Normal chimney heat retention?

[Phoenix Hatchling]

Never took note of this before and maybe it just wasn't quite as obvious. The snow on the roof surrounding the chimney was/is melting away. Is this normal for the chimney to retain that much heat? There is a 6 inch single wall Forever Flex liner going up from the stove in the basement. I went up in the attic and the infrared thermo read 60 degrees on the outside surface of the chimney running through the attic. The surrounding temps in the attic ranged from 17 to 32 degrees.

 

[HotCoals]

Uninsulated liner through clay tile?
I'm just curious. Looks fairly normal though.
The brick is going to adsorb some heat no doubt then release it through temp differential.
Block off plate?

 

[begreen]

Is the liner insulated? Is there a damper sealing block-off plate in place?

 

[Phoenix Hatchling]

The liner is uninsulated and there is a damper sealing plate.

 

[begreen]

A 4-500F flue liner radiates a lot of heat that gets trapped in the chimney cavity.

 

[EatenByLimestone]

Around your chimney you have an air gap. That gap lets air rise along the outside of your chimney. The air hits the chimney flashing and is pushed out to your roof deck where it flows upwards between your rafters.

 

[HotCoals]

Around your chimney you have an air gap. That gap lets air rise along the outside of your chimney. The air hits the chimney flashing and is pushed out to your roof deck where it flows upwards between your rafters.

Then what keeps the rain out..just askin'.
I'm sure there is a insulation gap where the chimney goes through the attic though and that alone could melt some snow.

 

[EatenByLimestone]

Flashing keeps the rain out.

You're right, the insulation gap is enough to melt snow. You'll find the outside of the chimney has quite a draft going up around it.

 

[Phoenix Hatchling]

So from what I gather, this is normal occurrence and I should not be running for cover. I suppose that the longer the stove is left to burn as I have done, the more thermal retention takes place in that mass, just as any other material. Didn't realize that it threw off that much heat though.

 

[pgmr]

I had the same issue a couple years ago and wrote about it in this post: https://www.hearth.com/talk/threads/insulating-exterior-of-masonry-chimney-in-attic-update.60625/

 

[EatenByLimestone]

Is it normal, probably. Is it acceptable? That's up to you. I didn't think it was so I stuffed kaowool and roxul into the air space and then covered it with firestop caulk so I could stop the air from flowing up the outside of the chimney. There is still a little bit of heat transfer, I'll never stop it, but the air doesn't have the ability to run completely up the outside of the chimney anymore.