Insulation question

[tkuhe]

Sorry to repeat topics but I have used the search and couldn't find the answer.

I am planning on installing a wood insert and it doesn't look like I will have enough room to add insulation to the 6" flex liner. Am I just SOL or are there other options? From what I have read it sounds like the insulation will turn a 6" pipe into an 8" pipe and looking up my chimney I don't think I will be able to pass that down. Liner will be ~25'. Masonry chimney is exposed so it will be cold in the winter. I live in Massachusetts.

Is it rec'd/ok to use a 5" pipe with insulation more than a 6" w/out? Or should I just focus on making a good block off plate and deal with the extra creosote build up that an uninsulated pipe will yield?

Thanks for any help.
-Tucker

 

[zzr7ky]

Hi - I would try passing 6" rigid. It is strong and smooth (no worries cleaning). A good block off and call it good. Modern stoves opperated decently really do not creosote much in my experience. Check often the first year, or with new operators.

 

[Jags]

Tucker - you can only do what you can do. I second the rigid 6". There are some pour in place insulation options but I don't know squat about them. Get a good top and bottom block off plate and run good stack temps and you should be fine.

Tons of installs don't have insulation and they work fine. Is insulation better...in my opinion..yes. Required....no (this is assuming that your chimney is code for a liner)

 

[tkuhe]

Thanks for the replies.
Why rigid over flex?
I thought flex was easier to install and less expensive but I assume there is a cost for the convenience.
Is it because the smooth interior of the rigid is that much better that the flex?
How much harder is it to install rigid?
Thanks again.

 

[Jags]

If the rigid does not cause an installation issue, I suggest rigid because of the ease of cleaning. If the installation is a little ugly and the flex will make it easier, then use flex.

 

[tkuhe]

So am I right in saying that the main benefit of rigid is ease of cleaning?

 

[theheatelement]

if it's straight down, use rigid... if you have any turns use Flex...simple... for a DIY... it's just easier this way..

 

[branchburner]

Rigid is also thicker (= heavier) and will also potentially draft better because of its smooth interior surface.

 

[bren582]

I went wioth FlexKing Pro liner as a compramise between flex and rigid.

Features:
--> Double Wall. Made from a single strip of .006 316Ti Stainless Steel
--> Total overall thickness .012 plus air space between layers.
--> Smooth wall on the inside increases draft by 20% and reduces creosote build-up

I can't be sure on the 20% increase claim but it is a great deal smother on the inside versus single wall flex liner..

 

[tkuhe]

Well I got up on the roof and measured this morning. The internal looks pretty clean, I was surprised how much warm air was blowing up in my face with the damper open, I don't think draft will be much of an issue.
Internal clay dimensions are roughly 7" X 11.5" so I think it will be pretty tight to try and squeeze insulation around a 6" liner as it is my understanding that w/insulation you get roughly an 8" diameter pipe when all is said and done.
Top of the chimney to the floor of the hearth is 24.5' so I think I should be ok w/25' of pipe but that doesn't give me much wiggle room, I get 20" back when you consider the height of the insert.

Is it worth looking into oval pipe and insulating that? Or should I just

I'll look at Flex King Pro, thanks.

Anything I am missing?

 

[tkuhe]

OK.. Just bough the PE D1 insert and now I need to pull the trigger on the liner.
The dealer put up a good argument for Ventinox but quotes somewhere close to $700 for the 6" x 25' kit.
Is Ventinox that much better than say Flex King or Flex King Pro?
Flex King kit $427 shipped
Flex King Pro $595 shipped

Please help me decide.