Will a 6" round SS liner fit in a 6-9/16" x 10-1/2" clay liner?

I'm installing a Lopi Answer into an existing masonry fireplace and I intend to line the flue. The clay flue is 6-9/16" x 10-1/2" recangle. The flue is 20' tall, and takes a 9" jog to one side, so it does not quite go straigt up. The HomeSaver UltrPro liner is 6-3/8" O.D., leaving a gap of 3/16". I could easily see where the clay liner segments might not align perfectly, or a bit of mortar might protrude, meaning the liner would not fit. The installation guide suggests running a 2-foot scrap down the chimney to test the fit - great idea, but I'm a DIY'er and have no scrap. Hartshearth suggested running a paint can down, but they are bigger than the liner, about 6-1/2 to 6-9/16".

Should I just assume it will not fit and have the liner ovalized? If so, by how much? Can the top be left round to accept the standard collar plate? How do I attach it at the bottom (stove) if it is oval?

I'm sure a full reline is the best way to go, but since the clay liner is relatively small, 68 square inches vs 28 for the 6" round, might it draft well enough if I run 6 or 8' of stove pipe up the chimney?

This is pretty darn close to the topic covered in "Forcing a 6 inch SS liner into a clay lined chimney or reducing to a 5”", so if the slightly larger clay liner changes anything, then I'd like to hear about it, otherwise I think I will try to make my life easier by having the liner ovalized. I still need to know how the oval liner would hook up to the round connectors. Thick leather gloves and force?

Thanks,

Woodpile

I had a local hearth shop try to put a 6" liner down my 6 1/2 x 10 1/2 flue and they couldn't do it because of an offset in the chimney. They never suggested ovalizing, so I told them to forget the lining. Then I found out they make 5 1/2", bought 20' and it slid right down. I did it myself and it took about 1 hr. I have it connected directly to my 6" stove pipe with a small double male section. Then I used furnace cement and screws.

Go with the full reline. My stove drafts much better than before.

Thanks for the reply. How did you adapt the 5.5" liner to the 6" outlet of your stove? The area difference seems reasonable - 23.75 square inches for the 5.5" vs 28.3 for the 6" liner - 15% less area: (28.3 - 23.8) / 28.3 = .15

I think the 5.5" might be the way to go since ovalizing would make the 6" liner stiffer, probably more for bends in the plane of the long dimension, which is the direction I need it to bend to follow the offset in the flue. Ovalizing also means higher shipping costs. Is shipping higher because they cannot coil it as tightly?

I slid in a 6" double male pipe off the end of my stove pipe, then the liner was inserted into that.

That double male section has a little less area than the 6" stove pipe. The OD IS 5.75. And I believe the 5.5" liners OD is a little more than 5.5". I'd measure it but I have a fire going. It turned out to be a pretty good fit, and I also put a little stove cement between and attached screws.

Check out Hart's Hearth, they may have somekind of adapter for this?

Todd, if you used a double-male adapter, that means the top joint fits inside the liner? This is supposed to be a no-no, because liquid creosote can flow out of the joint. But you've been using it this way--any problems? Did you use some of the furnace cement here?

Is your chimney on an outside wall or inside?


Thanks,

Annette

Its not a NO NO, Due to the smaller diameter of the liner, it fits inside the double male pipe. And yes I used furnace cement and screws to attach the liner to the pipe.

I never had a problem with creosote, since I burn dry wood.

Oh, that makes sense. I should've pictured it that way the first time. Thanks!

I should probably say it is a No No, because code states you should use the same size stove pipe/ liner as per stove exhaust. But I have a 7x3" oval stove exhaust, so what size is code for me?