Adding insulated chimney to top of 5"SS Rigid Liner?

[Sir_Lancelot]

In order to (hopefully) improve the draft of my short chimney (12' high from thimble) I'm thinking of adding 2 to 4 feet of insulated chimney to the top of my 5" SS Rigid Liner. What is the best way to do this? Is there an adaptor that can be used to connect the liner to the Class A pipe and what would be the best way to insulate the short section of liner that extends outside the clay tile?

Also, how high can I extend the the chimney with Class A without having to provide support for the Class A section?

I've included a picture of my chimney that was taken before it was lined (I took a more recent pic but left the camera at home!).

The reason I'd like to extend the chimney height is to help improve the draft when it is a little 'warmer' outside. The chimney drafts okay when it's cold out, but is a little sluggish when it's a bit warmer out...more difficult to start and some smoke spillage when opening the door to reload.

Thank you for your help and advice.

 

[snowtime]

First I would get some single wall and experiment to see whats the best length. Its a cheap way to be sure. As to the connection it depends on how much liner is exposed. Possibly pouring to the top edge to get proper support for liner. Either way your going to have to use extra support for a significant addition to chimney.
If just 2' or less will do it then you can probably just put the single wall on and be good. Might be a little extra creosote but thats easy to watch. You can get stainless single wall.

 

[Sir_Lancelot]

Well, I attached a 30" piece of pipe to the top of the liner and the draft has indeed improved quite substantially. As such, I'd love to add a two foot section of class A to the top of the liner. I've attached a pic of the test extension as well as a close up of the existing top of the chimney. The question is, how do I go about attaching the class A to the 5" rigid liner? Would a stove pipe adapter screwed into the top of the liner work? Also, what would be the best way to insulate the small gap that would be between the existing plate and the adapter? I was thinking of shoving a bit of Roxul in that space (it would be protected by the storm/rain collar that I'd add to the bottom of the class A). Or is this small gap really that necessary to insulate? Any help would be much appreciated. Thank you.

 

[DAKSY]

You should be able to get an adapter from a flex to Class A pipe, but it will hafta
be manfacturer specific (the adapter & Class A from the same source...).
The adapter will mount to your flue tile or mudcap & will
probably need an additional brace kit to ensure that it remains in place.
There shouldn't be any exposed liner needing to be insulated if you do it correctly.
You will need to get another chimney cap as well...

 

[Rob From Wisconsin]

That's a pretty tall extention.
Support??

 

[Sir_Lancelot]

Thanks for the help so far...

 

[jbrown56]

Hi,

I have 20' of single wall rigid with about 4' above the chimney cap and it's fine with one cleaning per year.

Jim

 

[Sir_Lancelot]

Hi Jim,
I've read through some of your posts and would be interested in seeing a pic of your chimney top. Any chance that you could post a pic? Thanks.

 

[Fsappo]

You can use a 6" metalbestos or similar anchor plate with a section of class A pipe and a class A cap. Metalbestos does make 5" class A but they dont make the anchor plate in 5". This means you'll need to get yourself a stainless reducer with a 6" female and and a 5" male end. I'd get a 4' length of class A. Retail on those parts may run $400-$450 US.

 

[jrprusak]

In order to (hopefully) improve the draft of my short chimney (12' high from thimble) I'm thinking of adding 2 to 4 feet of insulated chimney to the top of my 5" SS Rigid Liner. What is the best way to do this? Is there an adaptor that can be used to connect the liner to the Class A pipe and what would be the best way to insulate the short section of liner that extends outside the clay tile?

Also, how high can I extend the the chimney with Class A without having to provide support for the Class A section?

I've included a picture of my chimney that was taken before it was lined (I took a more recent pic but left the camera at home!).

The reason I'd like to extend the chimney height is to help improve the draft when it is a little 'warmer' outside. The chimney drafts okay when it's cold out, but is a little sluggish when it's a bit warmer out...more difficult to start and some smoke spillage when opening the door to reload.

Thank you for your help and advice.

Did you check into installing a draft inducer??

 

[Sir_Lancelot]

Yes, but didn't like the power consumption of those devices. Maybe I misread the literature of the one I looked at, but I don't believe that it was temperature actuated. I really thought (mistakenly) that extending my chimney two feet would be easy and not overly expensive.

 

[Sir_Lancelot]

Bump....

Am now thinking of adding 2 feet of liner and slipping a 30" section of class A chimney around the additional 2 feet of liner (including the 6" of flashing) in order to insulate the exposed liner. Any other ideas?

 

[RedGuy]

I simply added an extra flue tile to the top of my chimney to give me an extra 2 feet I needed to properly clear the peak of my house. Cost me $17 for the tile, $10 for some good high temp silicon to seal it together. Though I do plan on adding bricks around it once the weather warms. It's functional even if it does look alittle silly, kinda looks like my chimney is giving the neighbors the finger as it's a 3 flue chimney with the center 2ft taller LOL.