I am running black pipe from a wood stove into a masonry chimney. I have about 6-8 inches of clearance from the foundation beam where it goes into the chimney. Will I have to use black double walled in this area ?????
Double wall black pipe distance from Wood floor ????????
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babalu87
New Member
Use double wall, over time the wood changes chemically when heated and cooled then its flash point becomes much lower.
Technical terms to follow , just not from me
Technical terms to follow , just not from me
The celarance is usually listed by the manufacturer but most of the double wall connector pipe carries 6" clearance to combustiables
Gunner
New Member
babalu87 said:Use double wall, over time the wood changes chemically when heated and cooled then its flash point becomes much lower.
Technical terms to follow , just not from me
Pyrolysis
Thank You for your kind replies.
Ok Double wall pipe it is. Now I have some another questions.
The 6 inch hole that goes from the house side into the clay liner of the chimney is about 4 inches thick from the inside in the house to the inside of the chimney liner. So.
1.Do I need to get the pipe all the way into the liner or jsut part way into it???
2. I ask because the opening is 6 inches but very very tight and I can basically only get the crimped end of a piece of single wall into it and then I would have to pound that in farther if I were going to get it all the way into the liner. Problem is that I dont think the crimped end is supposed to go in there... is it??? My manual says the crimpled ends are to go closest to the stove or doesn't it matter???
3. Can standard black double walled pipe be cut to shorter lengths as I need about 18 inches???
4 If I use an adjustable double wall piece can I break it if I pound on it to get it into the opening??
Thanks for your help guys.
Ok Double wall pipe it is. Now I have some another questions.
The 6 inch hole that goes from the house side into the clay liner of the chimney is about 4 inches thick from the inside in the house to the inside of the chimney liner. So.
1.Do I need to get the pipe all the way into the liner or jsut part way into it???
2. I ask because the opening is 6 inches but very very tight and I can basically only get the crimped end of a piece of single wall into it and then I would have to pound that in farther if I were going to get it all the way into the liner. Problem is that I dont think the crimped end is supposed to go in there... is it??? My manual says the crimpled ends are to go closest to the stove or doesn't it matter???
3. Can standard black double walled pipe be cut to shorter lengths as I need about 18 inches???
4 If I use an adjustable double wall piece can I break it if I pound on it to get it into the opening??
Thanks for your help guys.
Gooserider
Mod Emeritus
Upnorth765 said:
Describe the hole a bit - what is the chimney made of? What is the hole like, is it lined with a metal sleeve?
Elk can answer better, but my understanding is that the ideal is to have the pipe sticking in far enough that it is just flush with the liner.
The idea on crimps is that you can potentially have liquid creosote condensing on the walls of the flue, and dribbling back down the insides of the pipe. You want to arrange the crimps so that you are directing the creosote that runs down the inside of each section into the inside of the next peice of pipe. You could think of it as being like stacking a bunch of funnels.
Check the manual on the pipe you are planning to use. I know it is OK to cut single wall, but I don't think you can cut most double wall pipe.
Probably.... I've found that unless something is designed for it, pounding is usually a bad idea unless you are gentle and know exactly what you are doing. :red:
I would check with the makers of the pipe in question, I think you can get a special adapter pipe that is intended for EXACTLY the application you are talking about. I know you can get single wall that is slightly undersized specifically to go into thimbles, I think they make something similar for doublewall.
Gooserider
quote
Describe the hole a bit - what is the chimney made of? What is the hole like, is it lined with a metal sleeve?
Thanks for the reply.
Ok.. is Thimble the technical term for the 6 inch hole going into the chimney from the house?
It is bacically concrete hole, no metal sleeve,its 6 inches and it goes into the chimney which is a cement block type chimney with a clay liner. It had a fuel oil furnace in it previously.
1. Maybe I could pound a piece of single wall 6 inch the hole and then leave a couple inches sticking out to mount the double wall piece to ???
Describe the hole a bit - what is the chimney made of? What is the hole like, is it lined with a metal sleeve?
Thanks for the reply.
Ok.. is Thimble the technical term for the 6 inch hole going into the chimney from the house?
It is bacically concrete hole, no metal sleeve,its 6 inches and it goes into the chimney which is a cement block type chimney with a clay liner. It had a fuel oil furnace in it previously.
1. Maybe I could pound a piece of single wall 6 inch the hole and then leave a couple inches sticking out to mount the double wall piece to ???
bacsales
New Member
If you are using Selkirk Metalbestos the part # is
6ds ma
6 for 6" flue
ds for double wall Smoke pipe
ma for Masonary Adapter.
Look for it at selkirkinc.com under hearth then ds smokepipe.
6ds ma
6 for 6" flue
ds for double wall Smoke pipe
ma for Masonary Adapter.
Look for it at selkirkinc.com under hearth then ds smokepipe.
Corie
Minister of Fire
Yeah, and the DSP setup is particularly sharp imo. I've used it before with much success.
Also, as was asked above, make sure that the metal pipe going into the masonry chimney is flush with the interior of the flue tile. If you extend the metal adapter into the flue, you will cause excess friction to the flow at that point.
Also, make sure you seal around the metal masonary adapter and screw it to the masonry chimney.
Also, as was asked above, make sure that the metal pipe going into the masonry chimney is flush with the interior of the flue tile. If you extend the metal adapter into the flue, you will cause excess friction to the flow at that point.
Also, make sure you seal around the metal masonary adapter and screw it to the masonry chimney.
Hokerer
Member
Also, what's the normal (or the actual in this case) size flue for a fuel oil furnace? That is, is he going to have a problem with the existing clay lined chimney being either too small or too large (more likely, I guess) and maybe need a liner?
Thanks for the replies. I believe my clay liner is six inch.
Do I need the special adapter or can i just use single wall pipe going from the inside of the liner into the house a couple of inches and then the douple wall will slide over that so it will all be double wall inside the house except for the little bit that is inside the masonry. hate to buy a special adapter that does the same thing and I know my local stores dont have them.
Thanks
Do I need the special adapter or can i just use single wall pipe going from the inside of the liner into the house a couple of inches and then the douple wall will slide over that so it will all be double wall inside the house except for the little bit that is inside the masonry. hate to buy a special adapter that does the same thing and I know my local stores dont have them.
Thanks
Gooserider
Mod Emeritus
Upnorth765 said:
No, a thimble is a metal or other material sleeve that lines the hole in some chimneys. You just have a plain hole with no thimble, so in theory you could make the hole a bit larger without to much difficulty if that was the only option. When you have a metal thimble, then you can't do anything to enlarge the hole as easily because that would destroy the thimble... OTOH, the thimble acts to line the hole so it is a little easier to get away with a pipe that doesn't exactly line up with the edge of the flue tile.
Have you had the chimney and flue inspected and cleaned by a sweep or other trained person? A woodstove has a different set of requirements than an oil furnace, so you need an inspection to make sure that the chimney is in good shape and suitable for a wood stove - just because it worked with the oil furnace does NOT mean it will work with a stove!
Sizewise, a 6" square or round clay tile should be fine for most stoves (though there are a few that require an 8" flue) but you need to verify that the tiles are still in good shape physically.
In terms of your idea about hammering a peice of single wall pipe into the hole with a bit sticking out to fasten onto, that is NOT a good idea. Excessive hammering on a chimney could damage it internally, including cracking the clay liner tiles. Even if you got the peice into the hole, it would not be compliant with any codes, which means you would fail any permit inspections (assuming the inspector does a proper job, and that you pulled a permit in the first place) and also, more importantly, could be grounds for your insurance co. to deny coverage if you ever had a fire. Code explicitly says that once you have gone from single wall pipe to double wall, you may NOT go back to single wall for any reason.
If your dealer doesn't stock the masonry adapter, he should be able to get it for you, or there are plenty of places you can get one online. The cost isn't that outrageous and it's worth it to do the job right and not take chances with your safety. As I've said elsewhere, we aren't the "stove police" and we won't drop a dime on you if you don't do things per code; but we all think safety is the top priority and will urge you to do things right and to code because we care about your safety.
Gooserider
a thimble is required code wise I can not advise a way that is not code compliant. Single wall can be used prior to the clearance issues styarting from the stove flue collar
what if you did it this way using a tee to make the 90 drgree bend, single wall from the flue collar to a double wall tee you could use single wall within the conceret area.
to the begining of the clay flue the flue extend enough single wall outside the thimble 1.5" to make the connection with the double wall pipe running from double wall tee. that double wall would have to recieve the 1.5" single wall overlap and the dobble wall resting tight against the masonry chimney witha bead of defractory cement to seal the double wall to the masonry chimney
what if you did it this way using a tee to make the 90 drgree bend, single wall from the flue collar to a double wall tee you could use single wall within the conceret area.
to the begining of the clay flue the flue extend enough single wall outside the thimble 1.5" to make the connection with the double wall pipe running from double wall tee. that double wall would have to recieve the 1.5" single wall overlap and the dobble wall resting tight against the masonry chimney witha bead of defractory cement to seal the double wall to the masonry chimney
Quote ...A thimble is required code wise.
Thanks for the replies. I want this safe.
1. So then what exactly constitutes a thimble? If i take a piece of black singe wall and put it in the hole flush with the liner and leave an 1.5 of the crimped end sticking into the house. Is this a considered a thimble?
2. Then attach 12 inches of double walled pipe on that would that meet code??? It would meet my insurance inspectors code probably wouldn't it?
3. Do I need the masonary adapter as well with this set up or not?
4. Are you saying If I put double wall for 12 inches at the chimney I have to continue woth double walled all the way to the stove too??
Thanks guys
Thanks for the replies. I want this safe.
1. So then what exactly constitutes a thimble? If i take a piece of black singe wall and put it in the hole flush with the liner and leave an 1.5 of the crimped end sticking into the house. Is this a considered a thimble?
2. Then attach 12 inches of double walled pipe on that would that meet code??? It would meet my insurance inspectors code probably wouldn't it?
3. Do I need the masonary adapter as well with this set up or not?
4. Are you saying If I put double wall for 12 inches at the chimney I have to continue woth double walled all the way to the stove too??
Thanks guys
Gooserider
Mod Emeritus
Upnorth765 said:
Elk is our unofficial Hearth.com code guru
in his life offline he is a real official gov't type building inspector, and has trained a good many of the inspectors in MA. I occasionally have philosopical arguments with him about the merits of having to get the gov'ts permission to do things to our own property, but have no doubts about his personal competence. He has helped lots of people here get things done right, including getting botched "professional" installs redone to meet code...I will defer to Elk on the official definition of a "thimble" if he says that is what it takes to meet code, I'm sure he is right. I always thought a thimble was the metal sleeve I described earlier, but Elk is the one with the code reference books.
It should, but with insurance co's there is no guarantee. However if there were a problem with the insurance inspector, I expect Elk would be able to point them at the exact chapter and verse of the NFPA or other relevant national code saying that what he recomended was OK. The codes are complex, and sometimes not all inspectors know all the ins and outs, so sometimes code cites are needed to make them happy.
From what Elk says, perhaps not, but he will need to spell that out better - sometimes he is a bit hard to follow - we keep trying to tell him about spell checkers, but he doesn't always listen %-P
Perhaps I'm misunderstanding something myself, but my understanding was that it's the other way around - you can have a limited amount of single wall between the stove and the start of the double wall, but once you hit the double wall, you can't go back to single. I was sort of confused when Elk was suggesting using a peice of single wall inside the chimney to make the connection for the double wall, but that may be an exemption.
It might help if you can post some pictures of your setup, including the chimney and hole, along with the beam you are trying to work around, etc.
Another option that MIGHT be possible, I'm not sure if it would give you the clearance reduction you need, is that they make heat shields for single wall pipe that will allow single wall to run closer to combustibles than the normal requirement. IFF you can use the heat shields to meet the clearances then it might be possible to do the entire run in single wall, which might be simpler than the double wall hookup.
Gooserider
Thank You guys for taking the time to reply. I don't know where else I would get this honest info to keep my family safe. Seems like everyone is always trying to sell me something. I got some photos of my situation. This photo is from my basement looking into the area where the pipe will go into the chimney. The problem I have is there is only 5inches from the top the thimble hole to the bottom of the wooden foundation beam above. So I thought I could put a concrete paver across the top and cement it in there nicely to block off the beam. I would like you ideas and opinion on this??? Would it meet code?? Thanks
my suggestion is to block in that opening with bricks and mortar and cut another opening lower install a metal glavanized thimble and not get
into the clearance issue at all.
into the clearance issue at all.
babalu87
New Member
Thanks for the replies.
1. How could I use bricks and mortar?? The top of that opening is about 17 inches across ??
or if you mean block in the entire opening and make a completely new one below that.. I think would be to low as well as i would have no upward angle for the pipe. The stove sits about 5 feet off to the side because of a LP furnace is right in front of the hole in the photo.
2. What do you mean cut it lower?? How much lower? the bottom of the liner is just a few inches downward?? Would a few inches realy make much difference.
How would I make a nice round hole for the thimble again.
3. Is there some sort of heat protection I could put on the wood around that area?? What? and where could I get some?
Appreciate you replies.
1. How could I use bricks and mortar?? The top of that opening is about 17 inches across ??
or if you mean block in the entire opening and make a completely new one below that.. I think would be to low as well as i would have no upward angle for the pipe. The stove sits about 5 feet off to the side because of a LP furnace is right in front of the hole in the photo.
2. What do you mean cut it lower?? How much lower? the bottom of the liner is just a few inches downward?? Would a few inches realy make much difference.
How would I make a nice round hole for the thimble again.
3. Is there some sort of heat protection I could put on the wood around that area?? What? and where could I get some?
Appreciate you replies.
Gooserider
Mod Emeritus
Houston - it sounds like we have problems...
1. Using a block to close off the beam as you were asking about would NOT be legal or safe! combustibles behind concrete are still combustibles, and have the same clearance restrictions and limitations. All bricking over the beam would accomplish is to hide the heat damage until you actually had a fire. (This might take a long time - the problem is that wood exposed to high temperatures for a long time undergoes a chemical change known as "pyrolysis" that causes it to change it's composition to one with a much lower combustion point. Thus it is possible to have an unsafe install that runs fine for many years, then goes "poof" one night and burns the place down with no warning, and without any change in what people had been doing) There are also no code recognized chemicals or other "magic potions" that will make wood less combustible. There really is no replacement for acceptable clearances.
Clearances can be reduced with double wall pipe, and sometimes by using properly designed METAL heat shields, but I'm not sure if there are ANY combinations that will let you get away with the situation as it is. There are limits on how close you can get with ANY combination of heat shielding techniques.
(ELK, before I suggest it, what about using several layers of Micore or Durock instead of the brick to create a sort of upside down floor protector? Would that possibly be a way around this if there was a "non-combustible, insulating wall" between the beam and the pipe?)
I would also agree with Elks suggestion which is to use bricks and mortar to stop up the existing opening, and cut a new opening in the chimney farther down so as to get adequate clearances. This is probably outside the usual "DIY" skillset, but should be no problem for a decent mason with the right tools and skillset.
However this brings up another BIG issue....
2. You just said that lowering the hole would be a problem because: "The stove sits about 5 feet off to the side because of a LP furnace is right in front of the hole in the photo." This raises several possible code issues!
Where is the LP furnace exhaust vented? Remember that it is NOT LEGAL OR SAFE to share a flue between appliances! So where does the furnace vent?
Where does the LP furnace get it's intake air from? There are very strong code restrictions on fuel burning appliances sharing the same space, largely because they should not "fight" over the combustion air supply. Unless one or both appliances gets it's air from the outside, having a furnace and a stove in the same room is usually a big "RED FLAG" issue - unsafe unless proven otherwise. The reason is that if the fresh combustion air supply isn't adequate for both appliances you can have severe malfunction problems at best, and at worst one appliance will pull it's air supply from the exhaust of the other, introducing a major Carbon Monoxide hazard.
Another issue is that it is not good to have long horizontal pipe runs
Gooserider
1. Using a block to close off the beam as you were asking about would NOT be legal or safe! combustibles behind concrete are still combustibles, and have the same clearance restrictions and limitations. All bricking over the beam would accomplish is to hide the heat damage until you actually had a fire. (This might take a long time - the problem is that wood exposed to high temperatures for a long time undergoes a chemical change known as "pyrolysis" that causes it to change it's composition to one with a much lower combustion point. Thus it is possible to have an unsafe install that runs fine for many years, then goes "poof" one night and burns the place down with no warning, and without any change in what people had been doing) There are also no code recognized chemicals or other "magic potions" that will make wood less combustible. There really is no replacement for acceptable clearances.
Clearances can be reduced with double wall pipe, and sometimes by using properly designed METAL heat shields, but I'm not sure if there are ANY combinations that will let you get away with the situation as it is. There are limits on how close you can get with ANY combination of heat shielding techniques.
(ELK, before I suggest it, what about using several layers of Micore or Durock instead of the brick to create a sort of upside down floor protector? Would that possibly be a way around this if there was a "non-combustible, insulating wall" between the beam and the pipe?)
I would also agree with Elks suggestion which is to use bricks and mortar to stop up the existing opening, and cut a new opening in the chimney farther down so as to get adequate clearances. This is probably outside the usual "DIY" skillset, but should be no problem for a decent mason with the right tools and skillset.
However this brings up another BIG issue....
2. You just said that lowering the hole would be a problem because: "The stove sits about 5 feet off to the side because of a LP furnace is right in front of the hole in the photo." This raises several possible code issues!
Where is the LP furnace exhaust vented? Remember that it is NOT LEGAL OR SAFE to share a flue between appliances! So where does the furnace vent?
Where does the LP furnace get it's intake air from? There are very strong code restrictions on fuel burning appliances sharing the same space, largely because they should not "fight" over the combustion air supply. Unless one or both appliances gets it's air from the outside, having a furnace and a stove in the same room is usually a big "RED FLAG" issue - unsafe unless proven otherwise. The reason is that if the fresh combustion air supply isn't adequate for both appliances you can have severe malfunction problems at best, and at worst one appliance will pull it's air supply from the exhaust of the other, introducing a major Carbon Monoxide hazard.
Another issue is that it is not good to have long horizontal pipe runs
Gooserider
Thanks for taking the time to reply guys!
Here is a photo of the new LP furnace along with the england so you can see the positoning. As you can see the furnace pvc pipes go to the right and outside. The air intake I believe is on the right also and goes upstair and to the attic? The chimney opening is directly behind the furnace in the photo.
Here is a photo of the new LP furnace along with the england so you can see the positoning. As you can see the furnace pvc pipes go to the right and outside. The air intake I believe is on the right also and goes upstair and to the attic? The chimney opening is directly behind the furnace in the photo.
Here is a photo of behind the stove to the chimney. I have the stove 19 inches off the furnace. and 21 inches off the back concrete wall. It is about a 4 1/2 -5 ft run to the chimney opening.
1. I could move the stove closer to the wall to get the pipe away from the furnace if that is better?
2. What is better to have the upward slant like it is or to come straight out the top of the stove then across to the opening. I would think the slant. Better flow and less heat up near the joists?
3. Back to the chimney opening problem. I thought putting the concrete "roof" between the beam and dBL pipe would solve the clearance issue. But it sounds like It would not.
What about cutting out some of the beam above the pipe. It an 8 inch beam ? Is it an option?
4. I like the idea goose had about building some sort of resistant box or something. How could that be done and with what???
If I had to lower the chimney I would scrap this project and take the stove back to HD.
HELP.....Ideas appreciated.
1. I could move the stove closer to the wall to get the pipe away from the furnace if that is better?
2. What is better to have the upward slant like it is or to come straight out the top of the stove then across to the opening. I would think the slant. Better flow and less heat up near the joists?
3. Back to the chimney opening problem. I thought putting the concrete "roof" between the beam and dBL pipe would solve the clearance issue. But it sounds like It would not.
What about cutting out some of the beam above the pipe. It an 8 inch beam ? Is it an option?
4. I like the idea goose had about building some sort of resistant box or something. How could that be done and with what???
If I had to lower the chimney I would scrap this project and take the stove back to HD.
HELP.....Ideas appreciated.
Roospike
New Member
Without rereading the whole thread again , why wouldn't a concrete thimble and double wall pipe put this issue to rest ? 6" to combustibles with the double wall pipe and the correct thimble and be done with it .
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