Suggestions for chimney

[Zombie]

Alright ya'll, can't decide between building a new chimney from block, or going with a prefab. Any advise, insights, or opinions are needed and welcome. The Grandpa bear will be going in the basement, so the chimney will be quite tall, around than 30'. I love the look of a traditional chimney, are there any significant downfalls I should be aware of? I grew up with a Grandma bear as the sole source of heat in my home, and I never had an issue out of our block chimney. I have heard that they are prone to cracking from the heat, how common is this?
The Grandpa wont be my sole source of heat, but will supplement the heat pump on cold nights frequently.

 

[Zombie]

Any insight into building code or rules I should be aware of is also appreciated.

 

[kennyp2339]

A 8" class A chimney would be significantly easier to install, more then likely cheaper that masonry materials and labor, plus it will keep flue gases a little warmer then masonry and easier to keep clean, life expectancy I would say is about the same under normal use, you take care of it, keep it clean w/ no over-fires or chimney fires and its good to go for 20-25 years no problem. You could always build a chase and install stone veneer to give it that classic look.

 

[bholler]

Any insight into building code or rules I should be aware of is also appreciated.

If going with a clay lined masonry chimney you need to maintain proper clearances to combustibles. That means 1" from the outside of the masonry structure to and combustible materials for an external chimney. And 2" for an internal one. But I would never consider building a new chimney with clay liners. I would use insulated stainless. And I would go with 7" if you are set on an old smoke dragon like a grandpa bear.

 

[Zombie]

If going with a clay lined masonry chimney you need to maintain proper clearances to combustibles. That means 1" from the outside of the masonry structure to and combustible materials for an external chimney. And 2" for an internal one. But I would never consider building a new chimney with clay liners. I would use insulated stainless. And I would go with 7" if you are set on an old smoke dragon like a grandpa bear.

7 inch pipe? I was going to go with 8, what are the benefits of stepping down and would it be 8 to the thimble and then step down at the chimney? I ran the Grandma by myself from around 12 years old, dad worked 3rd shift so it was just me there. I never over fired it or had a chimney fire, I did keep the chimney and pipe inside clean though, twice a year in the spring and fall I would get up on the roof and run the Neuman mechanical chimney cleaner we had down it and I cleaned the fire box and pipes ( stove was cleaned more frequently). From reading around on here, I thought stepping down was a no-no and I know that going over will allow the gases expand and cool. If going with the prefab I would build some type of aesthetic enclosure as I don't care for the look of a big steel pipe running up the side of the house. What are the reasons that you would never consider building a new clay lined chimney? I am pretty set on using the Grandpa. I know that newer stoves are more fuel efficient and cleaner, but I just can't shake my love for the old Fishers.

 

[Zombie]

A 8" class A chimney would be significantly easier to install, more then likely cheaper that masonry materials and labor, plus it will keep flue gases a little warmer then masonry and easier to keep clean, life expectancy I would say is about the same under normal use, you take care of it, keep it clean w/ no over-fires or chimney fires and its good to go for 20-25 years no problem. You could always build a chase and install stone veneer to give it that classic look.

20-25 years? That seems to be a short life?

 

[bholler]

7 inch pipe? I was going to go with 8, what are the benefits of stepping down and would it be 8 to the thimble and then step down at the chimney? I ran the Grandma by myself from around 12 years old, dad worked 3rd shift so it was just me there. I never over fired it or had a chimney fire, I did keep the chimney and pipe inside clean though, twice a year in the spring and fall I would get up on the roof and run the Neuman mechanical chimney cleaner we had down it and I cleaned the fire box and pipes ( stove was cleaned more frequently). From reading around on here, I thought stepping down was a no-no and I know that going over will allow the gases expand and cool. If going with the prefab I would build some type of aesthetic enclosure as I don't care for the look of a big steel pipe running up the side of the house. What are the reasons that you would never consider building a new clay lined chimney? I am pretty set on using the Grandpa. I know that newer stoves are more fuel efficient and cleaner, but I just can't shake my love for the old Fishers.

7" liner because 8 is typically to much volume and you need to waste more heat up the stack to stay above the condensation point. And no it would be 7" the whole way. I would never consider a clay lined chimney because they simply do not work nearly as well. They don't hold up as well. They require clearance to combustibles that a chimney won't with an insulated stainless liner. They are harder to maintain than a stainless lined chimney.

 

[bholler]

20-25 years? That seems to be a short life?

Not really. Clay liners life expectancy without any fire is roughly 30 years. And one fire and they are cracked.

 

[stoveliker]

I'd say to get the technically (safety and performance) superior option, and add aesthetics as you wish, rather than getting a lesser chimney because it looks nice.

 

[EatenByLimestone]

I've built masonry chimneys, installed class A, and lined existing ones. I'll never do anything other than class A again if I can help it.

 

[Zombie]

Thank you all for the replies, it is very much appreciated. I am still a novice with this subject even though I grew up with a wood stove. I had knocked down the old shower in the basment, leaving the bottom row of block, and made a concrete pad about 4 1/2' by 4 1/2' and 9" tall. With the stove in the corner, the rear corners of the stove are around 14" from the block wall. No combustibles just concrete block. It is 42" from the tallest point of the stove to the bottom of the floor joists, non insulated subfloor. Too close? If yes, what is your go-to for protection. I want to install it once and do it right, thanks in advance for the advice, I know these questions may be elementary to some of you, this will be my first wood stove as an adult, and a fresh install, so just weighing my options with much more seasoned burners.

 

[St. Coemgen]

I would never consider a clay lined chimney because they simply do not work nearly as well. They don't hold up as well. They require clearance to combustibles that a chimney won't with an insulated stainless liner. They are harder to maintain than a stainless lined chimney.

I installed two new chimneys during renovating our house. One was insulated stainless steel (warranty for 15 years), and the other was am insulated modular prefab clay lined chimney (warranty for 30 years). The distance to combustibles is less for the clay lined chimney. In fact, I can touch any part of the insulated clay chimney above the stove inlet and it is only mildly warm, Upstairs I can even lean against it for a little warmth. The stainless flue is quite a bit hotter; I certainly would not want to touch it for very long. I have found them equally easy to maintain and work equally well. SS was less expensive (but also has the shorter life expectancy).

I agree, that installing a clay lined chimney that is cemented in hard can crack. But my insulated chimney has not cracked in 10 years, and is not going to crack simply from using it since the pipe can expand easily into the insulated layer around it. That is, there are indeed plenty of other ways to install a modern clay lined chimney without worrying about expansion cracking. If such options are available in one's area or not I do not know (I live in Europe where Leier and Schiedel make these types of chimneys), but it is a good idea to shop around in any case.

 

[bholler]

I installed two new chimneys during renovating our house. One was insulated stainless steel (warranty for 15 years), and the other was am insulated modular prefab clay lined chimney (warranty for 30 years). The distance to combustibles is less for the clay lined chimney. In fact, I can touch any part of the insulated clay chimney above the stove inlet and it is only mildly warm, Upstairs I can even lean against it for a little warmth. The stainless flue is quite a bit hotter; I certainly would not want to touch it for very long. I have found them equally easy to maintain and work equally well. SS was less expensive (but also has the shorter life expectancy).

I agree, that installing a clay lined chimney that is cemented in hard can crack. But my insulated chimney has not cracked in 10 years, and is not going to crack simply from using it since the pipe can expand easily into the insulated layer around it. That is, there are indeed plenty of other ways to install a modern clay lined chimney without worrying about expansion cracking. If such options are available in one's area or not I do not know (I live in Europe where Leier and Schiedel make these types of chimneys), but it is a good idea to shop around in any case.

That's great but there is nothing like those prefab insulated masonry chimneys on the market here. I wish we had access to them but we don't.

Our stainless prefab chimneys typically have a 25 or 30 year warranty.

 

[St. Coemgen]

That's great but there is nothing like those prefab insulated masonry chimneys on the market here. I wish we had access to them but we don't.

I suspected that. A pity. It really is a nice system.

https://www.schiedel.com/uk/products/ceramic-system-chimneys/swift/

Here, for reference and for fun, is the new modular chimney being installed when we replaced the roof (you can see by the beam construction how old our house is)

And this is the brick chimney it replaced:

 

[bholler]

I suspected that. A pity. It really is a nice system.

https://www.schiedel.com/uk/products/ceramic-system-chimneys/swift/

Here, for reference and for fun, is the new modular chimney being installed when we replaced the roof (you can see by the beam construction how old our house is)

View attachment 270409

View attachment 270412

And this is the brick chimney it replaced:

View attachment 270410

Yes I have seen pics and videos of them being installed. The stainless prefabs still have a few advantages though. They don't need a foundation. They can run straight off the top of the stove. And they withstand chimney fires better.

 

[EatenByLimestone]

And speed. Class A is much faster. Time is money!

 

[bholler]

And speed. Class A is much faster. Time is money!

Yeah I left that one out

 

[St. Coemgen]

The stainless prefabs still have a few advantages though. They don't need a foundation. They can run straight off the top of the stove. And they withstand chimney fires better.

As I said, I also have a SS chimney as well. And, yes, they are really, really easy to install. They win there in every way. But since I was replacing a old brick chimney in this case, the foundation was already there, so nothing new needed to be added, and the chimney was part of an old wall and the new chimney became part of a new wall, so interior design considerations also were included*** (having a hot metal pipe running up there would have been and would have looked kind of silly -- especially upstairs where a hot pipe would have been in the way and a bit of a hazard actually).

Not sure that SS withstand chimney fires better. Both my chimneys are rated equally to withstand such fires, but the SS I bought (the cheapest) requires a greater clearance to combustibles in case of such a fire. That is the only difference I can see. But, if one has a chimney fire, then the chimney probably (indeed maybe always) needs to be replaced. And yes, then a SS modular one would be easier to replace.

*** Time is indeed money, but living for many years with a well designed room layout is also money well spent.

 

[bholler]

As I said, I also have a SS chimney as well. And, yes, they are really, really easy to install. They win there in every way. But since I was replacing a old brick chimney in this case, the foundation was already there, so nothing new needed to be added, and the chimney was part of an old wall and the new chimney became part of a new wall, so interior design considerations also were included*** (having a hot metal pipe running up there would have been and would have looked kind of silly -- especially upstairs where a hot pipe would have been in the way and a bit of a hazard actually).

Not sure that SS withstand chimney fires better. Both my chimneys are rated equally to withstand such fires, but the SS I bought (the cheapest) requires a greater clearance to combustibles in case of such a fire. That is the only difference I can see. But, if one has a chimney fire, then the chimney probably (indeed maybe always) needs to be replaced. And yes, then a SS modular one would be easier to replace.

*** Time is indeed money, but living for many years with a well designed room layout is also money well spent.

The metal pipe would not be exposed it needs to be enclosed in living areas. And no stainless chimneys rarely need replaced after a chimney fire they withstand high temps and rapid temperature changes far better than masonry.

I know this because inspect many chimneys after fires. It is very rare to find a stainless chimney or stainless lined masonry chimney damaged. It is rare to find clay liners that are not damaged

 

[Zombie]

@bholler With the stove in the corner, the rear corners of the stove are around 14" from the block wall. No combustibles just concrete block. I read on here that unlisted stoves need 36" min. away from combustables but do you think that much radiant heat would be a problem with a block wall? Should I make the pad bigger, put heat shielding up, or both?

 

[bholler]

@bholler With the stove in the corner, the rear corners of the stove are around 14" from the block wall. No combustibles just concrete block. I read on here that unlisted stoves need 36" min. away from combustables but do you think that much radiant heat would be a problem with a block wall? Should I make the pad bigger, put heat shielding up, or both?

No why would it be a problem for the block wall? The main problem is with no insulation you will be sending a large portion of your heat out into the ground surrounding your house instead of heating with it.

 

[Zombie]

with no insulation you will be sending a large portion of your heat out into the ground surrounding your house instead of heating with it.

This is why I asked about the heat shielding. Wasn't sure if the block (since there is an air gap in the block) would hold the heat it worth a crap or not. Thanks for your responses, I'll post up as I go along and look forward to being part of this community.

 

[EatenByLimestone]

A polished heat shield would reflect the heat back into the room like a radiant barrier.

 

[St. Coemgen]

The metal pipe would not be exposed it needs to be enclosed in living areas.

Not allowed here to encase steel chimney pipes except in a brick chimney. Codes. Else they almost always have to go outside or in non-used areas like attics. So you have to usually build a chimney around the steel in living areas, so it is simpler to just install a ceramic one. Unless the upper part of the steel goes through a non living space. Which is what I could do. See below.

Inside:

In the attic:

Both chimneys:

 

[St. Coemgen]

And no stainless chimneys rarely need replaced after a chimney fire they withstand high temps and rapid temperature changes far better than masonry.

I know this because inspect many chimneys after fires. It is very rare to find a stainless chimney or stainless lined masonry chimney damaged. It is rare to find clay liners that are not damaged

I agree that classical masonry will not survive a fire. But.... Since you don't have type of insulated ceramic chimneys, which can expand and avoid expansion damage (the most common type of damage to clay liners), your experience with judging the survivability of the type of ceramic chimney I have may not be valid. They are rated here to indeed survive chimney fires.

But my point was, even with inspection, I would rather be safe than sorry, as inspections can miss things. I would personally replace any chimney after a chimney fire. Despite their ratings on surviability. That is just me..

I have said everything I need to in this thread. Will end my comments here.