Need advise on installing liner w/ or w/o insulation

[Serdroid12]

I've been a long time lurker of this website and I've read countless hours on the type of install to have but I am just tired and on a dead-end on what I should do. Here's some info on my situation:

• Raised ranch / split level
• Live in Connecticut. Last year temperatures went down as low as -11 F, but average 10s/30s in Winter.
• Exterior Chimney about 24' in height.
• 6" x 10" ID clay liner = 60 sq in
• Bought Englander NC30 - 6" = 28.26 sq in area.
• Manual says liner must be at least # above, and AT MOST 2.5x # above = 70.65 sq in.
• Clay liner seems to be in good shape. I've been on the roof and inspected it (although I am not a professional, but it looks in good shape). Previous owners only used the fireplace a few times since 1969 when the house was built. the only thing I DID notice was a line going down one of the interior sides about 1.5 ft down from the top but that was all.
• Fireplace has damper about 6" opening, goes straight up, curves to the side around 45 deg angle, then straight up the remaining 20ish feet.

Now i've read threads on insulating or not, using oval liners, etc etc but I honestly just need to hear suggestions based on the facts given above.

Now considering the 60 sq in area of the clay liner is less than their "AT MOST" recommendation, do I need to get a liner (thinking of draft) given the height of the chimney?

If I get a liner - will this in 5 x 7.5 = 37.5 sq in work? https://www.firesidechimneysupply.c...reflex-316ti-006-rectangle-chimney-liner.html - Will the 1/2" insulation still make this fit inside that 6" restriction? do I even need insulation? What about https://www.firesidechimneysupply.com/fireflex-316ti-006-oval-chimney-liner.html 5 x 7.4 with or without insulation?

Thank you for reading!

 

[Ludlow]

We put uninsulated flex in both my Dad's and my sister's chimneys for inserts. Once up and going they were fine. Getting them up and going....took some doing. They got up to temp and drafting good in their own sweet time. And in certain barometric conditions they wouldnt draft at all. We weren't even told about insulating them back then.

 

[bholler]

The requirement for insulation on a liner is based on clearance to combustibles from the outside of the masonry chimney structure. For yours being an externam chimney you need 1" from the outside of that chimney to combustible materials. If you dont have this your chimney is not up to code and if you put a liner in it needs insulation. You will also see performance gains especially because it is an external chimney.

To fit insulation in your rectangle liner there are several options.

1. Which in your case i would not recomend is taking out the clay liners.

2. Oval liner this is what i would recomend. You can use a flex liner either site insulated or pre insulated. If the chimney is straight you can also look into duraliner which is a pre insulated rigid lining system with flex sections to get through the damper area.

3. Rectangle liner. I wouldnt go this rout. They cost more and dont flow as well as oval.

 

[Serdroid12]

For yours being an externam chimney you need 1" from the outside of that chimney to combustible materials.

What is referred to by "from the outside of that chimney"? I've been to the attic and roof, the chimney is completely outside (it's hugging the siding/wall). Is the "outside of the chimney" also the brick that's next to the siding?

For yours being an external chimney you need 1" from the outside of that chimney to combustible materials.

To fit insulation in your rectangle liner there are several options.

1. Which in your case i would not recommend is taking out the clay liners.

2. Oval liner this is what i would recommend. You can use a flex liner either site insulated or pre insulated. If the chimney is straight you can also look into duraliner which is a pre insulated rigid lining system with flex sections to get through the damper area.

3. Rectangle liner. I wouldn't go this rout. They cost more and dont flow as well as oval.

I spoke with Rockford before you posted and they didn't recommend the rectangle liner since it is no longer flex-ible anyway. IT goes straight down for about 18 feet, then there's the space of the smoke chamber. So the guy recommended breaking the clay tile to fit a regular 6" insulated flex liner. Without breaking the tile, and considering the inside dimension is 6x10" even the 5.5" wouldn't fit. I'd have to go with 5" maybe - but would this NOT be recommended for the 6" recommendation of the stove manufacturer?

 

[bholler]

What is referred to by "from the outside of that chimney"? I've been to the attic and roof, the chimney is completely outside (it's hugging the siding/wall). Is the "outside of the chimney" also the brick that's next to the siding?



I spoke with Rockford before you posted and they didn't recommend the rectangle liner since it is no longer flex-ible anyway. IT goes straight down for about 18 feet, then there's the space of the smoke chamber. So the guy recommended breaking the clay tile to fit a regular 6" insulated flex liner. Without breaking the tile, and considering the inside dimension is 6x10" even the 5.5" wouldn't fit. I'd have to go with 5" maybe - but would this NOT be recommended for the 6" recommendation of the stove manufacturer?

You need 1" of space between the brick and any combustible materials. Trim can be touching the corners of the chimney but nothing else.

Yes removing the clay would work. But it would also make it hard and expensive to go back to an open fireplace if anyone wanted to. If your clay liners were already shot i would recomend it but otherwise no.

That is why i recomend an oval liner

 

[Serdroid12]

In that case, for the regular 6" round liner with area of ~28 sq in, do you believe fitting a 4.5" x 8.4" oval liner equal to 25.95 sq in be ok? I really want to put the wrap insulation on the liner but will that difference of 3 sq in affect it much?

Also we just got the house last year - looking to stay for at least 18 more years and would heat with nothing but wood during that time.

 

[bholler]

View attachment 233331

In that case, for the regular 6" round liner with area of ~28 sq in, do you believe fitting a 4.5" x 8.4" oval liner equal to 25.95 sq in be ok? I really want to put the wrap insulation on the liner but will that difference of 3 sq in affect it much?

Also we just got the house last year - looking to stay for at least 18 more years and would heat with nothing but wood during that time.

You need to ask the stove manufacturer that question they know what their stove needs to run correctly.