Insulation in Ceiling Support Box?

[fakie99]

Hi - I just installed a chimney system for my freestanding woodstove. Used double wall from the stove to an adapter, then triple wall out of the roof. To support the triple wall chimney, I used a kit (forgot manufacturer) that used a sheet metal box (16"x16") to be fastened to the rafters, then the chimney sits in it. My question is - should I have put insulation in the chimney support box? Seems like a good place for heat to escape....

Diagram is attached - any thoughts are certainly appreciated.

Jim

 

[begreen]

No insulation goes in the support box.

 

[Highbeam]

That support box is also the insulation keep away box. You'll notice it is wider than the chimney by about the same distance (2"+)as the required clearance to combustibles. You are not supposed to get anything between the box and the chimney and if something falls in there then you'll want to vacuum it out pronto. You can airseal this box to the ceiling/rafters. I did this just two days ago while air sealing my attic.

 

[G-rott]

Anyone know about using rockwool or any other non combustable insulation in that space?

Garett

 

[DiscoInferno]

I have a 2-story chimney kit; the ceiling support is uninsulated and sits between the first and second floors. The attic insulation shield sits above the second floor to keep insulation from the pipe. However, part of the kit was $20 for insulation to wrap around the chimney inside the insulation shield. I was expecting it to be some special high-temp insulation - nope. Looks like regular unfaced fiberglass batt insulation. But since it's listed and the manual shows where to put it it I assume it's OK.