Existing clay pipe wood stove connection question

[Rockhound]

The wood stove connection in my basement is an 8” round clay pipe flue which is run sloped horizontally through the 12”concrete block basement wall (extends a few inches through wall into space). Beyond this it goes to a rectangular clay liner chimney of all concrete block construction on the outside of the home. The exterior of the block is rock veneered.The previous owner left the stove connection pipe which consists of an 8” black single wall metal pipe elbow and straight section. It appears the elbow fits into the clay pipe flue with the straight section going vertically to the stove (I am only assuming though). I am wondering if there is a requirement for the metal pipe to be secured by some means to the clay flue. The slip fit is good and I imagine when the metal heats it will expand making the fit even better. Evidently the system was used for several years with no issues. The original home owner also stated he had no issues with creosote build-up in the chimney (he is menonite and constructed the home). Is there a clamp, etc. that can be used for the metal to clay connection? Are there any concerns with this system?

 

[begreen]

First concern would be whether there is any deterioration of the clay tiles in the chimney. Second concern would be that the chimney tile area is oversized for the stove you may want to connect to it. The previous owner may have had an inefficient old stove connected to it that wasted a lot of heat up the flue. Modern stoves can have lower flue temps and most want to have a 6"r flue (~28 sq in) and equivalent area chimney.

 

[Rockhound]

The wood stove connection in my basement is an 8” round clay pipe flue which is run sloped horizontally through the 12”concrete block basement wall (extends a few inches through wall into space). Beyond this it goes to a rectangular clay liner chimney of all concrete block construction on the outside of the home. The exterior of the block is rock veneered.The previous owner left the stove connection pipe which consists of an 8” black single wall metal pipe elbow and straight section. It appears the elbow fits into the clay pipe flue with the straight section going vertically to the stove (I am only assuming though). I am wondering if there is a requirement for the metal pipe to be secured by some means to the clay flue. The slip fit is good and I imagine when the metal heats it will expand making the fit even better. Evidently the system was used for several years with no issues. The original home owner also stated he had no issues with creosote build-up in the chimney (he is menonite and constructed the home). Is there a clamp, etc. that can be used for the metal to clay connection? Are there any concerns with this system?

Been spending some time reading through the forum so thought I would add some info. The block chimney actually extends below grade to the basement. I have been told but have not moved my junk out of the way that there is an inspection/cleanout door below the stove connection in the basement. I have not purchased a stove yet so I am in research mode looking at what I will need to do. Since the stove is going in a utility space I am not looking for anything fancy just a safe durable unit-no frills. The Buck Stove Plant is just up the road from me and they make a stove called the Little John. It kinda fits what I need and reading through the installation instructions the next thing I need to do is measure the existing rectangular flue somehow and make sure it meets the requirement that it can’t me no more than three times larger (area) than the stove connection. It is not huge so I may be good. The chimney does not touch the house except at the masonry wall and it looks like it has the required clearance to combustibles. Thoughts?

 

[begreen]

I don't believe Buck is allowed to sell the Little John anymore. It was an EPA exempt stove. Give them a call. It took a 6" flue, so it will be important to measure the tile size in the chimney. Preferably it is not more than 2x the sq area. 3x is pushing it.

 

[Nick Mystic]

I have a somewhat similar setup in the lower level of my home. I have a Woodstock Classic woodstove that has a rear exit with a 90 right at the stove. Then a single wall vertical pipe about 24" long going into another 90 with about 14" of single wall pipe that enters an 8" clay thimble. The 90s and the all the single wall pipe is 6". On the upper end of the horizontal 6" pipe that enters the 8" thimble there is some sort of connector that is 6" at the end of the pipe and then mushrooms out to 8" where it fits snuggly into the 8" clay thimble. The flue is is all 8" x 11" clay tile running about 28' up to the top. All of this is inside a very large centrally located chimney. You can see part of the 8' x 4' brick chimney in my avatar photo.

I've been running this system for the 15 years I've been in the home (it was here when we bought the house) with no problems. I have a good draft and the system burns very clean. I haven't had to sweep the chimney a single time, but I don't burn that stove more than a dozen or so times a season. When I pull the single wall pipe for my annual cleaning I usually scoop a cup of soot/ash out of the bottom of the clay flue that extends about a foot below the thimble.

 

[Rockhound]

I will check out the clay liner for cracks and such. The house was built in 2000. The only thing keeping me from getting a stove with an 8" connection is I really don't need that a big a stove and I cant find a basic stove with an 8" flue. Does anyone know of any other manufacturers who make a basic stove?
I don't mind going to a catalyst, I had one in my old house I sold. I just don't need anything pretty and fancy but I do want a current code compliant stove.
Nick Mystic - I live over in near Marion, NC probably not too far from you!

 

[Nick Mystic]

Rockhound,
I'm located just about four miles south of Exit 81 on I-40 off of Sugarhill Rd. I wouldn't shop around for a stove with an 8" vent opening unless you really want that large of a stove. For example, the Hearthstone Equinox has an 8" flue collar and it's a 4 cu. ft. stove and cost around $4300. They make adapters that will allow a six inch flue pipe connect to an 8" thimble. The one on my six inch pipe seems to have a good secure connection and I haven't had any issues with it in the past 15 years of service. It is just a friction fit connector and since there is tension on the 8" end of the connector it doesn't move around at all.

 

[Rockhound]

Almost close enough to smell your smoke. I am further south and probably closer to Lake Lure. I am down off of Cove Road. Yea don't need a big boy and my wallet is not that fat!

 

[HisTreeNut]

If you can get to Spruce Pine and the Buck factory, it is worth the look. The folks there are pretty helpful and you can see every stove they have available. Call ahead so they know your coming. We bought a 91NC which is more than you are looking for, and we are very pleased with it.
I am in Burnsville so as a crow flies, we're neighbors!

 

[Rockhound]

That's good to know about Buck. I would definitely like to see what I am buying. Did you buy direct from them or have to go through a dealer?
Got a couple acres up there in Yancey off of NC-80. They hit me hard with the new tax assessment so I am going to give them a fight. You definitely need a good stove up there where you are, much higher altitude!

 

[HisTreeNut]

I used a dealer/installer but I could have bought it direct. It was easier for me to go through the installer. I don't have a pick-up or trailer and the 91NC is over 600lbs.
The folks over at Buck do more than just wood stoves, and they have a few things the wifey is interested in. Fun place to visit.
The stove has been great so far. We have not had to turn the electric baseboard heat on at all and the house is warmer tho year than last year by far. The electric bill has been about 1/3 of what it was last year.
We just got our tax assessment also...ouch!

 

[Rockhound]

So I am still wondering about the connection to the clay pipe. I have been digging around. Do I need what they call a clay pot adapter and will this work with 4.5"inches of the 8" round clay flue being through the block basement wall. maybe I am wrong here but you don't want to fit the steel stove pipe into the clay liner you want it to fit over it correct? The situation I have is an 8" clay liner through a 12" basement block wall and then into a block chimney and then into a rectangular clay liner. All this stuff is below grade too.

 

[begreen]

The stove pipe goes inside the clay thimble.

 

[Rockhound]

Thanks. So the way it appears they were using it was correct and the stove pipe just slips in. I may very well have a professional company come out and do an inspection and do the install. I just want to make sure they know what they are doing and with the expertise on this forum it helps out a lot. I discovered another potential issue as a drywall ceiling was installed in the basement and it drops down in the area of my stove because of duct work. It only allows for 12" from the top of the clay liner to the ceiling and I think I need 18". I could remove the ceiling and wood frame supporting the dropdown in that area and have the metal ductwork exposed and then I would have the clearance but maybe there is another method out there or maybe I am just wrong about the clearance.

 

[begreen]

Correct, a minimum of 18" is needed from single wall pipe to any combustible, drywall included. One option would be to use double-wall stove pipe which needs 9" clearance to the ceiling.

 

[Rockhound]

OK Thanks. That may be a good option. I have used selkirk stainless before but may not need anything that fancy. Can I get double wall that will still slip into the round clay liner like the single wall? Sorry for all the questions but you seem to have the answers I need.

 

[bholler]

Yes you will need an adapter to do that but they make it. What are your goals with this stove? If you are planning on using it allot i would recommend a stainless liner to match the size of what ever stove you choose. But at the very least you need to have it inspected with a camera to check the condition.

 

[Rockhound]

I believe my flue size is 12"x 8" O.D. I don't know how flue linings are installed but there is no way to get into the chimney except from the top, from the 8" round stove connection or from a cleanout located below the stove connection which I have been told is there but need to move my junk to verify. In my mind I wonder how they could make the bend from the rectangular chimney into the 8" round clay liner stove connection with no access. It seems from what I have read you want to use an insulated liner correct and if I went 6" could it be done? The installation directions for the stove I am looking at says the chimney should not be greater than three times the area of the stove connection. I believe a 6" stove connection has an area of 28" and a 12"x 8" O.D. flue has an area of 67". This is definitely not an optimal situation I know but it does fall barely within the manufacturers requirement. I have asked the owner who ran his 6" stove and he said there was no problem with draft or creosote build-up. As far as my goals, hey if I have a stove I am going to use it while I am home but I probably would let it die down before I went to sleep. I appreciate everyone on here that is helping me so if anything I have said is off the wall let me know. You guys have really been a big help and I thank-you. I had an Appalachian Stove Gemini XL in my old house with Selkirk Stainless Chimney. Wish I could have taken it with me as it cost me a bundle so now I am starting from scratch again.

 

[bholler]

It can be installed but to fit in your chimney with insulation it would either need to be ovalized or the old clay would have to be removed. But to install it you use a 2 part tee which you drop down the chimney attached to the liner then you attach the tee snout which extends out into the room

 

[begreen]

If the clay thimble is 8" ID then 6" double-wall connector might fit in the thimble.

I believe my flue size is 12"x 8" O.D.... The installation directions for the stove I am looking at says the chimney should not be greater than three times the area of the stove connection. I believe a 6" stove connection has an area of 28" and a 12"x 8" O.D. flue has an area of 67".

Wouldn't the area be more like 77 sq in if 7" x 11" ID?

 

[Nick Mystic]

There is always an ideal way of doing things, but that doesn't mean that other ways won't also work. As I mentioned earlier, I have a very similar set up with my Woodstock Classic and it drafts just fine going into an 8" clay thimble that dumps into an 8" x 11" clay tile flue. You don't lose much by trying out such a set up to see if it meets your needs. If it works well for you then you save yourself quite a bit of money. If it doesn't work, then you can try other more expensive options. I always like to try the less expensive alternative first because if it works you can save a lot of hassle and money with little down side.

 

[bholler]

I agree with nick totally after having the chimney inspected by a pro for safety

 

[Rockhound]

Thanks guys,
To take out the round clay liner would be a bear as it is all below grade through my 12": block basement wall. I am pretty sure it is 8" I.D. on the clay but I will double check. The way they built the chimney it doesn't even touch my exterior wall all the way up. I will get it cleaned and inspected before I go forward. Appreciate all the help!

 

[bholler]

To take out the round clay liner would be a bear as it is all below grade through my 12": block basement wall.

Not any different than removing them from any other chimney