Pourable insulation in a TIGHT liner install

[ikessky]

I'm getting ready to order some perlite to dump into my chimney and then I got thinking, how is this really going to affect my setup? Right now, I have a 6" liner in a 7"x7" ID clay lined chimney. I know the liner is touching the clay in numerous spots. I'm not sure I will be insulating much more than just the four corners (round liner in a square hole), but I've been thinking that whatever insulation I can get in there should help to keep the heat in the liner rather than soaking into the surrounding tile and masonary. Then I got thinking, will having spots of the liner that are insulated and spots that are not create some kind of negative effect like creating hot spots or something?

 

[theheatelement]

Personally... I wouldn't insulate it... the outside diameter of most liners that size are 6 3/8 so your talking about 5 of an inch on both sides, your clay liner will insulate it enough nevermind the heart ache you will have getting the insulation down there... now if you had a 12x12 chimney I would say otherwise...

I'm getting ready to order some perlite to dump into my chimney and then I got thinking, how is this really going to affect my setup? Right now, I have a 6" liner in a 7"x7" ID clay lined chimney. I know the liner is touching the clay in numerous spots. I'm not sure I will be insulating much more than just the four corners (round liner in a square hole), but I've been thinking that whatever insulation I can get in there should help to keep the heat in the liner rather than soaking into the surrounding tile and masonary. Then I got thinking, will having spots of the liner that are insulated and spots that are not create some kind of negative effect like creating hot spots or something?

 

[CarbonNeutral]

Personally... I wouldn't insulate it... the outside diameter of most liners that size are 6 3/8 so your talking about 5 of an inch on both sides, your clay liner will insulate it enough nevermind the heart ache you will have getting the insulation down there... now if you had a 12x12 chimney I would say otherwise...

I'm getting ready to order some perlite to dump into my chimney and then I got thinking, how is this really going to affect my setup? Right now, I have a 6" liner in a 7"x7" ID clay lined chimney. I know the liner is touching the clay in numerous spots. I'm not sure I will be insulating much more than just the four corners (round liner in a square hole), but I've been thinking that whatever insulation I can get in there should help to keep the heat in the liner rather than soaking into the surrounding tile and masonary. Then I got thinking, will having spots of the liner that are insulated and spots that are not create some kind of negative effect like creating hot spots or something?

I wouldn't agree that the clay liner will insulate it - the clay is a very poor insulator, and the point of the perlite/whatever is to stop heat transfer during a chimney fire through the clay to wood structure. That said, I do agree that your chances of actually achieving any significant coverage is slim. I would suck up the no insulation, add a block off plate, and make sure you inspect and sweep often during the heating season.

 

[theheatelement]

I meant the air around the liner... The air will insulate the liner in that tight of gap...

 

[ansehnlich1]

We have an 8 inch clay liner, I'm guessin' it's 7 inches inside diameter, more or less.

We ran a 6 inch flex king pro liner down it.

Then poured vermiculite around it, indeed, a whole bunch went down around that liner.

If I recall it was over 2 bags of the stuff.

Wouldn't change a thing if I'd do it over again.

And, I know that flex liner is touching the clay liner here and there and I couldn't care less

 

[ikessky]

Thanks guys. I'm thinking that for the price of the perlite, I'm just going to get some and see how much I can get down there. According to one calculation I found, I'm probably only going to be able to get a little over a bag down there.

 

[Captain Hornet]

If you're tight on the bottom with a good block off plate, you can use children's playground sand. It'll cost you a couple of bucks at Home Depot or Lowe's and that well be for a big sack. It'll pore in and settle in all tight spots around your liner and be a super insulator. The other good thing is that you can get the liner out easy if you ever want. David

 

[CarbonNeutral]

If you're tight on the bottom with a good block off plate, you can use children's playground sand. It'll cost you a couple of bucks at Home Depot or Lowe's and that well be for a big sack. It'll pore in and settle in all tight spots around your liner and be a super insulator. The other good thing is that you can get the liner out easy if you ever want. David

Sand is five to eight times less insulating than perlite. It would not be a suitable barrier to prevent the spread of heat during a chimney fire, especially in tight situations as per the OP. Also, combine that with the smallest leak in your block-off plate, and within a few weeks you won't have any sand up there anyway.


http://www.engineeringtoolbox.com/thermal-conductivity-d_429.html

 

[ikessky]

The liner is installed in a chimney that runs from my basement, through the living area, and out the roof. The only place for the perlite to go is down to the basement where the clean out is. I have already stuffed a bunch of fiberglass insulation in there and will also be siliconing the clean out door shut. So, I'm not really worried about losing any material. I think the perlite will also follow the spiral and contour of the liner, so I shouldn't have to work too hard to get it down the open areas.

 

[CarbonNeutral]

I wouldn't have worried about the perlite seeping out - but the sand, that would be a different matter

 

[Todd]

Have you thought about just stuffing rock wool insulation around the top couple feet so the warmer air below would insulate the liner?

 

[ikessky]

I have a bunch of extra stove door gasket that I wrapped around the liner and stuffed around the top portion. I'll take a picture when I redo the chimney crown and you will see just how tight it really is.

 

[BrotherBart]

Can't tell ya anything other than don't even think about pouring sand down your chimney and that I stuffed the top three feet or so with Rockwool and creosote or bad draft became a distant memory.

If the wood ain't dry, you can insulate till the cows come home and you will still crap up a chimney.

 

[ikessky]

Wood was cut and split last spring/summer. That won't be an issue now that I'm at least a year ahead. I just figured any little bit will help with an older smoke dragon.