Concrete Chimney Options

[SasWalk]

Hello everyone, I would love people's thoughts on replacing or simply lining my existing concrete block chimney.

Here is my situation. I am hopefully going to be installing a new wood stove in my house this year, and I think I have settled on a BK Ashford 30.2. However, before this happens we are having our current chimney inspected for a SS liner. The current chimney was added to the house 30-40 years ago on the exterior of the gable-end, and made from concrete chimney blocks. It was built on a concrete slab. It has a, roughly, 8x12, flue opening with a pumice flue liner - at least the chimney sweep told me it was pumice. Current chimney height is about 18' from where the current thimble enters the chimney.

The chimney sweep stated that there are some significant cracks in the chimney above the roof-line, as well as a few lower on the chimney. Additionally, the chimney does not reach a height above the roof to meet the 3-2-10 rule, so I would need to add height to satisfy that and meet the height demanded by the BK Ashford stove.

The sweep gave me two options. First, install a liner in the masonry chimney with added length out of the top. Second, and his preference, is to demolish the masonry chimney and install a Class-A chimney in it's place.

I don't like the concrete chimney and like the idea of replacing it, but It will be much less expensive right now to simply line the current chimney.

Please let me know your thoughts, and tell me if I need to give any more information.

 

[Highbeam]

Your sweep is right, tear that junk down. I also removed a cracked masonry chimney to replace with a pipe and don’t regret it a bit.

It’s super easy to remove that old chimney since it is literally a column of stacked blocks with no fireplace. You could almost just shove it over.

Get a bid breakdown since the price shouldn’t be that much more to go to a pipe.

 

[bholler]

Your sweep is right, tear that junk down. I also removed a cracked masonry chimney to replace with a pipe and don’t regret it a bit.

It’s super easy to remove that old chimney since it is literally a column of stacked blocks with no fireplace. You could almost just shove it over.

Get a bid breakdown since the price shouldn’t be that much more to go to a pipe.

It is now quite a bit more chimney pipe has gone through the roof.

 

[bholler]

Hello everyone, I would love people's thoughts on replacing or simply lining my existing concrete block chimney.

Here is my situation. I am hopefully going to be installing a new wood stove in my house this year, and I think I have settled on a BK Ashford 30.2. However, before this happens we are having our current chimney inspected for a SS liner. The current chimney was added to the house 30-40 years ago on the exterior of the gable-end, and made from concrete chimney blocks. It was built on a concrete slab. It has a, roughly, 8x12, flue opening with a pumice flue liner - at least the chimney sweep told me it was pumice. Current chimney height is about 18' from where the current thimble enters the chimney.

The chimney sweep stated that there are some significant cracks in the chimney above the roof-line, as well as a few lower on the chimney. Additionally, the chimney does not reach a height above the roof to meet the 3-2-10 rule, so I would need to add height to satisfy that and meet the height demanded by the BK Ashford stove.

The sweep gave me two options. First, install a liner in the masonry chimney with added length out of the top. Second, and his preference, is to demolish the masonry chimney and install a Class-A chimney in it's place.

I don't like the concrete chimney and like the idea of replacing it, but It will be much less expensive right now to simply line the current chimney.

Please let me know your thoughts, and tell me if I need to give any more information.

View attachment 307874View attachment 307875

I can't see any significant cracking in the pictures but that will really be the determining factor. If the chimney is cracked badly it's not worth lining it.

Another thing to consider is seismic activity. Here that isn't much of an issue so using masonry chimneys isn't a bad option at all. The perform just as well. But that may not be the case in your area

 

[begreen]

The sweep gave me two options. First, install a liner in the masonry chimney with added length out of the top.

Will the liner be insulated with this option? If not, then don't do it. The flue gases will cool too much in an uninsulated outdoor chimney and creosote accumulation can become an issue. BK stoves have cooler flue gases and really should have insulated flue systems for the best performance and safety. My vote is for option 2 unless an insulated 6" stainless liner is put in the cement block chimney. Note that typically these block chimneys have an 8x8 tile liner in them. If so, it will need to be broken out and removed.

 

[armanidog]

"The chimney sweep stated that there are some significant cracks in the chimney above the roof-line"

I vote for removal. If the metal chimney is too expensive I would at least replace the cracked blocks above the roof and add a chimney cap.

 

[bholler]

Will the liner be insulated with this option? If not, then don't do it. The flue gases will cool too much in an uninsulated outdoor chimney and creosote accumulation can become an issue. BK stoves have cooler flue gases and really should have insulated flue systems for the best performance and safety. My vote is for option 2 unless an insulated 6" stainless liner is put in the cement block chimney. Note that typically these block chimneys have an 8x8 tile liner in them. If so, it will need to be broken out and removed.

This is a rectangle block chimney so 8x12 liners which leaves oval as an option. But i would probably still remove the clay and do round if the chimney is worth it and there aren't seismic concerns

 

[bholler]

"The chimney sweep stated that there are some significant cracks in the chimney above the roof-line"

I vote for removal. If the metal chimney is too expensive I would at least replace the cracked blocks above the roof and add a chimney cap.

At current class a chimney prices that may still be a cheaper option. It would be in this area atleast

 

[SasWalk]

At current class a chimney prices that may still be a cheaper option. It would be in this area atleast

I'll have to see what the official estimate is. During his visit he stated $300 for a 4' stick of Class A.

 

[SasWalk]

Will the liner be insulated with this option? If not, then don't do it. The flue gases will cool too much in an uninsulated outdoor chimney and creosote accumulation can become an issue. BK stoves have cooler flue gases and really should have insulated flue systems for the best performance and safety. My vote is for option 2 unless an insulated 6" stainless liner is put in the cement block chimney. Note that typically these block chimneys have an 8x8 tile liner in them. If so, it will need to be broken out and removed.

I don't know if the liner will be insulated, but I would want it to be. The chimney has a rectangular opening of, roughly 8x10. The sweep said it is a pumice liner, but I don't know. Will an insulated 6" liner not fit in an 8" wide opening?

 

[SasWalk]

I can't see any significant cracking in the pictures but that will really be the determining factor. If the chimney is cracked badly it's not worth lining it.

Another thing to consider is seismic activity. Here that isn't much of an issue so using masonry chimneys isn't a bad option at all. The perform just as well. But that may not be the case in your area

I can see a long crack running through multiple blocks from the ground. The sweep was concerned enough that he didn't want to spend too much time at the top with his ladder resting against the top of the chimney. I don't know enough to determine whether a crack is minor or significant.

I do have seismic concerns, as I live in Western Oregon.

 

[bholler]

I can see a long crack running through multiple blocks from the ground. The sweep was concerned enough that he didn't want to spend too much time at the top with his ladder resting against the top of the chimney. I don't know enough to determine whether a crack is minor or significant.

I do have seismic concerns, as I live in Western Oregon.

In that case i would recommend replacing it. It just doesn't make sense to put a liner in a compromised chimney.

 

[begreen]

I don't know if the liner will be insulated, but I would want it to be. The chimney has a rectangular opening of, roughly 8x10. The sweep said it is a pumice liner, but I don't know. Will an insulated 6" liner not fit in an 8" wide opening?

8" ID is tight. If too tight, an oval, insulated liner can be installed, but it sounds like this chimney as other defects as well.

I can see a long crack running through multiple blocks from the ground. The sweep was concerned enough that he didn't want to spend too much time at the top with his ladder resting against the top of the chimney. I don't know enough to determine whether a crack is minor or significant.

I do have seismic concerns, as I live in Western Oregon.

I got rid of all masonry chimneys in our house for this reason. The earthquake of 2000 rotated the top of our chimney 45º. The only thing that kept it in place was the rigid liner and glued-on top plate. Our neighbor's chimney toppled. Thankfully this was not when a fire was going on.

 

[Highbeam]

So 300$ per 4 foot section, you need four of those so 1200$. The 16’ insulated liner isn’t cheap either. You’ll need other chimney parts but those are about the same for liner vs. pipe.

I don’t see that as “through the roof” even though I love the pun! This is a 5000$ stove.

 

[begreen]

So 300$ per 4 foot section, you need four of those so 1200$. The 16’ insulated liner isn’t cheap either. You’ll need other chimney parts but those are about the same for liner vs. pipe.

I don’t see that as “through the roof” even though I love the pun! This is a 5000$ stove.

There is also the cost of the $400 Tee and the $200 thimble.

In this situation, if it's a total chimney replacement I would be rethinking the stove location if it improves anything and definitely would be closely examining the option of an interior chimney, going up through the roof.

 

[bholler]

So 300$ per 4 foot section, you need four of those so 1200$. The 16’ insulated liner isn’t cheap either. You’ll need other chimney parts but those are about the same for liner vs. pipe.

I don’t see that as “through the roof” even though I love the pun! This is a 5000$ stove.

By the time you add all the components demo of the chimney finishing of the space where the chimney was etc i would expect a minimum of $3500 probably more. Now that could certainly be reduced by going straight up and out as begreen suggested.

And no the components are nowhere near the same price for liner and prefab chimney. And there aren't nearly as many components for a liner. But regardless i don't think it makes sense to line this chimney.

 

[SasWalk]

In this situation, if it's a total chimney replacement I would be rethinking the stove location if it improves anything and definitely would be closely examining the option of an interior chimney, going up through the roof.

Unfortunately, the layout of our 1st floor doesn't allow for the suitable placement of the stove anywhere else. Going through the roof necessitates the stove pipe running through upstairs bedrooms - neither my wife or I like that idea - and there really isn't enough space for that.

 

[begreen]

Unfortunately, the layout of our 1st floor doesn't allow for the suitable placement of the stove anywhere else. Going through the roof necessitates the stove pipe running through upstairs bedrooms - neither my wife or I like that idea - and there really isn't enough space for that.

Sometimes that is the case. I moved our stove so that the chimney pipe goes up through a bedroom closet but that's not always an option.

 

[HearhFlame]

I'm just lurking here.
Pretty sure I'm set on pellet stove at this point mainly because i have been quoted a price of
$12 000 ($3800 would be for the stove- Green Mountain 60 i think) for chimney tru the roof.
I got 2 storey house with around 8' attick so chimney would have to clear 2' past that.Therebis roof right above the firt flooe ceiling where chimny would go tru the roof so i wouldn't have to go tru the second floor bedrooms.
Does the price seem reasonable?

 

[njk4o5]

I'm just lurking here.
Pretty sure I'm set on pellet stove at this point mainly because i have been quoted a price of
$12 000 ($3800 would be for the stove- Green Mountain 60 i think) for chimney tru the roof.
I got 2 storey house with around 8' attick so chimney would have to clear 2' past that.Therebis roof right above the firt flooe ceiling where chimny would go tru the roof so i wouldn't have to go tru the second floor bedrooms.
Does the price seem reasonable?

I have a pellet stove at one of my homes and a wood stove at the other. I was kindof in the same boat as you with a rough shape chimney and went with the pellet stove. It was way easier and cheaper to install and has done its job taking the load off the oil boiler this winter. But it throws nowhere near the amount of heat of even a small woodstove would. I feel like pellet stove max BTU outputs are exaggerated and woodstove BTU outputs are under-rated.

Wood stoves can be pretty much free heat if you have some land and willing to get some exercise plus they still heat without power during storms . Pellet stoves you still have to buy pellets (which are getting more and more $$ every year), clean the hopper and fill it once a day or so. Then there's figuring out which brand pellets are good vs bad.

Can you just get the top of your chimney redone where it is cracked? That shouldn't be to pricey. Always get at least 3 quotes for work.

 

[EatenByLimestone]

I'm just lurking here.
Pretty sure I'm set on pellet stove at this point mainly because i have been quoted a price of
$12 000 ($3800 would be for the stove- Green Mountain 60 i think) for chimney tru the roof.
I got 2 storey house with around 8' attick so chimney would have to clear 2' past that.Therebis roof right above the firt flooe ceiling where chimny would go tru the roof so i wouldn't have to go tru the second floor bedrooms.
Does the price seem reasonable?

Thats hard to say since every house and situation is different. You will be needing an awful lot of Class A pipe. Thats not cheap. The installer has to put in a hearth, cut through the first floor ceiling, second floor ceiling, and roof. Any structural members cut through will need to be secured so they don't fail. Any wires or pipes encountered will have to be moved. A chase will have to be built around the Class A on the second floor. We don't know your roof pitch or what it's made of. That can lead to complications. We don't know what the ground is like. Are you on a hill and it'd be tough to set a ladder?

And there's the price of the stove.

Whenever there are unknowns, the contractor has to pretend there will be problems. Get multiple quotes, thats probably the best way to figure out if his quote is reasonable.

You could do the work yourself too. That'd likely save thousands, but there are skills needed to deal with any issues that might be found/pop up. You could probably rent any tools/equipment you don't have that is needed.

 

[begreen]

I'm just lurking here.
Pretty sure I'm set on pellet stove at this point mainly because i have been quoted a price of
$12 000 ($3800 would be for the stove- Green Mountain 60 i think) for chimney tru the roof.
I got 2 storey house with around 8' attick so chimney would have to clear 2' past that.Therebis roof right above the firt flooe ceiling where chimny would go tru the roof so i wouldn't have to go tru the second floor bedrooms.
Does the price seem reasonable?

$8k for a chimney and stovepipe sounds high.