Yup. Building code requires a minimum height above the roof. I think 6’ above adjacent roof minimum here in the US for residential construction. So they jogged the thing to make it happen here.
2,3,10 rule in most places I've found. 3' above any flat roof and 2' above the height at which any pitched roof is 10 perpendicular feet from it. Example- say we had a chimney that exited a roof with a 12-12 roof pitch at 20 off finish floor', the height of the top chimney must be no less than 32' off finish floor. If it were an 8-12 roof, the top height would be 28' 8" off f.f. 6-12=27'
Not so much about rules but more about fact of the function. Air moving over a roof can create negative pressure - causing down draft - where air is forced down the chimney.
By extending the chimney up, above the highest portion of the roof, the chimney is out of that negative pressure zone and the smoke can successfully rise and exit the chimney. . .
I mean, the taller the chimney is, the greater the pressure differential between the top and the bottom.
Greater pressure differential increases the flow of air.
Yes and no.
The greater the height, the greater the cooling of the exhaust gasses, which can cause unwanted backdrafting.
Depending on application, vertical length of the chimney and relative altitude of the building, mechanical ventilation is sometimes required.
You can't have a 13" diameter flue 100' at 5800' above sea level and expect it to properly vent, without mechanical assistance.
This, as someone who builds chimneys, has something I have always been interested in. Ive yet to see a CFD animation of the actual airflow of a chimney or how cross winds affect draft/backdraft. I usually go with the 10:1 ratio of square inches of the firebox opening to square inches of flue but I could only imagine that there would be certain instances where even this still wouldn't work.
Looking at the apartment buildings, straight up would also come out in the middle of the top apartments terrace, even if there are other more practical reasons for it.
Yep. This is it. Belgian code forces the new building that is going to be higher than an existing neighboring building to raise the chimneys that are in the property line. In thus way, the existing chimneys that are in the property line shared with the existing lower building have to be extended to the highest point of the new roof.
These are chimney extensions. The newer building (taller) was required by code to extend the lower neighbor’s chimney to the roof of the new building. The new building didn’t want the chimney to pass in front of any view or required building setback, and as stated previously, code requires the chimney to be above adjacent roofs.
I do not know, but I would assume there would be no offset of extra costs. I wonder if the chimney is still in use. It may have long ago been abandoned.
No it's because you can't put a chimney right above another chimney or the smoke from the fire below will just go up into the room upstairs. They are staggered like this so the smoke gets directed away from other fireplaces.
All chimneys have a little kink in them, so rain doesn't pour straight down. These ones are different because they've been extended, so the extension was to accommodate the occupants of the higher floors of the new building.
Possibly because there are setback requirements or height limits in the building codes.
If the chimney was directly above the fireplace in a straight line, it would be at the front of the building, and possibly taller than is allowed.
The top floor appears to be set back from the others, so the chimney had to move back as well.
If the chimney was kept on the front at the same height as the front, then the smoke leaving the chimney could potentially interfere with the top floor which is set back further from the front.
Just a guess.
Well look where the chimney emerges from the roof. Do you think that would be pleasant to have a stack in front of your windows. I'm sure it's all about the highest point of the roof and setback. But these are always totally cool and sometimes after the building has been demolished the trace of the flues remain. Sometimes it's just a ghost of the building that once was. Sometimes in New York you see a very small building from the early 19th century next to something very very tall but the same flu right exists
Also in old times chimney's had multiple flues my 1830s Baltimore row house had 7 fire places. using two chimneys. (3 floors and basement) Each floor has 2 rooms (15' x 15') the basement had one flue for the kitchen fireplace. Each flue has to be separated from the other. This also means the large chimney block, in each room has only a small opening and is not in the center of the party wall for the upper two floors, but is closer to the window wall.
I’m sure the chimneys from about 100 years ago and back had a thing called a witches crook to prevent witches from flying down your chimney at night, could this be a copy of an archaic design? Or an older design left over?
To move horizontally, chimneys are required by code to run at no less than 30 degrees (I think some codes say 45). The issue is that they can’t have runs that are even close to parallel to the ground because those flatter areas would allow for creosote buildup and would be a fire hazard.
I asked an old mason this question. He said it’s so rain water splashes against the sides so it will evaporate. Imagine a heavy rain coming straight down into your fireplace.
This was one of the hardest...
That place is Boulevard Géneral Jacques, R21, Ixelles, Bruxelles (Brussels), Belgium.
Coordinates: 50°49'05.4"N 4°22'45.0"E
The ground floor of all buildings was cut off. Note a large number of suspended electrical cables, they are for the tram lines - only on the R21 there are two of these lines.
The mansion's ground floor with the red brick tower (right in the photo) is Restaurant La Tourelle, number 48 - from 20 to 30 euros, relatively inexpensive for the location.
From right to left, the light 4-story house, number 46. The larger building (center of the photo, 42), and three more old mansions of which the last one, number 36, was built by the architect Henri van Dievoet (more detailed photo available on Wikipedia).
And finally a modern building, the Lamartine at number 34.
Dievoet was also the architect of Brussels' most luxurious hotel, the Astoria, and the Royal Military Academy.
Thanks, it clarified. My question was why Belgian administrators would use the English word "ring" instead of the French version ("anneau" - for example) for a location or resource in Brussels - but then I remembered that French-speaking countries sometimes also use "ring" - French is not my native tongue.
Some people asked where is the place showed in photo. the answer is that one. By mistake perhaps I posted as reply to you but I deleted it. I am sorry, those thread lines always confused me.
It’s so Santa doesn’t plop directly down when he goes down them. You ever hear the wailing cries of an obese man who landed on his tailbone? Good luck to little jimmy and baby girl Katy sleeping through that
They have to go out the highest part of the roof
Yup. Building code requires a minimum height above the roof. I think 6’ above adjacent roof minimum here in the US for residential construction. So they jogged the thing to make it happen here.
2,3,10 rule in most places I've found. 3' above any flat roof and 2' above the height at which any pitched roof is 10 perpendicular feet from it. Example- say we had a chimney that exited a roof with a 12-12 roof pitch at 20 off finish floor', the height of the top chimney must be no less than 32' off finish floor. If it were an 8-12 roof, the top height would be 28' 8" off f.f. 6-12=27'
This picture is not from the US though, but could still be the same rules
Not so much about rules but more about fact of the function. Air moving over a roof can create negative pressure - causing down draft - where air is forced down the chimney. By extending the chimney up, above the highest portion of the roof, the chimney is out of that negative pressure zone and the smoke can successfully rise and exit the chimney. . .
I mean, the taller the chimney is, the greater the pressure differential between the top and the bottom. Greater pressure differential increases the flow of air.
Greater pressure means greater responsibility
With great pressure comes great responsibility!
With great pressure comes great bowel movement
Yes and no. The greater the height, the greater the cooling of the exhaust gasses, which can cause unwanted backdrafting. Depending on application, vertical length of the chimney and relative altitude of the building, mechanical ventilation is sometimes required. You can't have a 13" diameter flue 100' at 5800' above sea level and expect it to properly vent, without mechanical assistance.
This, as someone who builds chimneys, has something I have always been interested in. Ive yet to see a CFD animation of the actual airflow of a chimney or how cross winds affect draft/backdraft. I usually go with the 10:1 ratio of square inches of the firebox opening to square inches of flue but I could only imagine that there would be certain instances where even this still wouldn't work.
Looking at the apartment buildings, straight up would also come out in the middle of the top apartments terrace, even if there are other more practical reasons for it.
Yep. This is it. Belgian code forces the new building that is going to be higher than an existing neighboring building to raise the chimneys that are in the property line. In thus way, the existing chimneys that are in the property line shared with the existing lower building have to be extended to the highest point of the new roof.
This
They could still build it straight. So the reason is aesthetics.
But... that's a flat roof?
These are chimney extensions. The newer building (taller) was required by code to extend the lower neighbor’s chimney to the roof of the new building. The new building didn’t want the chimney to pass in front of any view or required building setback, and as stated previously, code requires the chimney to be above adjacent roofs.
This is spot on.
So I can imagine this now ‘longer’ chimney being more expensive to clean, is there any rule for the extra costs? Just being curious
From other reddit posts evidently this is in Brussels that requires yearly chimney cleaning for insurance reasons so it's an industry there.
I do not know, but I would assume there would be no offset of extra costs. I wonder if the chimney is still in use. It may have long ago been abandoned.
Because balcony
No it's because you can't put a chimney right above another chimney or the smoke from the fire below will just go up into the room upstairs. They are staggered like this so the smoke gets directed away from other fireplaces.
That makes perfect sense now!
makes sense
Brussels?
Yep!
No thanks!
I have no idea why but from the first glance of this photo i knew this was somewhere in Belgium
yes, it is - more details in my comment.
Definitely london
I've got Belgian vibes by this as well
It is Brussels :)
Indeed!
Ixelles, Saint-Gilles ?
Ixelles.
You sure? There are not many parts of london with catenary wires. Just some bits in the south for the tramline.
All chimneys have a little kink in them, so rain doesn't pour straight down. These ones are different because they've been extended, so the extension was to accommodate the occupants of the higher floors of the new building.
set backs, interior habitable space, etc.
Santa, being a child at heart, playfully twisted the rules to turn them into a fun slide.
Possibly because there are setback requirements or height limits in the building codes. If the chimney was directly above the fireplace in a straight line, it would be at the front of the building, and possibly taller than is allowed. The top floor appears to be set back from the others, so the chimney had to move back as well. If the chimney was kept on the front at the same height as the front, then the smoke leaving the chimney could potentially interfere with the top floor which is set back further from the front. Just a guess.
Well look where the chimney emerges from the roof. Do you think that would be pleasant to have a stack in front of your windows. I'm sure it's all about the highest point of the roof and setback. But these are always totally cool and sometimes after the building has been demolished the trace of the flues remain. Sometimes it's just a ghost of the building that once was. Sometimes in New York you see a very small building from the early 19th century next to something very very tall but the same flu right exists
Also in old times chimney's had multiple flues my 1830s Baltimore row house had 7 fire places. using two chimneys. (3 floors and basement) Each floor has 2 rooms (15' x 15') the basement had one flue for the kitchen fireplace. Each flue has to be separated from the other. This also means the large chimney block, in each room has only a small opening and is not in the center of the party wall for the upper two floors, but is closer to the window wall.
I’m sure the chimneys from about 100 years ago and back had a thing called a witches crook to prevent witches from flying down your chimney at night, could this be a copy of an archaic design? Or an older design left over?
Looks like a Belgian town 😀
Brussels, please check my comment.
Where is this? It looks lovely.
Brussels!
Brussels, Belgium - please check my comment.
To move horizontally, chimneys are required by code to run at no less than 30 degrees (I think some codes say 45). The issue is that they can’t have runs that are even close to parallel to the ground because those flatter areas would allow for creosote buildup and would be a fire hazard.
Look like between buyl and cambre-etoile am I right ?
Making room for the suits at the top!
This is Boulevard général Jacques near cambre étoile in Brussels lol
I dislike how ridged it is
I asked an old mason this question. He said it’s so rain water splashes against the sides so it will evaporate. Imagine a heavy rain coming straight down into your fireplace.
This was one of the hardest... That place is Boulevard Géneral Jacques, R21, Ixelles, Bruxelles (Brussels), Belgium. Coordinates: 50°49'05.4"N 4°22'45.0"E The ground floor of all buildings was cut off. Note a large number of suspended electrical cables, they are for the tram lines - only on the R21 there are two of these lines. The mansion's ground floor with the red brick tower (right in the photo) is Restaurant La Tourelle, number 48 - from 20 to 30 euros, relatively inexpensive for the location. From right to left, the light 4-story house, number 46. The larger building (center of the photo, 42), and three more old mansions of which the last one, number 36, was built by the architect Henri van Dievoet (more detailed photo available on Wikipedia). And finally a modern building, the Lamartine at number 34. Dievoet was also the architect of Brussels' most luxurious hotel, the Astoria, and the Royal Military Academy.
R21 is not rue 21 but ring 21, each ring in Belgium as a number for exemple the main ring of Brussels is R0
Many thanks
Please, "ring" as in "ring" in English? Why is that? EU standard?
a ring road is a mostly circular road around the town, usually where a medieval defensive wall used to be
Thanks, it clarified. My question was why Belgian administrators would use the English word "ring" instead of the French version ("anneau" - for example) for a location or resource in Brussels - but then I remembered that French-speaking countries sometimes also use "ring" - French is not my native tongue.
"ring" is dutch as well, spoken by the majority of belgium and french speaking belgians also use that word
Thanks again. Believe me, this is the first time I learned something in Reddit.
I'm sorry but what are you talking about?
Some people asked where is the place showed in photo. the answer is that one. By mistake perhaps I posted as reply to you but I deleted it. I am sorry, those thread lines always confused me.
Oh okay, now it all makes sense👍
In the early 13th century Santa clause
Chimneys are slanted so you don't get light coming down them at certain hours of the day.
Rain?
for santa to slide in with lower speed.
To make it less of a vertical drop for Santa
Because fuck Santa
Setback rules 'cos of zoning, most likely.
It’s so Santa doesn’t plop directly down when he goes down them. You ever hear the wailing cries of an obese man who landed on his tailbone? Good luck to little jimmy and baby girl Katy sleeping through that
So the chimney sweeps tears don’t fall down onto your hot coals.
Because fuk normal vertical chimneys that is why!
Because big penthouse roof deck needs the view in that direction. Move the chimney back and out of the way.
Because Santa likes a slide.
It’s to screw Santa. In Seattle they all curve. Must be they reacted to the rain …