Question on venting wood stove up a brick chimney

[Southron]

Hi all. Just joined the forum as I've been reading and reading and can't seem to make up my mind here or get a specific answer to my dilemma(s).

I've got a brick chimney in a ranch house (with attic). It's probably 50 years old. The former owner had an old-school cast iron insert in the fireplace venting directly up the chimney. I have removed the insert and would like to place a wood stove on the hearth and vent it up the chimney. Budget is an issue so I'm wondering if I can just run stove pipe up the chimney all the way to the top. I can't seem to find anything that addresses this question specifically, though I've read a lot suggesting I run insulated steel pipe all the way up. The difference in price, of course, is roughly $7 per 24" section of stovepipe vs roughly $100 per 36" section of steel insulated pipe.

Of course I understand why one needs to run insulated pipe up through ceilings, attics, walls, etc. But if the pipe is going to be inside a brick masonry chimney, why isn't regular black stovepipe sufficient?

The chimney itself is in decent condition, though I was given the usual ridiculous $2000+ quote on relining the entire chimney with SS liner. I just don't have that kind of money.

If the stovepipe is insulated from combustibles by the brick, why is this a problem?

Thanks in advance for your responses. I don't want to set something up that's unsafe, but I also can't afford to spend thousands of dollars.

 

[Slow1]

Have you evaluated just dropping a flexible liner down that chimney? I haven't done it but there are others here who have done so and saved on the labor etc.

I'd probably have a certified sweep do a complete cleaning and inspection first though to be sure your flue is safe.

 

[PLAYS WITH FIRE]

If it a normal, good shape(inspected) terracotta lined chimney you can use a flexible stainless steel liner with insulation wrap. Those can be had for, depending on length, 550 bux from chimney liner depot. The insulation helps with draft and for fire protection. A warmer chimney produces better draft and helps by not having cold spots for creosote to form.


Stove pipe, and I will be corrected if wrong, may not be stainless and will rust and just not safe for chimney fire conditions. Stainless double wall would be overkill and much more expensive than flexible liner with insulation wrap.

And not to mention putting double wall down a chimney can be a real pain!

I would post some pics and dimensions of your stack. Inside of the damper area and such...

 

[mellow]

Black stove pipe (singlewall) can not be used in a chimney, single wall can be used on a free standing stove because you see it and can notice an issue, you can't do that within a chimney.

Stainless Steel is Required for chimney installs because it is stronger and can hold up to more abuse than singlewall black stove pipe.

Black stove pipe is a wear and tear kind of item, some have to replace it every other year, where as a stainless steel liner can last for 10+ years if taken care of.

 

[Crane Stoves]

Dear lord do i even try to teach about the nationwide conspiracy regarding stainless steel liners into chimney's with perfectly viable terra cotta liners ....

The first question that needs to be asked... is your chimney lined currently? whats it lined with? whats the condition of the liner?

If you indeed have a terra cotta liner and its all in good shape... you can use black pipe (i would try to get it passed the "shelf" so it gets into the liner itself), i like using 1/2"rock board for blocker plate but most folks here i assume would have sheet metal cut for it.

 

[mellow]

Single wall pipe can not resist corrosion from creosote and after a chimney fire it should be replaced. It really is no comparison to stainless steel.

Must be a full moon outside.

 

[branchburner]

If you indeed have a terra cotta liner and its all in good shape... you can use black pipe (i would try to get it passed the "shelf" so it gets into the liner itself), i like using 1/2"rock board for blocker plate but most folks here i assume would have sheet metal cut for it.

If you did NOT get it past the "shelf" so it gets into the liner itself, you would be violating code. A direct-connect MUST pass the bottom of the first tile.

Even so doing, it is worth advising the OP that a short run of black pipe here may only last a few years (and is not recommended above the block-off), while SS may last a few decades. Also worth mentioning that the direct-connect may be a creosote factory, depending on other factors (flue size, interior/exterior flue, quality of wood burned, burning technique, etc.), that might require removal of the stove and blockoff for annual cleaning.

To the OP: the stovepipe is insulated from combustibles by the liner WITHIN the brick chimney, not the brick itself, which may not contain a chimney fire. That liner could be clay tile, SS, or both (or an approved castable material), depending both on the condition and size of the existing flue.

 

[Charles1981]

Is the chimney interior in the house or exterior? If you have a interior chimney I wouldn't even both with the insulation...Just block off the top and bottom with an insulating material and the pipe will heat the air in the chimney very well.

This isn't the case if your chimney is exterior however. My chimney is masonry lined with clay and directly in the middle of my house. I didn't insulate it and it works very well.

 

[branchburner]

If you have a interior chimney I wouldn't even both with the insulation.

Let's first establish that the chimney at least has a clay liner!

 

[fossil]

The first question that needs to be asked... is your chimney lined currently? whats it lined with? whats the condition of the liner?

The second question is what is the cross-sectional area of the existing flue as compared to the cross-sectional area of the appliance flue collar...?
Third question is what's the height of the existing chimney?

Putting a free-standing wood stove on the hearth and venting it up the existing chimney raises a whole host of other questions about fireplace opening dimensions (particularly the height), hearth dimensions, and more.

 

[jharkin]

Black stove pipe (singlewall) can not be used in a chimney, single wall can be used on a free standing stove because you see it and can notice an issue, you can't do that within a chimney.

Stainless Steel is Required for chimney installs because it is stronger and can hold up to more abuse than singlewall black stove pipe.

Black stove pipe is a wear and tear kind of item, some have to replace it every other year, where as a stainless steel liner can last for 10+ years if taken care of.

So I'm 20 years overdue to replace my as liner.....

 

[Crane Stoves]

So I'm 20 years overdue to replace my as liner.....

Im only 10 years overdue so you got me beat!

 

[930dreamer]

WOW, I'm kinda in the same boat here but with installing an insert. So the insulated double/triple lined SS liner goes through non-chimney areas? I can run a flexible/insulated SS liner through my house chimney as long as it's in serviceable condition? This is a great forum.

 

[Southron]

Thanks for all the responses. To answer a few of the questions:

- chimney is in interior of house

- it's TC lined but liner in bad shape. Previous owner had a cast iron stove insert venting directly into the box and chimney -- I'm surprised there wasn't a fire with this configuration.

- chimney is large, approx 24x18 wide

- chimney is approx 22' high

I understand that SS liner (or pipe) is ideal and will last longer. I just don't have the money and want to make it through a winter with warmth, but without burning my house down.

What I haven't seem in all I've read on the issue is what the specific, short-term danger is in running stove pipe up the length of the chimney.

Thanks again. Great forum. Additional Comments and thoughts much appreciated.

 

[930dreamer]

Thanks for all the responses. To answer a few of the questions:

- chimney is in interior of house

- it's TC lined but liner in bad shape. Previous owner had a cast iron stove insert venting directly into the box and chimney -- I'm surprised there wasn't a fire with this configuration.

- chimney is large, approx 24x18 wide

- chimney is approx 22' high

I understand that SS liner (or pipe) is ideal and will last longer. I just don't have the money and want to make it through a winter with warmth, but without burning my house down.

What I haven't seem in all I've read on the issue is what the specific, short-term danger is in running stove pipe up the length of the chimney.

Thanks again. Great forum. Additional Comments and thoughts much appreciated.

It sound like the main issue is that pipe is a wear item that is hidden from view in the chimney.

 

[oldspark]

The liner you need is not 100 dollars for 36 inches, 300 bucks or so I think will cover the cost for the most part.

 

[Southron]

Oldspark- can you post a link to the liner you're referring to? Thank you.

 

[oldspark]

One of many, I am sure others will post also.(broken link removed to http://www.ebay.com/itm/like/250871757864?lpid=82)

 

[Southron]

Oldspark- thanks much. That's much better than the solid SS pipe at $100/3'

So the question remains: is this better than stove pipe simply due to durability or are there other reasons why not to run cheap stove pipe?

 

[oldspark]

This site looks good and might be of some help.

http://www.chimneylinerdepot.com/

 

[elmoleaf]

If I recall correctly, the International Building Code (IBC), which is adopted by many states, references National Fire Prevention Association (NFPA) Code 211, which indicates liner must be corrosion resistant. In short, it is "code" to use stainless.
(Although...if the terra cotta liner is sound and the chimney doesn't have moisture leaking inside, a black stove pipe liner can last a long time...at least 8 years...especially if the long vertical seams and section seams are heavily screwed and everything is well supported....and it gets a good inspection every year when you sweep. Don't ask me how I know this. . )

 

[oldspark]

Oldspark- thanks much. That's much better than the solid SS pipe at $100/3'

So the question remains: is this better than stove pipe simply due to durability or are there other reasons why not to run cheap stove pipe?

Interior chimney, installed with screws, burn correctly and use dry wood, keep an eye on it and inspect it every year, no leaks for water to get in around chimney and I think it could last a long time (having to change stove pipe every other year is just silly). Not sure if you have a code to deal with or not, the stainless is a better product for the application.

 

[Southron]

Thanks all. Oldspark that vendor website is very helpful.

What I'm not seeing, however, is an adapter to get the round pipe (whether it's flex liner or stovepipe up through the rectangular flue. Any suggestions on this?

Guys- I really appreciate it. I've gleaned more from a few days on this forum than from countless hours of googling my questions. Thank you.

 

[PLAYS WITH FIRE]

Cut it with a saws all or angle grinder...most of it did it that who have inserts. Don't mangle so it can be put back if need be, chances are it won't need to be;-) if you cut it no need for an adapter or ovaling, just straight from top to stove.

 

[branchburner]

Many people run black pipe all or part way up a fireplace chimney with no bad results. This is what you want to consider: since your clay liner is in bad shape, and may not offer good protection in the event of a chimney fire, will the black pipe offer that protection if it begins to corrode? (Code and insurance companies say "no".)

For a season or two, black pipe SHOULD suffice, IF you are burning dry wood and not running a creosote factory. Your choice of stove and supply of wood should factor into your decision about how to proceed.

I don't know if you plan on buying brand new pipe, but if you spend $100 on it, so as to only last a season or three, your are still going to want to shell out $400+ for a SS liner down the road given the condition of your clay tiles. You may save in the short run, but in the long run you are simply adding $100 (and more work and worry) to your net outlay.