Thoughts on removing chimney stack

Snigla · 23 Aug 2011 at 12:09 PM

Hello!
We live in a typical 70s house where there was once an oil boiler (currently geothermal heat)... and therefore also a chimney that goes through the whole house. Today, we don't use it in any way, even though there is a brick fireplace in the basement (completely open... basically "heating for the birds" open - no insert, and we don't think it's worth the money to buy one either, since we're not that keen on coziness and we wouldn't gain anything heat-economically from it either).

Can you tear down something like that? Or does it have any load-bearing function in the house?

I think, for example, the floor is framed around the chimney on the entrance floor (in the basement it stands directly on the concrete)... because all the houses on the street have the same problem with a sunken floor around it (i.e., creaking, bent parquet, etc.).

How big of a project is it really? New framing, flooring materials, and so on are understandable... but is there anything else that comes with it? I assume the roof must be sealed off in some way unless, for example, you put a metal cap there for ventilation or something similar...? (Currently, it's bricked up, as mentioned.)

Has anyone done something similar? Or seen someone else do it? Tips and thoughts?

Best regards, Sandra

byggarätt · 23 Aug 2011 at 5:20 PM

Removing the chimney is unwise and load-bearing parts are often resting on it.
Ventilation goes through the chimney, and if the chimney is not used, it can lead to bad odors and mold.

norrbottenstorpet · 23 Aug 2011 at 5:40 PM

It can't be said for certain without seeing it, maybe break it up and check. But in a house from the 70s, I wouldn't think that any part of the intermediate floor is hanging on the chimney stack, so from that aspect, it's likely okay to remove the chimney stack. What kind of ventilation system does the house have and how will it function when the chimney stack is removed?

Avemo · 23 Aug 2011 at 6:36 PM

I also don't think it has any load-bearing function in the house. You can find that in old houses, but as far as I know, it's no longer allowed. It will obviously leave a hole through the entire house after it's removed. It seems to be a big job to remove it, and all ceilings and floors it passes through must be addressed. The question is, as mentioned, whether it still has any function for ventilation. Lastly, the question is why you want to remove it. It seems to be a big job for a small gain in living space.

Erik

Snigla · 25 Aug 2011 at 1:21 PM

byggarätt said:
Removing the chimney is unwise as load-bearing parts are often supported on it. Ventilation goes through the chimney and if the chimney is not used, it can lead to bad odors and mold.

As I cautiously mentioned, I don't think it is load-bearing, as far as I can tell from the building plans (original documents) they have done some kind of framing around the chimney.. and now that is what causes the floors on the whole street to sag there.. because it doesn't attach to anything (in that way the floor would have been better around the chimney IF it had been attached to it?)

We have more chimneys solely for ventilation too.. and the ventilation is not particularly satisfactory today as it is (in the chimney).. the chimney is not used (never used the open fireplace and we have geothermal heating today). So we have already booked some ventilation help (to see how we can get the air moving again.. especially in the basement)

Thanks for the thoughts!
Best regards, Sandra

Snigla · 25 Aug 2011 at 1:28 PM

norrbottenstorpet said:
It's hard to say for sure without seeing it, maybe break it up and check. But in a 70s house, I wouldn't think that any part of the middle floor is hanging on the chimney, so from that perspective, it's probably okay to remove the chimney. What kind of ventilation system does the house have, and how will it work when the chimney is removed?

I should have checked more carefully when we tore up one floor (one side of the chimney).. but as I said, I think they've framed around it (unstable floor..).. we actually need to tear down two more rooms where the floor has given way a bit around the chimney.. (that is, it hasn't collapsed.. just that it's sunk a few cm and it makes the parquet rise and squeak and crack if you even breathe).

The house doesn't have anything mechanical, but I would probably say we don't have any ventilation at all right now.. after we switched from an oil burner (which only ran on electricity) to geothermal heat, the air has changed quite a bit.. so we have booked a consultation hour to go through some different options and do some measuring.. personally, I would actually want to have a mechanical system but that also costs.. so we'll see what it ends up with..

We have a bunch of ventilation thingamabobs (can't remember what they're called.. but those you screw open or close.. that are on the walls in the basement).. no Pax fans or anything in the house.. the bathroom is to be renovated and then of course a couple of those will be added (also the laundry room/shower in the basement will get one)..

Best regards, Sandra

Snigla · 25 Aug 2011 at 1:36 PM

Avemo said:
I also don't think it has any supporting function in the house. You can find that in old houses, but nowadays it is, as far as I know, not allowed. It will obviously leave a hole through the entire house. It's likely a big job to remove it, and all the ceilings and floors it passes through need to be addressed. The question, as mentioned, is whether it still has any function for ventilation. Finally, there's the question of why you want to remove it. It's likely a big job for a small gain in living space.

Erik

Yes, it's the work around tearing down the chimney that's a bit daunting, how much have I in my vivid imagination forgotten that I'll need to address afterward, you know.. that's why I dropped a little thought question in here

Here you can get some thoughts and advice.. (and tips and tricks)

It's just that... the perfect dream house isn't always purchased.. but you have still bought a house where you like the neighborhood.. with the plot.. and the size of the house (and possibilities).. but then you have a chimney that puts a wrench in the works.. on two floors.. it along with the fireplace, I just find it blocking the reallocation of space in the house! If the chimney could fly.. the attic part and the visible chimney outside (with the cap and everything) could happily remain, but it doesn’t quite work that way.. I realize that too haha... but then the question is..

how much extra work is there after you've removed the chimney (which is probably a heck of a dirty job by itself).. the floors on the entrance level (that half) need to be torn up and re-framed anyway - even if we don't remove the chimney.. the basement is also in the process of being remodeled and, for example, will have the ceiling replaced and be replastered inside.. the only thing not planned is to redo the outer roof in some way.. or do anything in the attic (other than possibly ventilation).. and maybe that's where the extra work comes in?

Have a nice day,
Best regards, Sandra

Lennartsson · 28 Aug 2011 at 10:27 PM

Hello.
I tore down the chimney breast in my house that I'm renovating. I can say that it was the best decision I made. It was just in the way anyway

It was quite large, 180 wide and about 70 deep. This is a hundred-year-old house and there was nothing load-bearing against the chimney breast other than having to support a roof truss that was against it. I will solve the ventilation with mechanical exhaust.

Best regards, Marcus

Snigla · 31 Aug 2011 at 4:26 PM

Lennartsson: that wasn't a small chimney stack.. ours is maybe 70x60 cm.. I assume there was quite a bit of debris? was it heavy/difficult to remove the masonry so to speak? (how did you handle it at the roof?)

Tornhill 2 · 1 Sep 2011 at 10:25 AM

Hello Snigla.

Although I've never dismantled a chimney in such a new house, chimneys are usually built with such weak (low-cement) mortar that they are very easy to take down. However, it is dustier than you could ever imagine.

A few thoughts then:
1. If the floor sags around the chimney and if you never use it (at least in the basement), I would just remove the fireplace (to avoid unpleasant mistakes..) then I would lift the floor around the chimney stack to 2mm above the desired level with a prop and then fasten angle profiles to the chimney for the floor to rest on. That would probably solve your issues with sinking and creaking floors.
2. If it works for the floor plan, I would leave the chimney in place and put a fan on the outlet. That way, you solve the ventilation. There are special chimney fans, though they might be unnecessarily expensive for you since you won't be running any exhaust gases through it. You can run the power through one of the pipes.

/ Fredrik

Mullbär · 1 Sep 2011 at 11:15 AM

If you ever decide to sell the house, a chimney can have unexpected value for those interested in buying it. Besides, something is "missing" from a house without a chimney! I wouldn't have attempted to remove it! Big job, lots of dust, and potentially something that could decrease the value of the house! But on the other hand, if that is what you want, then the chimney is probably freestanding in a house from the 70s. If I were you and absolutely wanted to demolish it, I would probably start by lifting some of the floors around the chimney and see what it looks like. However, we had to do the opposite. In our old house, the chimneys were removed in favor of electric heating, and when we moved in, it was a job to build new ones instead. That was also a lot of dust and hard work!

Snigla · 1 Sep 2011 at 1:51 PM

Mullbär said:
If you ever plan to sell the house, a chimney can have an unexpected value for those interested in the house. Additionally, something is "missing" from a house without a chimney! I wouldn't have taken it down! Big job, lots of dust, and something that might lower the house's value!
But on the other hand, if that's what you want, the chimney might probably be freestanding in a house from the 70s. If I were you and absolutely wanted to demolish it, I would probably start by lifting the floors around the chimney and see what it looks like.
However, we had to do the opposite. In our old house, the chimneys were removed in favor of electric heating; when we moved in, it was a chore to build new ones instead. It was also very dusty and hard work!

Yes, I know we all look for different things when house hunting; I actually love fireplaces... I had tiled stoves in every room in a house I lived in before... incredibly charming and cozy in winter... However, the chimney doesn't really serve much function here in our house, we've never actually used it... the only thing we've had to do is clear out bird nests in the flue... (now we've bought one of those guards with bird netting).

Our house does at least have some metal chimneys for ventilation... so the roof won't be completely bare even if (IF) we were to take down the chimney...

The only time I can see us possibly using the fireplace is if some kind person nearby gives away a fireplace insert... (those things are damn expensive...) because then we could burn for more than just the crows... but the new price for such an insert is not justifiable for us to spend... as our entire heating needs are met by geothermal heat (so we can't really save money by burning for heat's sake).

Well... we'll just have to think a bit about it...
Best regards, Sandra

Snigla · 1 Sep 2011 at 2:00 PM

Tornhill 2 said:
Hi Snigla.

I have never demolished a chimney in such a new house, but chimneys are usually built with such weak (cement-poor) mortar that they are very easy to take down. However, it is dustier than you can ever imagine.

Some thoughts then:
1. If the floor sags around the chimney and if you never use it (at least in the basement), I would just remove the fireplace (to avoid unpleasant mistakes..) then I would lift the floor around the chimney stack, to 2mm above the desired level, with a stamp and then screw in angle profiles into the chimney, which the floor can rest on. That would probably solve your problems with sinking and creaking floors.
2. If it works for the floor plan, I would let the chimney remain, and put a fan on the exhaust. That way you solve the ventilation. There are special smoke fans, although they might be unnecessarily expensive for you since you will not be running any smoke through it. Run the power up through one of the pipes.

/ Fredrik

A bit of a hassle no matter how you twist and turn the whole thing.. hehe (not that I thought otherwise either..).. too bad you can't snap your fingers a bit.. and get it just as you wanted

We have a built fireplace in the basement, quite a large one..and it is not under the chimney stack but rather behind it.. besides that, nothing is connected to the chimney stack (yes, there are more pipes so to speak, but for example, the old boiler is removed and that pipe is rusted and we probably have one or a few pipes for ventilation).

We have considered doing a little trick there with the chimney and ventilation, but we have booked a consultation hour to discuss alternatives.. the air must start to move throughout the house, I think for sure.. sure we can ventilate upstairs with doors and windows but the air is a little stagnant..(which apparently is also not so unusual in 70s houses).

Best regards Sandra

Lennartsson · 1 Sep 2011 at 3:13 PM

The stones were very easy to chip away one by one. We stacked the stones on pallets and sold them. It is definitely an advantage to be a few people. The remains like mortar and broken stones we just buried on the property. Then we switched out a truss that was right in the chimney stack. The roof is metal at the moment, so we just laid new sheets. The roof is going to be replaced next year.

/Marcus

byggarätt · 11 Sep 2011 at 4:49 PM

Hello, it sounds like you've understood that ventilation is important and don't confuse supply air ventilation with exhaust air ventilation... the exhaust air goes through the chimney and needs heat for the natural draft to function...
When you don't use the chimney it is cold and works less efficiently, which is why you may need extra ventilation...
My suggestion is to keep the chimney and install a fireplace insert or an alcohol-powered stove... then you'll see that you get both coziness and ventilation...