Chimney relining options for an earth sheltered home

[kevin588127]

Sounds like a lot of heat getting away up the chimney. Have you plugged off the OAK until you get a replacement stove? Might be interesting to see if you lose/reduce your updraft.

Will do that tomorrow. The fresh air pipe is still hooked to the old stove. You can feel a very slight bit of cold coming out of the stove pipe.

 

[kevin588127]

So the duraliner isn't going to fit without removing the clay liner. I dropped a piece of 6" PVC down and it hits the joint of the first clay liner. Seems they didn't get them lined up perfectly. The pipe measures 6 and 5/8 inches just like the duraliner is supposed to be. Bummer.

I believe I'm going to try a partially insulated liner. I think I can insulate 4' of the liner where it passes through the 8" stainless. That would leave the top 6' and the coldest part of the chimney uninsulated. I would also stuff the remainder of the lower cavity with as much insulation as I could get in there to mitigate the drafting issue. Rockford sells their premium kit for right around $1000.

I don't believe I'd be breaking code or creating any potential dangers doing it this way. The only concern is if I end up having moisture problems in the old flue or drafting issues with the liner itself.

Any holes in my plan? Any recommendations on other quality liners that may be cheaper or better? Any issues with the slight amount of creosote left in the old clay liner?

 

[kevin588127]

So I finally got this project done. We had to extend the hearth so that took some time. And the chimney guy was backed up a few weeks.

His original plan was to demo the chimney down to it's last course, one course above the concrete. This would have left one course of clay liner to remove and maybe that internal stainless piece. He was going to run single wall up to the ceiling and then transition to class A double wall. Approx 6' of double wall would have been exposed above grade. I liked this idea though it was a bit more expensive.

I say original idea because as they set to work, he came down and said that he thought an uninsulated liner may be a better option. I was hesitant but the original plan was contingent on what he found when he knocked the old one down. I agreed to it for a few reasons. It was cheaper and faster. He guarantees no issues with water or drafting. If this doesn't work, the other option is still on the table.

They ran after supplies and were done in a few hours. The inside cavity was stuffed with insulation and the top was capped and sealed around the liner. The liner they used was fairly stout but the single wall they used is the kind where you have to pop the seams together. Not a great finished look IMHO.

I fired it up for the first time this evening. So far I'm very happy. It started easy, way easier than our old stove. It has been very easy to maintain a nice fire all evening. This stove seems to like to run with the air inlet at 25-50 percent so maybe my undersized 3" OAT will be ok.