n00b needs help please

[tkuhe]

sorry to bring this up again but I am trying to buy a liner for my new pacific insert and I am confused by the install manual and I feel I am suffering from information overload.

What exactly does this mean?

“In a case where a masonry chimney is found to have at least 1” clearance
to combustibles”
“First determine if the chimney you are relining has at least 1” of clearance between its exterior masonry surfaces and combustibles.”

So I have an exterior chimney, clay lined with 8"x12" and I am trying to buy a liner. I found some Homesaver OvalFlex at a decent price but reading the manual seems to imply that I will need to add insulation unless I am reading the above wrong?
How would a chimney have a 1" clearance?

My fall back would be to either buy a magnaflex kit or a flex king kit online.

 

[Todd]

As far as I know insulation is only required if you have no clay tile or the tile is in poor shape. You will have a hard time getting a 6" liner with insulation wrap down a 8x12 chimney anyways.

 

[ansehnlich1]

The 1 inch airspace is referring to a 1 inch space between the exterior masonry chimney and the exterior wall of the house. Many, if not most, exterior brick or block chimneys are built right up against the house. We built a home about 2 years ago, code was 2 inches of airspace between our exterior brick chimney and the exterior wall of the house.

 

[tkuhe]

The 1 inch airspace is referring to a 1 inch space between the exterior masonry chimney and the exterior wall of the house. Many, if not most, exterior brick or block chimneys are built right up against the house. We built a home about 2 years ago, code was 2 inches of airspace between our exterior brick chimney and the exterior wall of the house.

So then since my chimney is built right against my exterior wall, if I want to use the OvalFlex I would have to get insulation.
Do you know off hand if there are flex liners that do not require this? I will check on the magnaflex and the flex king as those were the others I was looking at. I just figured the ovalflex would be much easier to install than the 6" round given my 8"x12" clay.

 

[tkuhe]

I still don't really understand why I would have to add insulation? I currently use the firse place as is and would think that adding the flex liner and an insert would only make it safer as a whole. What difference does adding the insulation make?
I also noted this from Toms site;

To maintain its listing to the UL 1777 Standard, additional insulation must be added to your Forever Flex Liner installation if both these two things are true:
Your existing chimney is unlined, partially lined, or has a liner with open cracks in it
AND
There are combustibles physically touching the chimney at any point.

Does that mean if my chimney doesn't have cracks I wouldn't need the insulation, and if that is true how would anyone figure out if there are cracks without dropping a camera down my chimney?

My brain hurts trying to get this all sorted out!

 

[ansehnlich1]

I still don't really understand why I would have to add insulation? I currently use the firse place as is and would think that adding the flex liner and an insert would only make it safer as a whole. What difference does adding the insulation make?
I also noted this from Toms site;

To maintain its listing to the UL 1777 Standard, additional insulation must be added to your Forever Flex Liner installation if both these two things are true:
Your existing chimney is unlined, partially lined, or has a liner with open cracks in it
AND
There are combustibles physically touching the chimney at any point.

Does that mean if my chimney doesn't have cracks I wouldn't need the insulation, and if that is true how would anyone figure out if there are cracks without dropping a camera down my chimney?

My brain hurts trying to get this all sorted out!

Well, there are woodburners on this site that are much more knowledgeable than I when it comes to liners. Reading this latest quote, it appears that if your current liner is deemed to be in good shape you don't need to insulate. However, only way I know to determine that is to get a sweep to inspect it, sometimes that includes running a camera down through.

 

[begreen]

A level 2 inspection is recommended when changing the use of the chimney. A thorough chimney examiner often does drop a video camera down the flue. If this is an exterior chimney go for the insulation. You will get much better draft, faster starts and less creosote build up.

 

[tkuhe]

8"x12" clay liner.
Pacific Insert 6" opening.

How can I insulate? Or do I get the OvalFlex and insulate that?

 

[tkuhe]

So is it safe to say that most people who install a 6" flex iner in a chimney with 8"x12" clay do not use insulation and therefore do not meet UL 1777?