I recently had a wood stove given to me my existing terracotta chimney needed lined so I figured I out that I needed a 6" liner which I purchased, I was planning on using a pour in type insulation due to my chimney opening only being 7x11 opening. My question is would 1/4" blanket be enough as far as insulation BC I believe I could get that down the existing chimney it'd be tight but would work, or are there any other options?
chimney liner insulation?
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Ok do you have the required clearances from the exterior of the chimney to any combustible materials? For an exterior chimney you need 1" for an interior one you need 2" If you dont have this you need 1/2" wrap or atleast 1" of pour in all the way around the liner to meet code. You can have the clay removed you can use an oval liner or downsize to a 5.5"
The chimney runs in the middle of the house not an exterior wall. Has the terracotta with brick around that. I could oval the 6" liner I have now but was trying not to if all possible. And as far as clearances? Is that measure from then outside of the ss liner to the existing chimney liner?
No that is from the outside of the chimney to anything combustible you would need 2" which almost no one has.
Even to use the pour in insulation there would still not be enough room BC you said an inch on all sides which if the liner is 6 and the chimney is 7 there only roughly 1/2 unless I oval the liner. As far as ovaling the liner would I get less draft from 6 ovaled pipe or 6 round to me I would think the same but I've heard mixed thoughts
I will have to look and see how they framed around the existing chimney if remember right it wasnt tight there had been a gap around it which may be a good thing. Wats the best pour in type insulation also?
You areright it will reduce the volume of the pipe and the draft. This is why we always break out the liners But as long as it is done right ovalizing can work fine
It is pretty rare that we see one with proper clearance. You should also check the instructions for your liner most of them say for wood if you dont insulate it voids the ul listing and many times the warantee as well
Yea it does which I'm going to insulate just trying to plan wat I need to do whether it be try and break out the existing clay or ovaling the pipe. To me busting out the existing sounds the best way but also more time consuming and pain in the ass haha. I've got roughly 20 ft to break out.
I would not recommend it as a diy job It is not easy with out the right equipment and even with the right stuff if you dont know what you are doing you can do allot of damage in a hurry
Lockpicker
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If that chimney is masonry with a terracotta liner I would not attempt to bust out the liner to put in pour in n insulation. If the masonry is in good shape and you say it is an interior chimney drop some stainless flex down. You don't need insulation.
According to code manufactures instructions and ul listings you are wrong insulation is necessary
Lockpicker
Member
What code would that be. Is there a National (NFPA) code or does every township/county/ borough have its own set of parameters when it comes to flue installations? Is there a statewide requirement? I know NFPA changes the book on sprinkler and alarm systems on an almost weekly basis, so maybe something has changed, but last I knew there was no national code for flue installations. Besides NFPA is a private organization that makes recommendations they don't make laws. According to my brand new Kodiak instructions pages 37 through 39. I could just slide my insert in with no liner at all, or with just a stub of pipe that goes above the damper. So much for manufactures installation instructions.
Not trying to be a horses rear end here, but It would be just plain foolish to rip the terracotta out of a perfectly good tight masonry chimney, no doubt doing damage just so a body can install insulation around a stainless liner especially with an indoor chimney. Not sure about anybody else but I have never seen terracotta, block or brick catch fire yet. Now if the masonry had gaps and was in bad shape then it might be another story.
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R1001.15 Chimney clearances. Any portion of a masonry chimney located in the interior of the building or within the exterior wall of the building shall have a minimumair space clearance to combustibles of 2 inches (51 mm). Chimneys located entirely outside the exterior walls of the building, including chimneys that pass through the soffit or cornice, shall have a minimum air space clearance of 1 inch (25.4 mm). The air space shall not be filled, except to provide fire blocking in accordance with Section R1001.16.
Exceptions:
1. Masonry chimneys equipped with a chimney lining system listed and labeled for use in chimneys in contact with combustibles in accordance with UL 1777 and installed in accordance with the manufacturers installation instructions are permitted to have combustible material in contact with their exterior surfaces.
2. When masonry chimneys are constructed as part of masonry or concrete walls, combustible materials shall not be in contact with the masonry or concrete wall less than 12 inches (306 mm) from the inside surface of the nearest flue lining.
3. Exposed combustible trim and the edges of sheathing materials, such as wood siding and flooring, shall be permitted to abut the masonry chimney side walls, in accordance with Figure R1001.15 provided such combustible trim or sheathing is a minimum of 12 inches (306 mm)from the inside surface of the nearest flue lining. Combustible material and trim shall not overlap the corners of the chimney by more than 1 inch (25.4
There are no liner systems that allow zeroclearance with out insulation so Does this answer your question? And there is no reason that the body of the chimney would be damaged is you know what you are doing. Also read the ul-1777 listing the liners are tested for wood with insulation which means that in order to keep that listing you need to insulate them with an approved ul listed chimney insulation
Lockpicker
Member
Question bholler. Do you condemn as unusable all open fireplace chimneys you clean that have a tile lining where you can't determine that there is a one inch clearance to combustibles?
I let the people know about The possible problem but if i am not modifying them i don't need to bring them up to code while if i put a liner in it needs to be to code. The same goes for a homeowner doing the work if you are putting a liner in it should be up to code. I am much less worried about it for open fireplaces than i am for wood stoves though. But to answer your question no i don't condemn any chimneys i let people know about potential problems and they can make the decision from there. There are a few situations where i will not work on a chimney at all like slammers i just don't want to have anything to do with something that is that much of a safety and liability problem.
Lock picker i see you are from pa and that code is out of irc which is not adopted in its entirety in pa but that chimney construction section is absolutely adopted and is code in pa and as far as i know the rest of the US if i am wrong let me know.
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