Chimney liner and insulation questions

[rdust]

I've been going back and forth on this for a while now and I'm running out of time so I need to get this done ASAP so I can stop beating this dead horse!

My question is about clearance to combustibles for the liner and insulation. My chimney currently has clay tiles(8x12 with some small cracks and some separations) that I don't want to remove for a 6" liner since it's a 26' or so chimney. I don't think an oval liner will work since the termination part of the oval is in the wide side which would point the stove pipe the wrong way and not thru the thimble. The chimney keeps a 2" clearance to my walls in the 2nd story and the wall the thimble is on in the family room is full masonry the width of the chimney which is a 3 flue chimney with the stove flue being the middle flue. I'm leaning towards using a 5.5" liner and not using insulation due to the chimney keeping a 2" clearance to combustibles through the house. Would this be up to code or will it require insulation even if my chimney has a 2" clearance to the walls? My other solution is to pour the insulation but doing this doesn't guarantee I won't have contact points between the liner and tiles at some point in the length of the chimney.

I don't have any fear of the house burning down in a chimney fire without insulation since it will still have clay tiles and it has a clearance to my combustible walls. It will need to be inspected by my township inspector before I can burn in it so it needs to be up to "code".

Questions, comments, suggestions and snide remarks are welcome.

 

[oconnor]

Snide remark - if it meets 2" clearance, how is it attached to the house??

Seriously though, The 2" is measured from the outside of the brick chimney, and I'm not sure how they actually build a brick flue that has 2" combustables clearance in a wood framed house.

As far as a 5.5 inch flue goes, I ran my insert with a 5 inch flue last year, and it did work, given my 23 foot central flue, but I did have to watch my technique a lot on reloads and startup to avoid smoke spillage. The main advantage of the insulation is going to be the speed of heating up during startup - better draft faster.

I'm not thinking you will have major problems with a 5.5 inch, assuming a central chimney.

 

[onesojourner]

I think you can probably get a 6 inch liner with insulation down a chimney with 8 inch tiles.

 

[rdust]

Snide remark - if it meets 2" clearance, how is it attached to the house??

Well I did lie, looking at the pictures refreshed my memory, I forgot I had some on my work pc. It is only connected to the house where the roof ties into in, it has a clearance to the walls. Attached a picture to help explain, I also understand what you mean, at some point my brick wall in my family room will touch a combustible surface even if it's 2' away from the chimney.

 

[rdust]

I think you can probably get a 6 inch liner with insulation down a chimney with 8 inch tiles.

8x12 outside, only 6.5x10.5 inside, probably not going to happen with insulation.

 

[oconnor]

Have you asked a local mason for a quote on having the tiles broken out - it isn't a hard job, but does need some specific tools. That would remove all doubt and maximise performance and safety.

I do also note the quote on the facing of your insulation.....

 

[rdust]

Have you asked a local mason for a quote on having the tiles broken out - it isn't a hard job, but does need some specific tools. That would remove all doubt and maximise performance and safety.

I do also note the quote on the facing of your insulation.....

I had it quoted for someone do do the full install and the price was out of this world. The mark up on parts alone was straight up silly. It's a tall chimney with a step roof and they wanted to knock an access hole in the wall in my family room to clean out the broken tiles. If it was only 15' tall it would be something I'd do on my own but being near 30' I'd rather not deal with it. I've seen plenty of people here using the 5.5 liners with success so I'm not worried about performance. Safety is obviously key but for the quoted price to do the job I'll just continue to run the furnace and not blink and eye.