This is why I am told I do not need an insulated liner. Is this correct?

[clydesdale]

For starters, my chimney liner will be a 35 foot kit and the liner will be in a mason chimney that is on an outside wall that faces south-east. I have been told by a few installers that they will insulate the top and bottom of the chimney and that will be all I need. They claim that it is not necessary to buy the insulated liner if I am going to insulate the top and bottom of chimney. Thoughts?
Also, is it ok to ovalize the liner as it passes through the old damper door?

 

[branchburner]

Given that it is an exterior chimney (=cold), I would insulate the entire liner. At least one other forum member would suggest you also do it for safety and code reasons, since you and your installers probably cannot be sure of clearance to combustibles for the entire length of the chimney. I believe it is okay to slightly ovalize the liner, but what does the damper opening measure?

 

[EatenByLimestone]

I would insulate it. It's a tall chimney and that gives the gasses a chance to cool off enough to condense.

 

[begreen]

The insulation on the liner is primarily for safety and second to reduce cooling of the flue gases as they travel up the flue. The safety is because most chimneys don't have the required clearance to combustibles. 1" is required for exterior chimneys. Warmer flue gases mean stronger draft and less creosote buildup.

 

[Smoked]

Yes insulate and I hacked my damper frames out to fix the clearance issues. When I moved from my previous house and took my stove, I just added a top seal damper because they are better anyway. Use an angle grinder to cut out as much of a section as you need.