Insulation Question

[CT-Mike]

So I have a 12x12 tile lined brick fireplace with a 6" uninsulated SS liner exiting from my Lopi Freedom insert. I have burned the stove the past two seasons, and I am now looking at adding some insulation and a block off plate to improve efficiency. The question is, if I use vermiculite do I have to go all the way to the top of the flue?

Thanks,

Mike

 

[branchburner]

I can't see why you would have to go to the top, but why wouldn't you? I think you will have less chance of much creosote condensing if you go to the top.

 

[laynes69]

I couldn't fit a blanket around ours, So I poured vermiculite down around the liner. I used 24 cu. ft. to fill ours. When I first started pouring, some of the dust was going into the flue and down into the basement. When I hit halfway or a little more I watched the draft reverse and the dust came up and out the flue. No matter the weather, I haven't had a downdraft since I lined and insulated. I would fill it to the top, thats what I did to reduce the chance of buildup.

 

[fishingpol]

Mike,
Why not an insulation wrap blanket made for liners? Seems like you have enough room in a 12" x 12"? Was liner install difficult?

Jon

 

[CT-Mike]

I only have about 8" between the bottom of the lintel and the top of the stove, so installing the liner was a major PITA. I am not willing to pull it just to wrap it, so I am looking at vermiculite.

 

[oldspark]

To the top is the only way to go.

 

[branchburner]

Perlite may be better than vermiculite. Be aware of how easily it can sift down through the smallest crack.

I don't have a blockoff; instead, I stuffed a foot or so of rock wool around the liner above the smoke shelf, then poured in a small amount of perlite/cement slurry from above to make a good seal (but still allow the liner to be removed). I then filled the space to the top with loose perlite. (This hybrid application is obviously not an approved insulation method that is in accordance with any UL liner specifications, if that matters to you.)