Flue Liner Question

[jbrown56]

I was lookng at the flue liner kits at the vendors on this site and I have a few questions. I saw three types, corregated, corregated with smooth inertior walls and rigid. The rigid being the most expensive is probably out of the question but probably the best. What would best choice between the remaining two. Also should I have the dealer install this, although the cost seems somewhat high or should I buy a kit and install myself being a homebuilder and quite confident of my ability. After dropping 2K on a stove installing the chimney too really blows the budget!

Jim

 

[zzr7ky]

Hi -

I went with Rigid. Easy install in 12" square tile. Smoother interior will clean easier and flow better.

I see no reason not to install it yourself if you can get to the top of the chimney with the liner. Install of liner was not hard.

ATB,
Mike P

 

[Nebrsmithers]

I have recently researched the same topic. I choose the flex liner made by Forever flex. (TheChimneySource.com) Nice people! They customized the kit to fit my needs exactly. First, they offered to ovalize the last 3 feet of flex so that it would fit easily thru the damper to the stove. Second, they swapped the standard round quick connect for a round to oval stove to liner connect. And finally, they exchanged the standard top plat for a terracotta top plate because it would work better for my situation. Add to that, the fact that they threw in the high temp silicone and a pair of gloves and then took 10% off the price of the kit, well it seemed like a no brain-er.

One side note, in my reading I was lead to believe that the "double wall" flex with the smooth interior suffers if you try to bend or manipulate the liner. The interior "smooth" wall will crack if you try to do this. NOT my experience, just information I got off the web.

 

[theheatelement]

We have made both smooth interior flex pipe and corrugated and frankly unless we were to ship the pipe as a standard 25 or 35 foot long piece then it wouldn't be an issue but when you roll the smooth pipe what happens is the inside of the smooth side flairs up on one side... and then ends up catching cresote anyways... so the standard is simple corrugated pipe with 24 gauge fittings. If you have any questions, please feel free to ask me...

 

[Gooserider]

I was lookng at the flue liner kits at the vendors on this site and I have a few questions. I saw three types, corregated, corregated with smooth inertior walls and rigid. The rigid being the most expensive is probably out of the question but probably the best. What would best choice between the remaining two. Also should I have the dealer install this, although the cost seems somewhat high or should I buy a kit and install myself being a homebuilder and quite confident of my ability. After dropping 2K on a stove installing the chimney too really blows the budget!

Jim

At least in theory, the smoother the interior, the better the stove will draft, as the bumps cause turbulence which restricts the flow. Because the draft is better, a smooth liner will collect less creosote. When you clean it, a smooth liner is easier to push the brush through.

The best is rigid if you can afford it and you have a straight chimney that allows you to use it. The smooth inside flex is second best, with the corrugated being 3rd in terms of desirability. In practice a lot of folks end up with corrugated, and we don't see complaints about it.

One advantage to at least some of the rigid brands is that they are pre-insulated, and a bit smaller in OD than flex with an insulation jacket... This can compensate for some of the cost difference between rigid and flex, and make the install easier when going into a tight flue.

As to doing it yourself, it is not a terribly complex process, if you can read (and follow) instructions, and are a home builder, you should have no problem at all doing it yourself.

Gooserider

 

[BrotherBart]

We have made both smooth interior flex pipe and corrugated and frankly unless we were to ship the pipe as a standard 25 or 35 foot long piece then it wouldn't be an issue but when you roll the smooth pipe what happens is the inside of the smooth side flairs up on one side... and then ends up catching cresote anyways... so the standard is simple corrugated pipe with 24 gauge fittings. If you have any questions, please feel free to ask me...

The man speaks the truth. I spent a fortune on the smooth-wall flex pipe and when it was un-coiled for installation the "flairs-up" thing occurs big time. With a twenty-five foot piece. Creosote catching de-laminations all the way up the pipe. I pulled the thing after one season and tossed it in the landfill and replaced it with a single wall liner. The other Catch-22 (if you are old enough to remember that) is that no standard adapters, flue collers or anything else fit the stuff because of the exterior dimensions. Another $150 down the drain.

Very disappointing because the stuff is built like a tank. But I also defy anybody to be able to install it from the top of a chimney because it is so stiff I had to push it up from the bottom.

Outside of that I have no opinion.

 

[elkimmeg]

I have used Magnaflex kits the last two installations. I will be purchasing their product again for the next installation.

 

[BrotherBart]

I have used Magnaflex kits the last two installations. I will be purchasing their product again for the next installation.

Simpson Duraflex liner rocks! And the cap ain't ugly.

 

[webbie]

Funny, it used to be that rigid cost less than flex - but they have thinned out the flex more and more over the years, and now it is 1/4 to 1/4 as thick as the rigid. A combination of flex and rigid is often a good choice if you need flex through the damper area (fireplace)....

My suggestion is to spend a little more if you are going to be in the house for a long time. For instance, if the vendor offers two thicknesses, go for the thicker (with flex). There are also some premium processes...most flex is simply pressed together, while some (ventinox?) is welded...obvious a difference if true.

Very typical for folks to over-spend on the stove and then try to get away cheap on the stack....but think about it, that is like spending big on the engine, and going cheap on the tires!

I suppose I am shoveling chit against the tide, cause it seems everyone wants the $300 aluminum foil thickness liners.

 

[theheatelement]

Funny, it used to be that rigid cost less than flex - but they have thinned out the flex more and more over the years, and now it is 1/4 to 1/4 as thick as the rigid. A combination of flex and rigid is often a good choice if you need flex through the damper area (fireplace)....

My suggestion is to spend a little more if you are going to be in the house for a long time. For instance, if the vendor offers two thicknesses, go for the thicker (with flex). There are also some premium processes...most flex is simply pressed together, while some (ventinox?) is welded...obvious a difference if true.

Very typical for folks to over-spend on the stove and then try to get away cheap on the stack....but think about it, that is like spending big on the engine, and going cheap on the tires!

I suppose I am shoveling chit against the tide, cause it seems everyone wants the $300 aluminum foil thickness liners.

Now I hate to say it but I have seen the difference in crimped pipe and welded.. and to tell you the truth each if not made correctly will fall apart.. In england they make their pipe in 3-500 foot sections throw it on a truck and follow the sweeps around to each job cutting off what they need... I have seen 300 ft of welded pipe fall apart because it wasn't welded correctly... It all comes down to who's running the machine that makes the pipe and the surrounding management that has setup checks and balances to make sure that the pipe they are making is strong. And as always stuff does happen... We had two 8 inch flexible pipes break out in the field the other day... these kinds of things do happen a couple of times each year... the difference in manufacture's and also dealer is how quickly are they replaced... For example I get a call like that from a dealer, and the liner is going out the same day as long as it isn't an odd size like 9-10-12... Hope all of this helps clear up some confusion.

 

[eba1225]

I have a flexible liner, would say it is the non-smooth interior. Ran a 6" liner in a 8x12 flue. Thought I could get a layer of insulation around it and run it up the flue, wrong answer, I needed the 2" to get the liner to move in the flue because the flue was not perfectly smooth, cement at the joints of the flue liner. Other than getting the liner up the flue it was pretty painless and works really well with my Lopi.

There were times during the installation that I thought I was sc%^#ed because the liner would not move. I took a break, had a drink thought about it for a couple minutes and went back at it. It moved once a little more elbow grease was applied. One thing that I did notice is that the flexible liners can take a lot of abuse, at least I think so.

By doing it myself I figure I save 300-400 on installation of the liner and stove. Once the liner was installed (ttl of 8 hrs - some on the roof, some designing pullers, some taking breaks, and most on my back pushing the liner up the chimney) the rest of the installation was a walk in the park, maybe 1 hour.

My suggestion is if you are unsure of your ability to do the job get someone to do it for you.

 

[jbrown56]

Thanks to all for your thoughts. wll 6" rigid fit my 8 x 10 flue and after the tail piece of the tee is on the liner how do you assemble the thimble end of the tee once it is in the flue

Jim

 

[elkimmeg]

The kit I used from magnaflex included the tee and a connector end as well as the flue cover and chimney termination cap

 

[jbrown56]

First, I would like to thank everyone for your input on this subject.Yesterday was my lucky day because my brother in-law called. He has been a pipe fitter for 25 years and is an excelent craftsman. He will fabricate and install the liner for me whch will be rigid ss pipe because it is a straight flue. I will get my Oslo in a couple of weeks and maybe it will be cold enough to burn by then.

 

[Gooserider]

First, I would like to thank everyone for your input on this subject.Yesterday was my lucky day because my brother in-law called. He has been a pipe fitter for 25 years and is an excelent craftsman. He will fabricate and install the liner for me whch will be rigid ss pipe because it is a straight flue. I will get my Oslo in a couple of weeks and maybe it will be cold enough to burn by then.

What will your brother be using for pipe? Not questioning his expertise, but you do want to use a "listed" pipe for the application - otherwise you may have problems with insurance, permits, and other gov't paperwork as they won't like something that isn't a UL-Listed and approved product, no matter how good whatever the alternative was.

Gooserider