Distance from clean out to exhaust pipe

[Stob]

This house has a Tremore wood stove into an 11''x7" chimney. But, in the basement, the flue was put in so low, the stove pipe goes into the chimney with no space for cleanout. They actually had to cut the 90 off the stove to get into the flue.

So, I want to cut ion a new flue above the stove, that will give room for debris to collect and use the old flue as a cleanout. So how high above the stove should the outlet pipe be? I was thinking a 3' section of vertical off the stove then a 90, the into the chimney. That should give planty of romm to clean out the soot from below the stack.

This OK or a different situation is needed?

Thanks.

 

[Mad Professor]

This house has a Tremore wood stove into an 11''x7" chimney. But, in the basement, the flue was put in so low, the stove pipe goes into the chimney with no space for cleanout. They actually had to cut the 90 off the stove to get into the flue.

So, I want to cut ion a new flue above the stove, that will give room for debris to collect and use the old flue as a cleanout. So how high above the stove should the outlet pipe be? I was thinking a 3' section of vertical off the stove then a 90, the into the chimney. That should give planty of romm to clean out the soot from below the stack.

This OK or a different situation is needed?

Thanks.

What you are describing is putting a new thimble into the flue to accept the stovepipe. 3' should be fine if the pipe has safe clearances from walls/ceiling.

At the bottom of the chimney/flue , install a clean out door.

Another thought, 11 X 7" flue in the chimney is going to be oversize for the stove and have less than optimal draft. Best solution would be install an insulated SS chimney liner with a T- that fits thimble.

 

[Stob]

Sorry I used the wrong term. And yes I would use the existing thimble as the clean out. As far as the size, so far it has drafted fine.

 

[Mad Professor]

Sorry I used the wrong term. And yes I would use the existing thimble as the clean out. As far as the size, so far it has drafted fine.

A thimble is not a clean out. A secure metal door

Proper draft depends on stove , flue/size not JUST where it goes into chimney, the flue , chimney height, and height above roof.

You contacted insurance agent about this? House burns down you might be SOFL!

 

[Stob]

Since this exchange several months ago, I have been researching the requirements, more specifically NFPA 211. They cover most everything about venting, chimneys, clearances, etc.

The cleanout has it's requirements, has to have 6-12" of space under the cleanout inside the chimney for debris collection. There is no requirement of what size, shape it has to be. Yes it has to have a metal locking door at the access point. This is easily done.

The chimney "connector" from the stove is the biggie. Lots of requirements here. Instead of 3 feet above the cleanout as I stated before will change to two feet, which falls within the height requirements. I will install a clay thimble for the stove pipe. and here the clearances comes into play. Seems like everyone in a business wants to push the manufactured system, but a clay thimble is allowed with an 18" clearance to any combustible for a through wall installation. Yes I have a drywall basement wall where the stove is, which has been removed, along with the wood framing floor to top of wall.

Once I get the thimble installed and the cleanout installed, the framing will go back as metal framing, and Durock will be used in place of drywall. Durock is a certified non-combustible and of course, metal studs isn't combustible. I'll do a thin plaster verneir finish over the Durock, and if it has a finish texture, I don't care.

I have the manufacture's clearances for the wood stove, floor, wall, ceiling and I'm good.

I think all of this will comply fully with the NFPA requirements. Coming from a commercial construction background, adhering to various code requirements is an everyday thing.

 

[Stob]

I read all I could find about cutting a hole in a clay chimney liner without it breaking all to pieces. I had to cut a round hole into the side of the 11x7 liner that is at least 8-1/2 to 9" diameter to accept the new thimble. I cut through the basement 8" block wall and the side of the chimney block to expose the liner. I located a joint in the liners where they were layed together, which were the same as a block course, and used this joint as my entrance point. I drilled out the mortar to get the blade in.

I used a Milwaukee diamond sawzall blade called "The Torch". It is a 1" high blade to make it easier for one to make a straight cut, but was not good for me since I had cut cut a curve. It also cuts a narrow kerf. So I cut the length of the blade down to 1/2" high with an abrasive wheel on an angle grinder. I marked out my hole and went at it. It cut but was very slow. The next day, I set up a garden pump-up sprayer with water and had a small flow of water trained on my cut, and what a difference! It kept the dust down, kept the blade cool, and it cut great. Without the water, it would have taken me a couple days, but with the flow of water I did the cut in a couple hours. I cut the thimble to the length I wanted it with the angle grinder and diamond wheel, set the thimble in place and held in position, ready to mud in the gap between the thimble and liner with refractory cement.

Thought this might help someone down the road.