Pre insulated liner

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tjcole50

Minister of Fire
Oct 5, 2013
509
Ohio
So I read recently you can't ovalize pre insulated liner. It was a post on here somewhere through the search. I do plan to cut a larger opening through damper because currently I have about a 4.5 inch gap. If it is true would it be wise to just buy like 5-10 ft of uninsulated liner and couple it to the pre insulated for fitting on top of stove? Last question is the deluxe terra cotta top plate worth the extra money? On a budget here
 
i would just remove a section of the damper and masonry if needed to allow it to go through without altering the pipe .When i install liners i leave about a foot or so unisulated where it hooks onto the insert.As far as the top plate i wouldnt waste any extra money on it, stainless is all you need
 
My damper has opening of 4.5 inch which I will cut to larger opening but there isn't much to trim so still going to be tight which is why I'm think I will have to smash a little... Is the pre insulated stuff insulated the full length or are end section just regular ss flex?
 
the ends of the liner will have a little flex thats uninsulated .Like i mentioned earlier you may need to remove a little masonry .Dont be afraid of taking a couple bricks out of the smoke shelf lip to get the liner through there, i have done it hundreds of times.
 
If your talking about pre-insualted rigid liner, just get a 5' section of flex for the bottom to go from the old lower clay flue area through the smoke shelf and onto the stove outlet, and the rigid will connect to the flex and run the rest of the way up. This is what I did and it works very well, and made for an easier install. You will still need to cut the damper out a bit. Cut the damper out oversized for some added maneuverability.
If your running flex, with insulation wrap, just cut or leave the last few feet of insulation off, at the smoke shelf down to the insert. Plan on a block off plat at the damper area. You can also cut the insulation to end just at the top of the block off plate.
 
If your talking about pre-insualted rigid liner, just get a 5' section of flex for the bottom to go from the old lower clay flue area through the smoke shelf and onto the stove outlet, and the rigid will connect to the flex and run the rest of the way up. This is what I did and it works very well, and made for an easier install. You will still need to cut the damper out a bit. Cut the damper out oversized for some added maneuverability.
If your running flex, with insulation wrap, just cut or leave the last few feet of insulation off, at the smoke shelf down to the insert. Plan on a block off plat at the damper area. You can also cut the insulation to end just at the top of the block off plate.
Yea I plan on running bottom 5-7 foot just bare ss flex to top of stove. I'm going full flex liner just didn't know if the pre insulated stuff had some kind of adhesive holding the insulation on the liner that would prevent me from making clean cuts. Let's say I buy 20ft on pre insulated liner and a 5-10 ft section of plain ss liner for top of stove, is there a coupler adapter to use to join those sections? My damper also seems beefed up compared to some pics I have seen , toward the face of fireplace the frame seems very thick with only a minor lip that I can trim and the putter damper frame is not much more. I'm also planning to stuff as much roxul up there as I can . Do you stuff that insulation clear up to where the clay flue meets the masonry brick? Once again thanks for advice! I'd like to do it once and do it right!

Any opinion on magnaflex liners? Was contacted by a rep but correct me if I am wrong but I see pre insulated as being cheaper,faster, and easier than buying the insulation kits and wrapping myself
 
If your running full flex. There is no coupler needed in the run. Where are you getting flex liner already insulated? Not sure that is even offered from what I have seen and worked with. The insulation is usually separate, and you have to slide it over the liner before you install the liner. Usually has a s.s. mesh wire than slides over the insulation that holds the insulation around the s.s. flex. You can just insulate down to wherever you want, then leave the rest bare. No sense ordering two pcs of liner. Order a few feet more than you thing you need, then trim the excess off the top after you get it in place and installed.
I had to use both a sawzall and angle grinder to cut the steel out of my damper area to allow the liner to come down through and connect to the insert.
I suggest making a metal block off plate at the damper are to close the hole off around the liner. I had no room to work, so I had to install my block off plate lower, just above the lintel.
I reused some rockwool that was on the old slammer install block off plate, which I laid on top of the new block off plate.
Some here just stuff Roxul up there, I am preferential to a block off plate. With a blower going, I don't want to deal with any fibers coming off the Roxul and being blown into the house air for me to breath in.
If you elect to use the Roxul, all you really need is enough to close up the gap around the liner at the hole the liner is coming through as the damper area. You can stuff as far as you want up, but not really needed. I don;t have any insulation around the bottom 5' of liner as I want the masonry to absorb the heat which it will gather and release at the end of the burn. I also get the benefit of the backside of the masonry at the back of the fireplace to transfer some heat to the new bedroom in my addition which is on the backside of the fireplace. Nothing major, but it does transfer a little heat.

Do you have a link for the "pre-insulated flex" your are thinking about? I don't honestly know of any company that sells flex pre-insulated?
Magnaflex used to be a member on here, not sure if he still is. Of what I read from other members that bought & used it, it is a good product.
Not sure on the cost, and if more, whether it is worth any added cost of not.
 
I'm for sure going to do block off plate and but do u stuff roxul up above the damper frame? Or just above block off plate? The magnaflex rep said it was called insulflex haven't looked into it much but thought it was pre insulated flex . I am ordering 5 ft extra for sure

Edit
https://www.hearth.com/talk/threads/insulflex-pre-insulated-liner-installed-today.45396/
Original poster used pre insulated


Roxul goes on top of the block off plate, which may even be at the damper frame, depends on where you set the block off plate.
 
Ah, this is a two layer flex with the insulation between. Looks expensive. you can run it all the way to the insert though it appears. And prolly not have to remove the outer shell or insulation at all.
You may also want to compare the cost, VS double wall rigid liner, which is rigid with insulation between the walls also. If the price is the same, the double wall rigid is better in my opinion. You would merely need a 5' or so pc of flex at the bottom to go from the first clay flue to the insert. The rigid mates to the flex and no coupler needed.
Either will do the job. The rigid is easier to clean and more durable.
Just dome food for thought. Either liner system with do a great job.
 
I started out with small 4 inch damper frame and cut it out and chipped some fire brick out to allow 8 inch insulated liner in there

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Do you have a link for the "pre-insulated flex" your are thinking about? I don't honestly know of any company that sells flex pre-insulated?
Magnaflex used to be a member on here, not sure if he still is. Of what I read from other members that bought & used it, it is a good product.
Not sure on the cost, and if more, whether it is worth any added cost of not.
http://stores.ebay.com/theheatelement

TJ, if you want 25' Insulflex with the last 5' uninsulated, you can probably order it that way. . .just tell Rainer what you're doing.

The top plate for a terracotta flue is the same; it just has a lip on the stainless plate to hang down around a terracotta flue tile that projects above the chimney crown cement. I like it. You're supposed to seal the top plate and the flue tile with silicone anyhow, but I feel like the lip helps to keep weather away from the seal.
 
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Excavator excellent angle showing damper frame. Looks like you did a small block plate just covering existing 4" gap. Is that any less effective than a full block off plate like the ones that fill the entire fireplace cavity at lintel level? As for flex liner I'll prob keep it simple and just get some basic flex king with insulation kit. Are eBay vendors trust worthy ? Haven't used evil bay for anything in awhile. Have not seen anything really stating 1 or 2 ply or the more expensive smooth wall liners are better. I'm sure they are but if the basic flex liners do their job just as well than that is good enough for me

Starting to get tired working this overtime at work and researching to do this. Hope this nc-30 throws the heat !
 
No way to say other then the block off plate I fabbed up keeps the heat down in the house and not up the chimney. It works great
 
Do you have a link for the "pre-insulated flex" your are thinking about? I don't honestly know of any company that sells flex pre-insulated? Magnaflex used to be a member on here, not sure if he still is. Of what I read from other members that bought & used it, it is a good product. Not sure on the cost, and if more, whether it is worth any added cost of not.
http://www.northlineexpress.com/med...08d6e5fb8d27136e95/5/m/5mg-06ifdcs035-xlg.jpg
The Magnaflex rep is still here. Surprised he hasn't chimed in yet. I just purchased a 6" x 20' insert kit from them this fall. Ranier was good to work with, and I was pleased with the quality of their product. I know of at least 1, possibly 2 others that have just recently used Insulflex on their installs and were happy with it. The price was no more than a plain single ply liner kit, it's an excellent value for what you get! I thought that the fact that they were willing to custom cut various parts of the kit for no extra charge was a nice added touch. He also threw in some extra insulation to seal around the liner where is passes through the old damper too, nice! Magnaflex...recommended! ==c
 
TJ

The Insulflex liner can easily be modified to have the end not be insulated. The outer jacket can easily be cut with tin snips and the insulation removed from the last few feet.

Having just recently installed an insulflex liner, I would have to say this is the way to go - a much cleaner and easier install that a liner with the insulation wrap kit, which is what I used before I found this pre-insulated liner. I also had to do some cutting to fit it through, but once I had the angle grinder going, it was not an issue. The insulflex manufacturer was great to work with and I am sure would be willing to work with you on any special installation requirements you might have.

One thing that I have experienced with my SS liner with the wrap kit is something you may want to consider before ovalizing. A chimney brush may not fit through the liner too easily. Top down chimney cleaning should not be too much of an issue, but my first time cleaning I tried pulling the brush up from the bottom and it was very tight trying to get through the ovalized section.

Good luck with your install!
 
tj, yes if you can put the block off at the original opening, that is the best way to go. Easier and less material and work if you can reach up there and work it.
It really is no less effective. The goal is to keep the heat from migrating upward and transferring out along the length of the masonry above.
I think many have used Rockford on Ebay for their liner purchases, and are happy with them.
Magnaflex has also had a few happy customers on as you heard back from at least one.

One other place to check out is Chimney liner depot.
You can buy a kit from them for a damn good price.
You can also get an entire kit, modify it with whatever parts you want, and get it with a cleaning kit, caulk etc, just about everything you need with the exception of the block off plate, for a few hundred dollars less for everything, than most other suppliers. Just do your research, and pick the supplier you feel best meets your needs & cost.

Like to Chimneylinerdepot: www.chimneylinerdepot.com
 
x2 on chimneylinerdepot
 
Thankyou all for your opinions. Lot of options , think I'm gonna go the liner depot route basic liner 30ft and cut insulation off for last 10 ft and probably will do the smaller block off at the damper instead of full size sheet above lintel ! I will for sure posts pics of install in the next two weeks. Hopefully no snags as this is my only source of heat right now!
 
tj what i did was make 2 steel brackets that just hang above damper frame and each have 1 hole. Then i used large toggle bolts that hold the block off plate and liner depot offers a blanket of high temp insulation to fill in gaps. That is the white stuff in my pics around liner too create tight seal
 
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tj what i did was make 2 steel brackets that just hang above damper frame and each have 1 hole. Then i used large toggle bolts that hold the block off plate and liner depot offers a blanket of high temp insulation to fill in gaps. That is the white stuff in my pics around liner too create tight seal
Prob attempt the same thing did you place an roxul up farther into chamber or just a small later above plate. And the smaller block off seems easier to work with
 
Prob attempt the same thing did you place an roxul up farther into chamber or just a small later above plate. And the smaller block off seems easier to work with
just small amount arounf liner to make everything nice and tight. I used fire board that Lowes sold in a sheet of 3x3 ft and I just cut it to work
 
Never looked into anything but sheet metal I'll look into fire board ! Be nice to make the block off support itself with a T on damper frame and have 2 pieces being held up by 2 wing nuts if you know what I mean. They just kinda float there and if need be unscrew wing nuts to drop them
 
Never looked into anything but sheet metal I'll look into fire board ! Be nice to make the block off support itself with a T on damper frame and have 2 pieces being held up by 2 wing nuts if you know what I mean. They just kinda float there and if need be unscrew wing nuts to drop them
We never stop thinking and modding lol
 
Well another question here. In the pic is it possible or safe where the thinner section of the damper frame. Can I take my grinder and score a couple bricks with a line parrellel with damper and chisel them out? I think that would give me a near straight shot down! But I want to make sure structure wise that it is safeimage.jpg
Guess best way to describe is the top part of damper frame as in pic which is actually the exterior side and the larger metal is toward the living room. Ha if that helps but I figure knocking two bricks down where I will be cutting would garuntee zero ovalizing and also allow less bend and I could tuck the 30 farther back in fireplace. May make block off plate a bit different tho...
Also is stove cement reall necessary at all connections? Figured hose clamp on appliance adapter and a screw where connecting to stove collar would be plenty?
 
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