Thimble height

[Eric barber]

hello all. I posted this in a different forum but it really just pertains to the chimney not not the stove type. I am installing a SS liner and noticed my thimble height is about 4" lower then the outlet on my new stove I am going to be cutting a new hole in my chimney. My question is since I am installing a SS liner do I need to install a new thimble, or can I just use run the liner tee through the hole I cut and then put a thimble cover around the section of the tee that protrudes through the side of the chimney to block of the air gap?
Thank you
Eric barber

 

[Jo191145]

Good question. I don't know the legalities of SS inserts.

Legal or not your always better off reinstalling a thimble. At the very least there should be no air gap as you described.
The thimble hopefully is installed without any voids. There's no reason to beleive a SS liner would be any different as it is not a chimney in and of itself, just a liner.

If it's straight into a chimney I doubt the thimble is required. If that thimble passes through a wooden wall structure on its way to the chimney then the thimble should be required. Along with making sure there's still enough solid masonry surrounding it.

 

[Eric barber]

This does not pass through any walls it's a solid block chimney in my basement. If a thimble is required can I use a steel one or does it have to be clay?

 

[Wisneaky]

This does not pass through any walls it's a solid block chimney in my basement. If a thimble is required can I use a steel one or does it have to be clay?

I'd use a steel thimble. That is what I did when I did my install.

 

[bholler]

if it is just going through masonry then no you realy dont have to use a crock at all. Actually many times we remove the old crock to give us room to work anyway. Just seal it all back up well

 

[Jo191145]

What he said ^^^^^^^

 

[Eric barber]

if it is just going through masonry then no you realy dont have to use a crock at all. Actually many times we remove the old crock to give us room to work anyway. Just seal it all back up well

So just use the part that clamps to the tee as the "thimble"

 

[bholler]

So just use the part that clamps to the tee as the "thimble"

Yes i guess just make your hole in the wall then seal off the cores in the blocks with insulation and then mortar. Then run your tee snout out through that wall then pack around it with insulation and mortar over that. You don't need a traditional thimble at all. For the insulation make sure you use a non combustible material like roxul of ceramic wool. If you have insulation left over from wrapping the liner that works well.