Chimney Liner

[mu1166]

I'm a pretty newbie who is looking into getting a wood furnace. My exisiting brick chimney will need to be lined. The chimney is 9" square inside and has never had a liner in it. The mortar and brick look very good. The chimney runs through the center of the house. There are no bends in the chimney.

Do I need to get a dual wall chimney?

Single wall with some ceramic insulation?

etc...

I am looking for some opinions since I have never done this and would like to compare it with what the heating guy says when he come over to give me a quote. I might also be up to doing this myself if isn't to bad of a job.

Thanks in advance.

 

[swestall]

Wood furnace or wood stove: what type? If the liner will go into it, the size may be determined by the type of wood burning product that you install.
More please...

 

[mu1166]

It will be a wood furnace.

Of the furnaces that I have look at so far, most of the ones that would suit my purpose have a 6" flue. the furnaces with an 8" connector are usually rated for an area quite larger than i need.

I am planning on using a 6" flue, but entertain options for a 6 or 8".

Thanks

 

[swestall]

Once you select the furnace, and know the flue connector size, then you with that for it will give you the best drafting. Also, if your 9" is a straight shot down, the 6 inch will give you room for a nice insulation blanket. If an outside stack, then all the way, if inside, then at least the part that is above the roofline plus a foot or so in.

 

[mu1166]

Yes, the 9" is a straight shot down. Should I insulate the whole thing? Should I use dual wall for safety inside the masonry chimney? What type of pipe should I be looking for?

I am just hoping to get an idea of what to ask/look for when the heating guy decides to show up. The chimney extends 2'4" above my peak. It exits right at the peak of the roof. Does the stainless pipe need to extend out of the masonry chimney or is it ok to just run to the top of that and have the screen on it then?

this site has been extremely helpful.

Thanks for the replies.

 

[jtp10181]

It sounds like you have a block chimney with no clay tiles? In this case you MUST use an insulation wrap if you choose to install a SS flex liner. The other option would be to install a DuraLiner round 6" liner which is double wall with an insulation wrap between the walls.

 

[mu1166]

I actually have 2 chimneys in the house and neither of them have any sort of a liner in them. One is concrete block (added on to the south side of the house) and they other is a brick masonry chimney that goes up the center of the house. Both of the chimneys look excellent as far as build construction goes but both are missing any sort of liner.

I am not going to be lining the concrete block chimney at this time, to many other projects going on.

With the 9" square opening, which is the best way to go? I don't know if I need to go dual wall, rigid, flex, what kind of insulation, etc...

I'm just seeing what a few of you recommend, opinions etc to I have some soft of idea and don't feel completely dumb when the heat guy stops by.

Thanks for everything.

 

[jtp10181]

I basically just answered that above. Here is a little more info... The rigid will be more expensive but will be smooth inside and easier to clean. A SS flex liner you will have wrap with 1/2" of insulation. You use whatever insulation is from the same vendor or recommended for the liner being used. It is a ceramic fiber kaowool insulation usually, with foil on one side.

Any way you do it the liner needs to be insulated or meet UL 1777 by some other means since your chimney does not have a clay tile liner.

 

[fraxinus]

First check your building code. It's likely neither chimney is in compliance. Second, check on the availability of a poured in place liner in your area. Supaflu and Ahern (not sure about spelling on that one). In my view, poured liners have several important advantages over stainless steel ones and are price competitive.

 

[mu1166]

Yeah, I'm pretty sure that neither chimney is up to code at this time. I am going to line the one that I will be using, and not sure what i'll do with the other. We'll let time tell on that.

I didn't know that there were poured in place liners. Who knows if there is anyone around here that does them. I'm having a hell of a time finding somewhere to look at wood furnaces at, but that is besides the point.

If it is a stainless chimney I just have to make sure that it's insulated or do a poured in place new liner... decisions decisions.

I think the dual walled insulated rigid stainless is sounding the most appealing at the moment. The T at the bottom could be interesting getting in. How far below the T can the pipe extend before I plug it? If I plug the T I don't think I will be able to unplug it for cleanout purposes unless i extend it down farther. It is definently going to be a fun install, and a great learning experience if I do try it myself with the help of some friends.

 

[jtp10181]

Simpson pretty much told us you can extend the chimney below the Tee as far as you want.

So is the Tee going to be inside the block chimney and then go through a thimble into some double wall to the furnace?

 

[mu1166]

Yes, the Tee is going to be inside the brick masonry chimney (which should be a joy of installing). The thimble will hook up to that and from there I wasn't sure if i needed dual wall or single wall stove pipe. I will probabily end up going dual wall but I am going to have to verify my distances and see.


I was checking some clearances last night, and it looks like i am about 2" short on the on my distance to the rear of the furnace and I will be 34" (from side of wood furnace) from my fuse panel. I do have some room to slide my existing furnace to gaine some side clearance room but looks like I may have to do some insulating of the rear wall. The rear wall is unfinish stud wall (finished on other side of studs) and the side wall is clay block. Looking like it's going to be a tigher fit than i thought......

 

[jtp10181]

The Tee in the masonry is not that bad. You have to get the Tee with the removable snout. You just attached the straight peice to the liner and drop it down then the snout attaches with a band clamp. Pretty slick way to get it done.