Building a new chimney

[matthew555]

the old one was beyond repair supposedly, from the outside water was dripping behind it for 30+ years, ruined walls behind it. outside bricks and mortar pealed off with my pinky.
I am now left with a stone fireplace inside and why would I want to get rid of this? outside I am left with what was attached to the inside stone fireplace, probably 2' from the ground. Actually how can I build something on top of it, I'm sure it needs to be removed, but supposedly it can't be removed because it will remove the inside fireplace?? can this be supported with mortar and build on top of it???
I thought to put in propane, but it looks like the installation of a stove is costly because he would have to go through the remaining masonry to vent it out the back. also the size of the fireplace is 29" high (40" wide) and this isn't big enough for the btu's I need.
so back to the chimney, and supposedly I need a masonry one because that's what I have inside and there's no way to attach it otherwise. chimney would be needed for an propane insert.
To the roof is 8' then another 3' above that. how about out of cinder blocks? any idea how much this is going to cost to build??
any other ideas?
thanks so much!

 

[matthew555]

stone fireplace left inside and what it was attached to outside, also left, I guess partially. If the outside is removed the whole inside is also removed. It's made out of large stones and it's connected.
How can someone build a new chimney, doesn't this all have to be removed? can it be supported properly to hold a new chimney?
Hoping to make the chimney out of the cheapest, cinderblock.
fireplace is 29" high, 40" wide
outside is 8' to roof, another 3' above.
I'm looking at a propane insert to put in space.

The freestanding propane is an issue:
lower BTUs than I need with that height.
the installation through the back, is more,
I don't like the look of what is available, I heard Knightsbridge Napoleon would work, with a back vent.

but the chimney will be a lot more.
how much do you think this chimney will cost approximately??

 

[Destructor]

I used to work with my brother building/rebuilding chimneys. We always took them all the way down. The footings were the only portion we would often reuse but these chimneys were probably older. I suppose your fireplace could be salvaged if the masonry is still good and hard beneath the fireplace and immediately around it. This assumes that it was built properly to begin with.

The fact that it was built in such a way that water was allowed to get behind it is not a good sign. Make sure you have all the proper clearances to framing.

We haven't built chimneys in years so I don't know what current pricing would be. I had my chimney top rebuilt, I don't have staging so I had a friend of my brothers do it, I asked him how much a new masonry fireplace/chimney like mine would cost to build these days. He said arond 8 to 10K. My chimney is 62 years old and other than the top 18" has held up very well. It all comes down to being well built with good brick and a hard mortar mix.

I personally would rebuild the whole thing but maybe after a close inspection a mason may say otherwise. Make sure you use a mason with experience with fireplaces. Proportions and clearances must be closely followed.

On yours heavy tar paper should have been used between the chimney and wood sheeting. Exposed concrete block chimneys do not hold up as well as good brick or stone. Inside they are fine.

 

[matthew555]

I don't think you understand, the chimney has already been taken down. I am left with the bottom of it though. and like I said, it can't be removed because the inside would be removed as well. The inside is large stones.
How about cinder block with stucco covering it? And using this, it still would be 8-10K???

 

[ccmac]

Looking at your current chimney in the picture it does need to be rebuilt. It is not much more at all to take all the brink down and rebuild from the ground up. Your chimney is short so cost won't be crazy. I'd wager you can do it for less than 9K maybe much less. Mine is 4 times that and it cost approximately 15K. The brick work needs to be done right, no decorative stuff at the top of chimney, it only causes issues. Make the whole thing straight up. Top should have a concrete crown with a proper drip edge of 2 inches or more. Use clay tiles to line it and then you can place whatever liner you'd like for your gas stove. Yes I mentioned an additional liner.....not necessary to have two liners but I really like to over build. Also use an elastomeric (sp?) coating, basically a rubberized paint on the crown. This will go a long way in keeping out water infiltration. Water is what kills chimneys in my area. Snow and ice fall onto chimney top, warms up, melts snow, water penetrates cap, night fall comes and temps plumet, water freezes and damage is done! Keep is dry and it'll last much longer. I also used a product called "Chimney Saver" on the brick to help water proof it.

Personally I'd redo the firebox and design everything to accept a wood stove. They look great, heat the house and save you lots of money. Even enough to recoup what you paid to fix the chimney.

Just my opinion....take it for what it's worth....nothing, haha! Good luck!

 

[matthew555]

how can the bottom part be taken out if it's connected to the inside, large stones??
I can't do a wood stove because this is not usually occupied, hoping to get propane and help the electric bill.

 

[begreen]

Maybe remove everything and repair the hole with conventional studding. Then put in a freestanding, direct vent propane heater like this one.
https://rinnai.us/direct-vent-wall-furnace

But first do the math. Propane prices are low now but that is probably temporary. Check on what propane prices were 3-4 yrs ago and make sure going to propane will still be a savings at that old price.

 

[bholler]

The cheapest option would certainly be remove all the masonry, frame the opening closed and do either a freestanding stove or a built in zeroclearance fireplace. But I would bet most of that exterior structure could come out leaving the face inside then rebuild. My guess is that would be close to $10,000 from us at least.

 

[Destructor]

Tear it all down and rebuild. I understand exactly what you were asking. If the interior portion is salvagable which I doubt it is and I wouldn't trust the safety with it remaining, only an experienced fireplace mason can tell you that upon inspection. You have to rebuild the rough opening and the framing above. To do that without ripping down the whole chimney would be almost impossible.

I would build a brand new masonry alcove and chimney as already suggested.

 

[bholler]

If the interior portion is salvagable which I doubt it is and I wouldn't trust the safety with it remaining, only an experienced fireplace mason can tell you that upon inspection.

I agree it is hard to say with out inspecting but almost all i have worked on you can leave the face intact and rebuild the structure behind it. including the firebox

 

[St. Coemgen]

I have had built two modular, insulated, ceramic lined cinder block chimneys. They were cheaper than on site, hand made masonry chimneys for me, but local prices my vary. I am very happy with them. No complaints so far.

Just be sure the chimney follows all local codes. Ours does. In fact, all new chimneys here now must be of this type or built of special insulated brick.

 

[matthew555]

tearing down the inside is not an option. how am I going to know if in fact the inside is salvageable to use for a wood fireplace or a propane insert or (a vent free gas logs without a chimney)?
I've already had masons look at it.
If it IS ok
(and how will I know that with certainty???)
and the structure outside is not stable, how about building the outside structure on the outside of it, making the bottom bigger, stabilizing it and then build up? Like making a frame around it, keeping the inside intact. Could that work?

 

[bholler]

tearing down the inside is not an option. how am I going to know if in fact the inside is salvageable to use for a wood fireplace or a propane insert or (a vent free gas logs without a chimney)?

It will not be. You will probably be able to brace that face and remove the structure behind it but it will need a masonry structure put in behind it again.

If it IS ok
(and how will I know that with certainty???)

You will know for certain after you take that outside structure down if the face is still standing it was fine if it is not it was not. There is no way to know for sure until you start doing it.

 

[matthew555]

well the person that took the outside down wouldn't take the bottom outside structure down because he said the inside will come down. so from what you said and what he said, it's not good.
I know I"m pressing this but please bare with me.... the mantel inside is large stones. on the outside there are no stones. couldn't all cement come out until you reach the stones?
just so I understand, mortar can become filled with water and basically not be supportive? so if the inside of the fireplace had water that's why it's beyond repair (like what happened to the outside)??

 

[Destructor]

Does the front face bear directly on the footing or is there a block wall beneath it? If you have a basement there will be an inner and outer hearth. The inner hearth spans across an empty space usually used as an ash pit. The outer hearth cantilevers beyond the support wall in the basement. It looks like you have a basement.

The chimney structure beneath the inner and outer hearth must remain in place or everything will become unstable. If you have no basement and everything is mostly solid beneath your firebox and hearth then maybe you can leave most of it in place and remove the masonry around the perimeter. Also you will want to tie that front wall back into whatever new structure is built behind it.

Can it be deturmined if the outer most masonry still in place is a veneer or part of the support structure beneath your firebox and inner hearth.

 

[matthew555]

Does the front face bear directly on the footing or is there a block wall beneath it?

I don't know.
I have a basement, beneath the fireplace is a rectangle of cinderblock (the rest of the wall is poured concrete). I was told that it used to be open but it was closed because of the water problem. Not certain if that is true.
"The chimney structure beneath the inner and outer hearth must remain in place or everything will become unstable."
when you say structure, how high is that???

"Can it be deturmined if the outer most masonry still in place is a veneer or part of the support structure beneath your firebox and inner hearth."
how can I find that out?? can I leave it and build on the outside of it? like box it in?

thanks

 

[Destructor]

It looks like what remains below is stuccoed concrete block? If so then it is most likely supporting your fireplace above and must remain in place. Maybe chip out half a block and see what's behind. The rectangle of block you mentioned in the basement is supporting the front portion of the hearth. The front wall is also bearing on that heart/wall.

I don't think you can get out of this easily. Salvaging what you have will be alot of effort but with enough effort almost anything can be done. Starting over allows you to do whatever you want, of course there is always the issue of budget. Whatever you do make sure a proper cricket is built at the roof.

 

[matthew555]

thanks,
I think that's correct...what is left is stuccoed concrete block.
I can't keep it and build around it so it will be secure and watertight???

I can't tear down the inside. you are the first person to mention the cricket, (since the person that tore it down). As I understand it, this is what is needed so water won't get behind chimney? When you say I need a cricket, I think you mean if I build a chimney? correct?

so what exactly is the effort that is needed to keep the front?

if I can't get this to work I believe this is what I believe I am left with:

close what is left outside with outside walls, blocking it in.
put a freestanding stove in front (although I thought it would look better to be inside) the existing fireplace and vent it out the back through the current masonry. So far, I believe there is one unit capable of getting enough btu's, it has some extra piece that makes the connection not loose btu's when venting out back instead of the top. napoleon knightsbridge.
What would be better is..... why the vent can't be in the fireplace and vent it up, if it's deep enough?

I was told I can put ventfree propane logs in fireplace if the masonry is ok. Question is, can I get what is there sealed up and make that a safe option?
If it's not safe, put a ventfree propane unit inside???

how about an electric unit inside?

 

[matthew555]

what is inside the living room, where the stone is, the mortar comes off easily, it just breaks apart and crumbles. That's waterlogged? Is there a way to fix that? Or will the whole thing just fall down one day?

 

[bholler]

what is inside the living room, where the stone is, the mortar comes off easily, it just breaks apart and crumbles.

If the mortar on the interior face has deteriorated that badly there is nothing worth saving and it will not be able to stand on its own anyway

 

[Destructor]

It seems like the mortar mix wasn't good to begin with. Moisture alone shouldn't ruin mortar. Many sewers were built of brick and mortar and are still good today. Disassemble the whole thing and build something new. If you go with masonry you can save a little money on materials reusing some of what was demolished as fill material. Maybe the stone on the interior will clean up well enough to reuse. If you don't rebuild the fireplace I'd build an alcove that could accept a wood stove or gas stove.

 

[matthew555]

even if I don't use it as a fireplace, just put a freestanding stove, the whole thing will fall down on it's own?
it's been like this probably 30 years.

 

[bholler]

even if I don't use it as a fireplace, just put a freestanding stove, the whole thing will fall down on it's own?
it's been like this probably 30 years.

we don't know we haven't seen it. It is possible if the mortar is that bad

 

[matthew555]

Sorry for beating this to death, but this is just beyond devastating,
Is it possible to fix the mortar, replace only the mortar? Can I put a freestanding propane stove or any other options besides tearing down the whole thing?

 

[begreen]

Sounds like you need a good, professional on site to determine if anything is salvageable. I would check around for the best local masons and ask for their assessments. We have not even seen the inside masonry and can not assess what is savable over the internet.