Need to install a liner, opinions on brands & advice wanted.

[HaTaX]

I've got an old 80's insert that's installed slammer style currently, and I'd like to get away from that setup within the next 2-3 weeks by going with a full liner inside my existing terracotta flue.

Flue size is 11 5/16" x 6 5/8" ID that goes down about 15' to the smoke chamber, from there it's about another 5-7' feet to the insert itself. The damper plate is 6" x 24" and I plan on making a block off plate, notching it just a little for the liner and stuffing the smoke chamber with Roxul. Roxul would also be used for the top and bottom insulation in the existing flue and any extra I have I just might push down further in the flue to help with insulation.

That brings up a question, it's a ~20' length chimney that sits on the outside wall of the house, but the garage is enclosing the lower ~12' of it. Draft has never been a problem with my current setup and I'm not sure if it's worth the cost of buying a liner insulation wrap.

I've been looking at the Flex King PRO 6" x 25' for ~$500 and the Homesaver Ultra Pro for ~$420. Does anyone have any opinions or experience with those liners? I like the fact that both of those allow for the warranty to be honored if installed by the homeowner, and that's why I had focused in on those two.

I think the chimney is in pretty decent shape, and if anyone wants to take a peek at some pictures of what it looked like after a light cleaning, they're a few posts down in this thread: https://www.hearth.com/talk/threads...ve-slammer-install-looking-for-advice.103780/

Thanks in advance for any advice you've got for me!

 

[BucksCounty]

I have installed 4 in the past couple years (2 for me, 1 for parents and 1 for a buddy). I have purchased from chimney liner depot for all.

Only 1 is a completely exterieor chimney. It is a 20ft in my house. I didn't insulate. I clean twice a year and burn from mid october to marchish. Never a real issue or a tremendous amount of creosote. Burn dry wood and it should be good. feel as though the cap, clay chimney liner around the flex liner keeps a blanket of warm air.

I used the flex king pro on 3 and regular liner on 1. The flex king pro is a little more challenging to get down the chimney....get the pull cone. I might even recommend a 5.5in. your exsisting chimney liner is the same size as 3 I put in....gets challenging sometimes and had to ovalize a little. You will need to cut your lintel. 4.5in. grinder.

I roxuled all and did block off plates on both my stoves. very easy. Rest the sheet metal on the lintel and cut around. https://www.hearth.com/talk/threads/f600-jotul-install-and-breakin-fire.72538/#post-915896

Good luck.

 

[chimneylinerjames]

I would also recommend using the 5.5" liner. The OD of the liners are 1/4" than what is stated, the 5.5" is the ID so the outside would be 5.75". That would leave you enough room to play with. Especially if you go with the Flex King Pro, that is a smooth inner wall liner, so that would increase your draft and offset any difference there would be with using a slightly smaller liner, most likely you would have better draft with the 5.5 Pro than a regular 6".

 

[begreen]

I'm leary of choking this down even further. That's not a long run of liner. The stove looks like it's already been reduced down from 8". Are you planning on insulating the liner?

 

[chimneylinerjames]

The stove looks like it's already been reduced down from 8"

That is a good point, I doubt a stove that old is 6". You shouldnt reduce the liner that much, use an 8" liner and make it oval. Its alot more money but its the right thing to do.

 

[HaTaX]

Yup the current slammer installed stove has an 8" outlet on the top, I'll be reducing that down to 6" in anticipation of getting a new stove. I think the 8" outlet on it is a little overzealous anyway, the two adjustable dampers on the side are 2 3/4" in diameter with a 3/4" sized metal bar in the middle for the bolt to run through. With the cross section of my air input, I'm thinking that reducing to 6" shouldn't cause too much of an issue.

FlexKing Pro lists the OD as being 1/4" more then the ID, that should leave me with 3/8" clearance side to size. Yeah, not very much at all, but the chimney is a straight shot down to the smoke shelf and the tiles look like they were laid in there well without any huge gaps or offset in the seams. With that little clearance I can't get an insulation wrap on there, so that's why I was thinking Roxul as insulation on the two sides where I've got some space. Current draft on the stove with the 6" reducer sitting on top is just fine, I just threw it on there to see if it really murdered my draft and honestly I haven't noticed a change at all.

So this stove doesn't have more then this heating season left in it's location, I'd rather get a stove on a deal this summer and have some fun with my secondary mods for a few months. My thoughts are that having a 6" liner and reducing the output is better then leaving it slammer style for any longer, but maybe my thinking there is wrong? It has been running like this for 30 years with no ill effects yet, just a PITA to keep clean...

 

[HaTaX]

chimneylinerjames you got me thinking with the oval liner, it would allow me to insulate my liner with a wrap kit easily and also come through the damper plate with no modifications to it whatsoever. Both big pluses in my mind, the only real downside is component cost. Pricing them out from Rockford Chimney Supply I come up with $540 for a 6" round kit with a nice terracotta top plate ($675 for the smooth wall version, same specs), and $1090 for 24 feet of the 5" x 8.15" oval liner with the needed accessories. I noticed the oval liner has about $370 of needed components while the round ones only have a $90 charge for the nice terracotta top, and that nice top isn't an option on the oval kit. Top plate isn't that important, but the cost of the adapters kind of stinks. I'll have to pick up a new brush anyway, so I guess a little more $$ for an oval brush doesn't bother me.

Is it worth it to go the oval route for twice the $$? I'd probably get an insulation wrap kit for the oval liner since I'd have over 1" of space available in the narrowest section of the flue, and with the round liners I'd most likely stuff Roxul in lieu of wrapping it and not having it fit...

 

[chimneylinerjames]

Well if you are thinking of getting a new stove this summer, I would prolly just get the 6" liner. That way you save some money now to put towards the cost of a new stove. In the long run i think that is better, a more efficient stove with a round chimney liner. You would be impressed on how much less wood you will burn but get the same or even more heat output with a new stove.

But yes oval liners are not cheap, one reason is shipping them also, they have to be shipped as a straight piece. So use the 6" for now and hook up the new stove to the liner later.

 

[HaTaX]

Thanks for the advice James! I was kind of wrestling with the question of the oval liner being the 'right' way to do it and if it was beneficial to have the round shape vs the oval. Makes sense to me that a circular path is better for the smoke to travel in, and that's probably why pretty much every stove today has a round outlet.

So up on the roof today again to get some measurements, and here's what I came up with. It's ~19' 8" from the top of the chimney to the damper plate, and probably another foot is needed to reach the outlet of the stove. Think it's better to go with a 25' liner to make sure I have enough to reach the outlet or just get a 20' and go with a small section of rigid or adapter down on the stove side? I know the appliance adapter will give me another 6" or so and that might just be enough to make a 20' work, but adding another 5' of flex liner wouldn't be the end of the world either they're just more expensive depending on the brand. (Some are $50 more, others are $120 more for the extra 5')

 

[HaTaX]

I'll just pick your brain on one more thing James if that's okay. I'm assuming that you work for chimneylinerdepot.com and I've pretty much narrowed it down to your Flex King PRO liner and one other, although I will most likely go with the Flex King PRO after looking into a few things today.

Question, I noticed in the FAQs that insulation is required to meet UL specs. I'd rather not insulate the liner with a wrap as it won't fit down the existing flue then, but my terracotta tiles are all in very good shape. My plan was to stuff some Roxul down the flue with the liner so I'm providing a little bit of insulation as well as blocking the passage of air off. Since I'll be leaving the clay liner in place, would it meet UL specifications if I installed it as described?

 

[chimneylinerjames]

If you know your flues are in perfect shape with no cracks you will be ok. If you have any cracks it is required to have insulation.

But the insulation isnt just for safety, it is for performance reasons also. If you read around on this forum about the difference once insulation is installed you will see it makes a huge improvement. Especially in cold starts and long burns when the flame is dying down.

 

[HaTaX]

The 3rd tile from the top has a small crack in it, otherwise all the other tiles are in good shape. This tile would be in the upper exposed section of the chimney, and I've heard from a few chimney people around my area that it isn't much to worry about if it's near the top and there's only the one. I'll attach a picture here of the flue just to give a better idea.

I've been considering putting some Thermix down with the liner instead of packing it with Roxul, think that would be a better route long term? I'd like to retain the ability to turn it back into a open fireplace if desired in the future, and even though they say it's removable, I'd worry about how easy the removal would be... Does the stuff bust up easy enough with a screwdriver and a hammer once cured?

 

[BrotherBart]

All sounds good. After you get that glaze out of that flue. A hot liner is gonna set that stuff off. And at that point it will be contained in a closed space between the block off plate and the top plate.

Don't think I know what I am talking about? This was my flue before I set it off.

 

[HaTaX]

Yup! Should have mentioned that I know those tiles are nicely glazed and need a cleaning... The entire chimney will get brushed and sprayed from top to bottom before the liner goes in. Those pictures are from a week ago and I have run some creosote remover through the stove to make that stuff a little more manageable.

For what it's worth, the smoke chamber and such are pretty well cleaned, I had done them right after I took that shot of the flue. Knew I would be taking it all apart to clean again, so I didn't scrub the flue tiles at that time.

 

[chimneylinerjames]

Does the stuff bust up easy enough with a screwdriver and a hammer once cured?

It does not harden like concrete, it does break up fairly easy. One thing I have done is block off the bottom good, pour the first bit of the insulation down wet. Then after that just pour the rest down dry, it is dusty, but it will be fine. So if you really wanted to remove the liner later easily, you could just take out the bottom section of the cured insulation and the rest will fall out. It wont be fun to do, lots and lots of dust but it is one way of doing things.

The pour down insulation doesnt get mixed with lots of water, you just mix it so it is damp, not like mortar at all. So it wont be hard like concrete.

 

[HaTaX]

Good deal, I'll be thinking about insulating it now, and with only 3/8" extra space I think that the thermix is my only option if I don't want to remove the clay tiles. Honestly if I need to pull them it probably won't be a big deal, I can just weld a nut to a small thick metal plate that will fit on the end of my existing cleaning brush rods, and I've got myself a tool that I've seen used in a few youtube videos.

One last thing I'm wrestling with is, is the Flex King PRO Max worth the extra $$? There's little information on the site as to why the Max is better besides saying that it is a heavy duty liner, no specifications on the thickness, seam type, etc. Just wondering what the real differences are there as there's about a 30% increase in cost for the Max system, so I'd assume it's more then just superficial / marketing differences.

 

[chimneylinerjames]

The Pro Max is our newest liner system, we are working as we speak on writing more and more info on the liner. Let me explain the basic differences. The Pro is a 2 ply liner, this means it has 2 layers throughout the entire length of the liner. The inner layer makes the liner perfectly smooth. It is 2 layers of .005" metal.

The Pro Max is a 1 ply liner, .010 inch stainless steel strip. So it is twice as thick metal that is used but same overall thickness. it also has a smooth inner wall. So with the thicker metal used, it can take a beating. The 2 ply liners tend to be a little sensitive under tough conditions when installing. For example, if you are hooking a rope to the end and just pulling that rope around a sharp edge inside the chimney, there is a decent chance that inside layer will be effected. But with this liner being 1 ply, it may dent but that is it. It also can take a much more aggressive cleaning than the standard liners.