So already have a super tall stack, 28 feet if I remember right. Center brick, lined and insulated with 6" SS. I have a steep pitched roof and went outside the other day and noticed eddy currents out the top of the cap, so I got to thinking I have some disturbances that need to be corrected. I will occasionally get some backpuffs on the right day when the air is shut down. On the right day I can watch the smoke and steam blow down the roof line. The supervent deluxe rain cap has helped a ton in windy situations. So I did some calling and checking here is what I came up with and ordered. http://www.woodstovepro.com/store/Selkirk-6-SuperPro-Adapter-Plate-JSC6AP-p20004.html Connect this to my top plate and liner, and then be able to twist lock on a 36" piece of supervent class A to give me 7 feet above the peak of the roof. When I want to clean it I will just take the one section down. I already have great draft but I think with the spring and fall it will only help coupled with getting into some cleaner air.
That's a fairly inexpensive fix....if it works. I hope it does. I see startup smoke coming down off the roof opposite wind direction sometimes. I'm waiting for warmer weather to see how much rollout I have this spring.
I have a very steep roof pitch and when the right conditions exist smoke can roll down the roof. I hope it works too. One benefit will be having the class A rain cap properly attached. The other thing is with the twist lock connector at the top, I can easily bring the height back to where it was before or add height.
4 feet above the peak is a brick chimney with a 1/8" thick galvanized plate that I fabricated and anchored in and the liner is band clamped into. The S.S. adapter plate I bought will be bolted to the old 1/8" top plate, banded to the ss liner and only one section of Class a will be attached to it. According to the manufacture, you do not need to brace 3 feet of class A.
Thought I would do an update on this project.: I pulled the liner top plate off and swapped it with the class A adapter plate and bolted it down, added a 3 foot section of suipervent with the cap on top. Really quite slick if anyone is looking to add height to a liner. Fifty degrees tonight and lit the stove off, went out with the spot light and the smoke is traveling straight off in the sky now. I should be able to close the air nearly shut without issue hopefully now. I am not sure what will happen next winter when the draft really gets cranking but thankfully I have a turn key damper in the single wall.
Is the Fireview on this chimney? If so, I don't remember reading of a Fireview or Keystone ever back puffing, even on a 13' (I think) chimney like Backwoods Savage used. Like we always say, every install is different. Hopefully the extension fixes you up. Slick way to extend a liner.
Yes, a fireview is installed on this chimney. If you do some reading and asking around you can make the stove backpuff on certain situations. The right air deprived stove, draft and fuel load can make any stove backpuff. My main goal was to get the stack higher, I have a steep pitched roof and certain wind directions can make the smoke slide down the other side of the roof on reloads.
We have had a couple very minor back puffs. It's been a long time ago so I can't say much about them except that if we had not been in the room at the times we'd never have known it happened. It was never like the big PUfF one usually gets, just sort of a phft and it was done. Fire really took off for a time too but no harm done. Just a very slight hint of smoke smell is all we had.
I have a short chimney (13') and most of the time draft is good but I think it could be better in shoulder season temps. I may have to try this next year thanks for posting this Jdonna.
I hope the beauty of changing to the class A adapter, you can add or take away sections depending on the season. We are having fun now with this spring shoulder season!
So that would make it a 31' chimney, right? Do you have too much draft when it's really cold out with the 28' now? That's a bigun!
I do have plenty of draft when it's cold, you have to stay on top of making sure the stove is air tight and we also have a turn key damper as a backup plan.
