kit as you do the liner, and there isn't as much benefit to insulating the lower part of the chimney. However, you should note that your nominal 8x12 flue will actually be considerably less than that, so getting an insulated 6" liner down it can be a challenge. I've heard a few folks suggest that a 1 gallon paint can is about the same size as an insulated liner, so seeing if one can drop an empty can on a rope down the chimney can be a good "fit test".

I would also point out that in addition to the liner, you should definitely put in, or insist that the installers put in, a blockoff plate - there is a wiki article describing them, and I would consider that a vital part of the installation - to the point of saying it is a non-acceptable job if one is not put in. We've had multiple reports of people finding their inserts performing badly, and then getting great improvements after putting in the blockoff plate so their heat comes out into the room instead of going up the chimney.

Gooserider

 

[G-rott]

"deleted"

 

[jgoodnow]

Goose: great information, and quick too - thanks! I will follow up the insulation and blocking plate questions with my installer.

 

[theheatelement]

Goose quick question... I've asked my sales rep who has been in the industry for 30 years and he doesn't know who offers a welded base tee....duravent, flexmaster, everyone offers removable snouts... so what are you trying to say about the design of our base tee... I would like to clear up some of the information you are speaking of.

 

[Gooserider]

Goose quick question... I've asked my sales rep who has been in the industry for 30 years and he doesn't know who offers a welded base tee....duravent, flexmaster, everyone offers removable snouts... so what are you trying to say about the design of our base tee... I would like to clear up some of the information you are speaking of.

I am not sure of the brand on the "T" that I had initially purchased, it might have been Metalbestos, I'm not sure. But it was definitely stainless, and it was very definitely welded - not a continuous bead, but spot welds about every 1/2" or so all the way around the snout, as well as the seams on each part of the tube. Unfortunately I no longer have it in my posession, as I mentioned earlier, I swapped it to Elk when I was picking up my stove from him, in exchange for yours, because the length of the cleanout leg was shorter on yours - I hadn't appreciated the difference the welded joint would make.

For whatever it's worth departement, the stove I was running in that place, which came with the house when the GF purchased it about 15 years ago, had a single wall regular steel "T", which was also a solid single peice - I have no idea of the brand or equivalent.

Gooserider

 

[BrotherBart]

Gentlemen,

Stainless tees are made for masonry chimney relining ergo they are two piece construction to allow you to attach them to the liner and lower it into the chimney. Black pipe tees are for interior stovepipe installations and every one of them I have ever seen is one piece construction.

 

[Gooserider]

Gentlemen,

Stainless tees are made for masonry chimney relining ergo they are two piece construction to allow you to attach them to the liner and lower it into the chimney. Black pipe tees are for interior stovepipe installations and every one of them I have ever seen is one piece construction.

Except BB, that I had IN MY HANDS a one peice construction STAINLESS "T" - single wall, etc.... The stove place I bought it from had it as a stock item, and had no problem when I asked for a one peice stainless "T" - other than warning me that they weren't cheap....

Gooserider

 

[theheatelement]

Ok.. so we have come to some agreement.. and no longer are our base tee's subject to argument because all other manufacturer's use the same design as ours...

 

[tdziecho]

> Ok.. so we have come to some agreement.. and no longer are our base tee’s subject to argument because all other manufacturer’s use the same design as ours…

Except for the Heatfab PN 821670 fixed tee which I am about to use to install my rear vent VC Encore. If you don't believe
that other manufacturers offer a fully welded tee, buy one and have a look at it...

Winsurfer

 

[Gooserider]

Ok.. so we have come to some agreement.. and no longer are our base tee's subject to argument because all other manufacturer's use the same design as ours...

No we are NOT in agreement!

1. It is possible, indeed I would not be surprised, that all the other manufacturers offer a detachable snout base "T" - I haven't checked out their versions so I don't know if they are the same design or not (I'm not a mechanical engineer but I can think of several other ways to do the same thing, some of which might even be better...)

2. That they offer a detachable snout "T" does NOT mean that they can't ALSO offer a one peice Fixed "T" - Many thanks to Winsurfer for supplying one example of a manufacturer and part number.

3. You are ignoring the fact that I have actually had in my hand an example of such a stainless steel fixed "T" - I've handled one, so I KNOW it exists, and it certainly is NOT the same design as yours....

Gooserider

 

[theheatelement]

We at one time offered a welded base tee but no one ever bought it so we stopped offering it... yes it does exist our pellet vent kit's are welded because their all 3 or 4 inch but 5 and above are all detachable...

 

[Gooserider]

Dragging this back from the dead, as I now have some pictures to show the problem I'm talking about...

I am going into the stove problems elsewhere, and there are enough of those for sure, but here we look at the case of the Two-Piece Tee...

We start with the patient ready for examination -

Then move in for a bit closer look at the pipe setup - note that this is a strange setup in a way, as it's not a "fireplace". The clay lined chimney comes straight down, and ends at the base of the bricks. The stainless liner (brand and vintage unknown, was in the house when the GF bought it) sticks out the chimney, and the Two-PieceTee goes on the bottom of it, with the snout going into the back of the stove. Sort of looks OK at first glance...

But wait! Note the captions in the next picture...

Then we go in for a closeup of the top side of the joint - note the smoke stains, and the way the refractory cement on the joint has all flaked away...

But wait, there's more - we look at the BOTTOM of the joint in the next post...

Gooserider

 

[Gooserider]

Here are several shots of the underside of the joint - and in one picture I show how large the gap is by actually sticking my Leatherman tool into it...

Note that this is what happenned to Magnaflex's tee after just one season. I've now replaced it with a ONE PIECE WELDED base tee, made by Heatfab. I don't know if it's the Heatfab PN 821670 that Winsurfer found, as I don't see that number on the label I pulled off, but it is certainly stainless (looks like 304SS from the label), UL Listed, etc...

I don't know if this gap is why I got about five GALLONS of creosote out of my pipe when I cleaned it, plus almost completely blocking my chimney cap, but I'm sure it didn't help any...

Gooserider

 

[theheatelement]

That base tee has not been installed correctly. All of our base tees have a snout that has been pressed out where the tee attaches and it looks like on your installation you have modified our tee to fit your stove and have not installed the snout back onto the tee correctly. Their are two screws inside the base tee if those have been tightened down all of the way you will not have that gap. As I say again, we do offer a 1pc tee but we haven't had an order for it in the last two years, and we have not had a base tee returned to us because of a bad manufacturing process in the last two years as well.

 

[theheatelement]

From your installation I can tell you that your doing a couple things wrong. Your trying to make the base tee conform to the stove and as we all know a base tee operates one pipe vertically the other pipe 90 degree horizontally. What your trying to do is make the base tee adjust for say a 110 degree angle, what you need to do is move your flexible pipe to take up that gap so that your base tee doesn't have to. If you have any questions on installing it please PM me and I'd be happy to walk you through it.

 

[Gooserider]

1. The only modification to the Tee was to crimp the end of the snout so it would fit into the VC's stove connector.

2. The screws you are referring to were both as tight as they would go - i.e. the tabs on each peice were TOUCHING. I can go out and try to get a picture of the inside of the Tee right now (It's in my spares pile) and you would see that they are still touching - the tabs have BENT to give me the gap.

3. When I installed the Tee, the snout was properly centered on the protruding part of the base. The gap opened up over the course of the burning season.

That said, the liner with the Tee on it does hang down with the snout an inch or two below the stove exit - I had to push it back up into the chimney a little bit to make it line up with the stove. However this is the same way that it was setup on the original stove install, with a standard one peice steel tee - that had no problems, and the way that it's setup with the current one peice welded stainless tee from Metalbestos - that one hasn't been on for very long, but it shows absolutely no sign of flex, gaps, or any other issues.

Gooserider

 

[theheatelement]

bump................... ................................

 

[theheatelement]

Based on what your saying here that would have happened to any 2pc base tee because it was not installed correctly to begin with.. Is your liner not supported by something other then by the snout of a base tee attached to the back of your stove. Even with a welded piece you will eventually put enough stress on one part of the system tee or liner that something will break.

That said, the liner with the Tee on it does hang down with the snout an inch or two below the stove exit - I had to push it back up into the chimney a little bit to make it line up with the stove. However this is the same way that it was setup on the original stove install, with a standard one peice steel tee - that had no problems, and the way that it's setup with the current one peice welded stainless tee from Metalbestos - that one hasn't been on for very long, but it shows absolutely no sign of flex, gaps, or any other issues.

Gooserider

 

[Gooserider]

My assumption is that since the whole thing doesn't come sliding down the chimney, there must be some support at the top. (I don't know for certain, as *I* have never been up to the top of the chimney myself - I clean from the bottom (and so does the sweep.) The sweep has been up to the top a couple of times (and was NOT happy about it) but hasn't gone into a detailed description of whats up there.

I refer to our chimney as a "Vermont Chimney" as it verges on "You cahn't get theah from heah.." It's around 25 feet inside from the end of the liner to the top, and ground level is probably at least 6-8 feet lower - If you look at the picture, that's a 36' extension ladder extended all the way leaning against the side of the house, with at least another 6-8 feet of stack above it. When the sweep goes up, he has used three ladders - one to get up on the porch (about where the ladder is in the second picture) a second ladder with a roof hook to go up the main roof on the inside of the chimney, and a third step ladder on the high side of the roof leaning against the chimney - NOT a happy making combination.

I think it might be possible to get up in one step if I had a 40' extension ladder - or at least it would get up high enough to go directly from one ladder to a stepladder on the upper side. But still not exactly a happy top to get at.

Gooserider

 

[branchburner]

Even if the liner has support at the top, the fact that it was pushed up an inch means the weight of it is resting on the tee, and the tee alone is supporting the liner (unless/until it sinks back down an inch). That pressure would put the pivot point on the top seam (and explain the smoke leakage there, as well as the gap on the bottom seam).

Maybe you could cut the bottom inch off the liner instead of pushing it up?

Love your house, but I don't know if I'd like working on that roof, either!