30degree bend in chimney

[Steve_Malta]

Dear All,
5 years ago I installed a fireplace. The chimney goes 2 storeys up until it reaches roof level. Due to planning constraints, I had to bend my chimney by 30 degrees rather than 45 degrees. All worked well and the draft is very strong. Recently my chimney got badly blocked, there was a huge amount of creosote. After cleaning it,
the fireplace worked perfectly again.
Do you think that the large amount of creosote is due to the sharp bends? Do you think that if I insulate the inclined section, I would get less creosote buildup?
please refer to photo.

thanks
Steve

 

[Hogwildz]

Dear All,
5 years ago I installed a fireplace. The chimney goes 2 storeys up until it reaches roof level. Due to planning constraints, I had to bend my chimney by 30 degrees rather than 45 degrees. All worked well and the draft is very strong. Recently my chimney got badly blocked, there was a huge amount of creosote. After cleaning it,
the fireplace worked perfectly again.
Do you think that the large amount of creosote is due to the sharp bends? Do you think that if I insulate the inclined section, I would get less creosote buildup?
please refer to photo.

thanks
Steve

Bends will slow draft, and that much uninstalled being outside, will surely cool the gases & collect creosote. Why not use insulated class A, and go straight up? What is the thought on running it out the roof, then over to the other chimney?

 

[begreen]

Creosote builds up when the flue gases get cool enough to condense inside the flue. This happens around 120ºC. The long diagonal run could be cooling off the flue gases, especially if it is uninsulated. And a very common cause of creosote buildup is too damp wood being burned. Firewood should be fully seasoned.

 

[Steve_Malta]

Bends will slow draft, and that much uninstalled being outside, will surely cool the gases & collect creosote. Why not use insulated class A, and go straight up? What is the thought on running it out the roof, then over to the other chimney?

Local building regulations require chimneys to be 14' away from facade and 5' away from side so I had no choice. I was not happy with the 30degree bends however when clean, the system works perfectly. I am considering adding insulation to the pipes at this stage.

 

[Steve_Malta]

Creosote builds up when the flue gases get cool enough to condense inside the flue. This happens around 120ºC. The long diagonal run could be cooling off the flue gases, especially if it is uninsulated. And a very common cause of creosote buildup is too damp wood being burned. Firewood should be fully seasoned.

The non-insulated section is worrying me and I am considering having it insulated.

 

[Steve_Malta]

Do you know whether wood creosote can be used as soil fertilizer? I found conflicting information on the web.

 

[begreen]

The non-insulated section is worrying me and I am considering having it insulated.

Here in the states that pipe would have to be insulated class A chimney pipe. Without insulation it is a fire and human safety hazard as well as a large heat loss.

 

[Steve_Malta]

Here in the states that pipe would have to be insulated class A chimney pipe. Without insulation it is a fire and human safety hazard as well as a large heat loss.

In my country, winters are not very cold and we have little awareness on these issues. Fireplaces are not so common. That s why I am asking on this forum. thanks for all your replies

 

[begreen]

Do you know whether wood creosote can be used as soil fertilizer? I found conflicting information on the web.

I would think that is a bad idea. It is a flammable, tar based fuel. You could just reburn it in small quantities at a time.

 

[Steve_Malta]

I would think that is a bad idea. It is a flammable, tar based fuel. You could just reburn it in small quantities at a time.

Is it toxic to plants and trees?

 

[begreen]

I'm not sure how one would insulate a single wall pipe and keep it weatherproof. It may need to be replaced. A poster here said that class A chimney pipe is available in Israel but I am not sure about Malta. Class A chimney pipe is a stainless steel pipe surrounded by an inch of insulation, then stainless steel jacket.

 

[Hogwildz]

If it were me, I would insulate it very, very well, (with proper insulation for this purpose)and build a chase of non combustible materials around it for a more appealing look. I would also leave it possible to open the chase and be able to get to the piping is the need arose. You may want to check &/or sweep it more times to avoid blockage.

As far as fertilizer, I cannot answer that. I have no knowledge of it. If you're worried about getting rid of the creosote, just put in in the stove and reburn it.

 

[Steve_Malta]

If it were me, I would insulate it very, very well, and build a chase of non combustible materials around it for a more appealing look. I would also leave it possible to open the chase and be able to get to the piping is the need arose. You may want to check &/or sweep it more times to avoid blockage.

As far as fertilizer, I cannot answer that. I have no knowledge of it. If you're worried about getting rid of the creosote, just put in in the stove and reburn it.

I think creosote burns with a white bad smelling smoke. I will talk to my supplier re insulation.

 

[Hogwildz]

If not imposing, would you share more photos of your home? Looks very interesting.

 

[begreen]

Is it toxic to plants and trees?

I don't know for sure. Like you I have read differing opinions on this topic. I don't put it in our garden, but our chimney produces very little creosote.

 

[Steve_Malta]

If not imposing, would you share more photos of your home? Looks very interesting.

section


bricks


cheers!

 

[Hogwildz]

View attachment 192810

Looks nice. Impressive viewing glass on that burner.

 

[Steve_Malta]

Looks nice. Impressive viewing glass on that burner.

 

[Hogwildz]

View attachment 192815

Wow, that is nice! I like the lights in the hearth.

 

[Steve_Malta]

Wow, that is nice! I like the lights in the hearth.

thanks,

so it seems you are more concerned about the lack of insulation rather than the 30degree bends? am i understanding you?

 

[Hogwildz]

thanks,

so it seems you are more concerned about the lack of insulation rather than the 30degree bends? am i understanding you?

Yes, lack of insulation is allowing the exhaust gases to cool down to much too fast, which will create creosote problems. Did you find out what area was clogged? I am guessing it was the exposed piping area outside the roofline? Insulating well should help a lot. I would still check every month or so after insulating, just to get an idea of how it performs with the insulation and what the creo build up is like afterwards. This will give you a gauge of how often you should sweep the piping. You may also experience a stronger draft after insulation also.

 

[Steve_Malta]

Yes, lack of insulation is allowing the exhaust gases to cool down to much too fast, which will create creosote problems. Did you find out what area was clogged? I am guessing it was the exposed piping area outside the roofline? Insulating well should help a lot. I would still check every month or so after insulating, just to get an idea of how it performs with the insulation and what the creo build up is like afterwards. This will give you a gauge of how often you should sweep the piping. You may also experience a stronger draft after insulation also.

yes thats the exact location.
insulation then is the solution

thanks a lot

 

[bholler]

Is that bare stainless pipe running up through your house? If so what is the chase it is running inside of?

 

[bholler]

yes thats the exact location.
insulation then is the solution

thanks a lot

Insulation will help some but that is a very long run that is way to close to horizontal for my liking. There are many things that if it was here would make that install fail an inspection.

 

[Hogwildz]

He lives in Malta, who knows what code if any they require there. I may be wrong, but most housing there is concrete construction I believe.