Chimney Liners???

[Jason762]

I am researching chimney liners and have a few questions. I am looking to possibly vent an Osburn 2400 insert that is in an exisiting masonry fireplace. I have seen many different ways to vent. I plan to do a full re-line of the chimney. The problem is around my damper/smoke shelf there is only about 5 1/2 inches of space, not enough room for a 6" pipe. I was told by one salesman that I could "oval-out" the flex pipe to make it fit. Is it that easy or is he just trying to make a sale? He said its pliable enough to just step on it or bend it by hand to make it fit. Also I have seen on some websites, they recommend using solid 6" pipe to a section of insulated oval flex pipe that is 4 1/2" in diameter so it fits around the smoke shelf. This method is a bit more expensive. Now is it better to go this route or is it better to go with all flex? I've seen many sites that say all flex is fine. Does the flex need to be insulated? Also some flex is very inexpensive, I've seen some on e-bay for $300 for 25' of 6" flex, while other sites have that amount for hundreds more. I know usually you get what you pay for, but at the same time I don't want to spend money unnecesarilly. Basically I'm looking for someone with an unbiased opinion (no alterior motives) to give me a little schooling in venting 101. Thanks for the help.

 

[Sundeep Arole]

I had the exact same issue with my case. I did not want to ovalize the liner - which is not really good for draft. What I had to do is cut out a section of the damper frame so the pipe could go through. My damper frame made out of cast iron. I tried the cut initially with a sawzall and a carbide grit blade - that was a hard job. In the end I got help from another member on this forum and he bought over a angle grinder with a metal cutoff wheel, which did the trick. No need to ovalize if you can do that.

 

[elkimmeg]

there are many ways to accomplish the full liner the best way is to keep the full 6"
Aceptqable is to ovalize it enough to fit threw the damper or use all oval liner
Remember ovalization creates friction and draft resistance. Also condusive to cresote build
up at the point of resistance. Hopt flame cut out enough damper area so he would avoid this prediciment
what is required by code is TH 2100 316 stainless steel.

A lesser grade stainless steel 304 can be used but listed for use with an insulation blanket.
Your manual should indicate what liner has been tested with your stove and speced.
To insulate or not. Insulated liners draft better. The better you draft the more effecient your stove will opperate
Another factor is your chimney location. An all interior chimney may not need insulation. An esposed chimney,
I suggest you insulate. In any case the manufactures specs of the liner must be followed to pass inspections and codes If you liner is listed to be installed with insulation there is no alternative but to insulate. Some manufactures only require insulation for liners in exposed Chimneys.

What you have to do is review your stove's specs and also download the liner manufactures specs after you fully understand what is required then match the setup tha makes money and preformance sense

 

[joshuaviktor]

Ok, here you go. 316Ti is 316Ti, wherever you get it. That is a stainless steel alloy, BTW. IF you can get a name brand on Ebay, get it. Realize that your local store might not be interested in helping you fix things, if you screw it up, as after all, you didn't buy it from them. Paying more for a little advice and help from experts is a great thing, if you can afford it.

If you can't, like me, then do it yourself. I recommend doing some serious reading on this forum, and googling the heck out of it BEFORE you attempt the install.

As for insulation, it depends. It depends on the chimney you are putting it up, the draft, the expense, etc.

Do some reading, and good luck

 

[Jason762]

The masonry chimney it will be going into is an exterior chimney on an outside wall, so it is exposed on three sides. From what I've read it seems the best way to go about this is to spend a little extra $$$ and use double wall, rigid 6" pipe for the majority of the run, then use a double wall, round to oval section of 6" flex, wrapped in insulation, to get around the smoke shelf and onto the unit. Sound good??? Runs around $600 for 15 foot total.

 

[Sundeep Arole]

Or you can use a 6" lflex liner all the way to the top wrapped in 1/2" insulation. About the same money. How big is your existing flue tile opening? A 6" liner wrapped with 1/2 inch insulation will need around 8 inch openning in all dimensions to pose minimum install troubles. If you only have 15' of chimney and a roof that is relatively easy to climb and stand on, you might just be able to do your own install. The lightweight 316Ti liners of that length are light enough that you can do the install unassisted. I wouldn't recommend doing it in the winter, though, unless you know exactly what you are doing.

 

[Mike Wilson]

I paid to have it installed, and learned that it was actually MUCH easier than I thought. We did a neighbor's house with 22' of 316Ti 6" flex which he bought brand new on ebay for a whopping 300 bucks. Came with the seal off plate and cap, etc. We did his entire installation in under two hours. The flex was ovalized, by us, to fit through the flue. The ovalizing closed it down to 5.5 inches, no less, so it was a minimal issue. His insert drafts very well, and he has had no problems with the sytstem. Plus, he has an extra 600 bucks in his pocket, compared to what I paid for the same thing.

Also, both our installations are on external chimneys, and are not insulated. We both justified it this way: The top of the chimney is sealed off with a plate. There is also another damper plate on the bottom. Therefore, some (yeah, not all, just some) of the heat from the flue heats up the air space between the liner and the clay chimney tile. This warm air acts like (yeah, not as good as, but like) insulation. Seeing as the warm air cannot just flow out, the extra heat helps the draft.

YMMV... but that's mine.

-- Mike

(currently thinking of switching to the "dark" side and getting a Harman Stoker ;-) )

PS - Wife was complaining this WINDY (45 knots!) afternoon... saying "it's too hot in here" ... I thought to myself "Ha! Take that! after you always complaining you are too cold!" ... then I threw 3 more splits in the Jotul. 76 degrees in here... mmmmmm.....


PPS - who's the clown who just reviewed a Ryobi stove in the stove review section!
Ryobi's makin' stoves ?!?!

 

[ethcad]

I think there must be some difference in the thickness of the various stainless steel liners on the market. Mine was the 6 inch Homesaver ultra pro 316ti. It was far too stiff to "ovalize" just by stepping on it or squeezing it. I tried clamping it with heavy duty bar clamps every foot or so and could only squeeze it down a 1/4 inch, if that. Finally used my 20 ton logsplitter to squeeze the liner between 2x4s.

I had to ovalize to get down the 6 inch wide flue tile. At the damper, I used an air angle grinder with cut-off wheel and cut out a chunk of the damper - very easy, only took 15 minutes.

My chimney is interior approximately 20 feet high. Liner is uninsulated. Draft is superb with Hampton wood fireplace insert. I'm in No. VA so not too cold generally. Used a sheet metal block off plate at the damper.

 

[Mike Wilson]

I ovalized it with 2 pieces of 2x12 and 2 giant C clamps that I got from the machine shop. Took 20 minutes, and worked like a charm.

-- Mike