Liner & Insulation Recommendation for New Stove - Osburn Inspire

[Heatman]

Hey all - I've posted a couple of times over the last 2 years about a stove recommendation for my funky 4 sided fireplace that was already retrofit by a previous owner for a wood stove. They cut through the damper and installed a stainless steel liner plus insulation in the chimney.

The contractor I hired to repair some cracks in the external chimney and install the new Osburn Inspire stove thought that the existing liner was in decent enough condition to reuse, but when they tried to connect the liner to the stove pipe, it cracked and needs to be removed.

So I now have 3 options that I'm hoping to get some help and feedback on. The contractor is going to remove the existing liner, as well as the existing insulation, and will install either 1) a new liner (no insulation), 2) an insulated liner, or 3) a new liner + wrap around insulation. The costs are 1K, 1.7K and 1.5K respectively.

The installers opinion is that b/c I have a long chimney (~20 ft), the ROI of an insulated liner or liner + insulation is going to be relatively small.

As much as I'd like to minimize extra cost due to this unforeseen circumstance, I'd like to take the opportunity to do this right the first time. For the experts out there, could you let me know what option you would go with and why? Will the insulation only help with drafting and the initial starting of the fire?

I'm including pics of the fireplace and the chimney in the attic. The chimney flue is quite large so I don't think insulation is going to play a huge part from a safety perspective (but please correct me if I'm wrong).

Thanks in advance for your help!

 

[Ctwoodtick]

I’m not a professional but you should definitely do insulation- whether a preinsulated liner or wrapped on-site. The purpose of the insulation is for protection from radiant heat from liner. The slight increase in draft is nice but not the purpose of the insulation. The installer really should know that. I understand that the chimney is large but still…. When I see your picture of the chimney in the attic, it’s not all that big. Regardless, you won’t regret the insulation.

 

[EbS-P]

Code says unless you have 2” clearance to all/any combustibles round the entire chimney structure you are required to insulate. I can’t tell from the picture in the attic but guessing you don’t have 2” gap around the block chimney.

So two or three. Plan on wrapping a piece of split 8” stove pipe around the liner where it comes off the stove. It looks better

 

[kborndale]

Did your contractor say if the 2" to combustibles was met? That is code and if it isn't met than it must be insulated. We are talking about $500. That isn't worth it for peace of mind?

 

[Heatman]

Thanks for the feedback all.

Totally agree that insulation is the way to go.

Next question is, would it be beneficial to add additional insulation within the chimney flue? I believe the flue is quite large and more insulation could be added (outside of the insulated liner), but not sure if that provides a benefit or not.

 

[EbS-P]

Thanks for the feedback all.

Totally agree that insulation is the way to go.

Next question is, would it be beneficial to add additional insulation within the chimney flue? I believe the flue is quite large and more insulation could be added (outside of the insulated liner), but not sure if that provides a benefit or not.

You will want to seal the are between the liner the the old flue to stop cold air from falling down. We call it a blockoff plate. I see no reason to add insulation around an insulated liner if you have a block off plate.

 

[Heatman]

@EbS-P - the damper is still present in the chimney... previous owners cut through the damper to install the liner, so I'm assuming that the damper is the block off plate in this case?

 

[EbS-P]

@EbS-P - the damper is still present in the chimney... previous owners cut through the damper to install the liner, so I'm assuming that the damper is the block off plate in this case?

If you can air seal around it well enough It could work.