repair clay before liner install?

[fulksb]

I am getting ready to install new insulated ss liner in a masonry chimney with 8.5 by 13 clay liner. The clay liner is in good shape except for at the very top where it has been exposed to more weather. The top few inches where it meets the crown is cracked and one small chunk of clay is missing. Do I need to break out and replace this clay liner with a brand new one before installing new ss liner? I already need to break off the crown and replace because it is also cracked, so I think I could simply rebuild the crown such as to accept the new stainless steel crown and not need a new clay liner piece. What is your advice?

 

[fulksb]

I do not currently have a picture that I can upload, if you all need one I could get up on the ladder again and take a few photos this weekend. However, I did a quick Google search and found a picture of another chimney that shows similar damage so you know what kind of problem I am looking at. So, like a said above, most of my liner is in good shape, it is just the top few inches that has cracks and a missing chunk and looks similar to the one in this photo. I am already relining with a new insulated ss liner, how do i deal with this cracked clay?

 

[btuser]

Not an expert but I know a lot of installs require the removal of the clay liner to fit the required size ss liner. That's a job I never want.

 

[Rickb]

I would think you could chip the clay liner even with the top of the stack then cover the whole thing with a metal cap. Then you just cut a hole in the cap the size of your pipe.

 

[BrotherBart]

Heat differential causes it. If you are sure the rest of the tiles are not cracked cut it off at the top of the new crown and install the liner. Mine has had two cracks in it because it sticks up 12 inches into the cold air for 25 years and hasn't fallen apart. Sweep told me a long time ago that he sees it all the time in top tiles.

But when you are removing a crown it is really a lot easier than you would think to replace that top tile section at the same time. I am going to replace the one in mine next year when I replace the crown.

 

[Dave A.]

Are you sure you're going to fit an insulated liner in that flue? 8.5x13 ends up at 6.5x11 inside. 6" liner uninsulated is about 6.25" od. As far as the clay, agree with the others, not to leave it that way. Not sure chipping is the way to go. If you cut it off, with the right blade in a motorized tool, you'd get a cleaner cut.

 

[fulksb]

Where can I find the clay liner, no one around here seems to have them?

 

[Beer Belly]

Where can I find the clay liner, no one around here seems to have them?

(broken link removed to http://nwct.craigslist.org/mat/4127964833.html)

 

[BrotherBart]

Home Depot should be able to get the flue tile for ya. Or tell you a local building supply place that can get them.