Exterior Chimneys & Block Off Plates

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BuckStove91

New Member
Oct 11, 2014
5
KY
Hi everyone. I purchased a home that is built with one exterior chimney that measures about 18 ft. I have a Buckstove 91 insert.

The owner before me had only set the insert into the opening of the fireplaces and installed the metal surround. I take it he only used it for the occasional fire maybe during the holidays or something. It was venting directly into the fireplace with no liner! In any case it was not installed correctly OR to be used as a primary heat source.

I, on the other hand took it a step further since I grew up with wood heat. I took to these forums, learned as much as I could then, with help of a friend, removed the insert (heavy!), cleaned the chimney, done some demolition and cutting of the damper etc etc. and installed a new 8 inch insulated liner with a top plate and chimney cap.

I think it was easier doing all the other work than trying to get a decent fit of the liner to the insert. Hindsight tells me I should have ordered a fitting that would have angled the appliance connector about 20 degrees. I had cut the damper and chipped several brick away, but, in the end we got it to work and I now have a very well burning stove that's putting out a lot of heat.

Due to the above mentioned difficulty on the fitting, I did not install a block off plate above the insert. As much as I was having to move and try to flex the liner to get it to attach to the insert - I couldn't see trying to make a block off plate and get it to work.

My question is this: I've researched block off plates on the forum and it seems they are beneficial. Can I really expect a great increase in heat, if later on I decide to pull the insert out and install one? I had considered perhaps next year during the warm season to pull it and install a block off plate and also insulate with Roxull around the sides and back of the insert opening. Has anyone ever installed a block off plate after they installed their liner? If so, what's your thoughts on the results? Thanks for the input!
 
Insulate that fireplace and install a block off and you will see a huge difference. Installing a block off place with the liner already in place makes it easy to figure out where your hole needs to be, plenty of DIY's on here for the block off plate that show how to do it with liner installed.

At a minimum go buy some Roxul at Lowes and stuff the damper area with that.
 
https://www.hearth.com/talk/wiki/make-a-damper-sealing-block-off-plate/

If need be, it can be made or cut into two sections for easier install.


Thanks to all for the replies! I may wait till the cold season is over and do it. I need to completely remove the insert to cut a couple pieces of sheet metal for the block off plate. I noticed at Lowes, they have the Roxull. I'm not sure what type of barrier it has on it though. Anyone have ideas on installing it inside the opening for the insert? Should I make baking pieces from sheet metal for the opening also? Again, thanks!
 
I don't have a block-off plate as such, but I cut a batt of Roxul slightly bigger than the dimensions just above the lintel so I could get a tight fit to hold itself in place. Then I cut the hole for the pipe and made a slit at the edge so I could get it around the pipe. It's an interior chimney so I don't know if it's as big a benefit as you would get with an exterior. I don't have the surround installed, to get more heat into the room.
As far as the glass, it will stay pretty clean with dry wood in the 91. I just replaced all the gaskets in the stove including the door glass and bay windows, and I can tell already that the door glass will stay cleaner. I'll see how much cleaner as the season progresses.
 
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