Gap between Flue and Crown Clay Piece

  • Active since 1995, Hearth.com is THE place on the internet for free information and advice about wood stoves, pellet stoves and other energy saving equipment.

    We strive to provide opinions, articles, discussions and history related to Hearth Products and in a more general sense, energy issues.

    We promote the EFFICIENT, RESPONSIBLE, CLEAN and SAFE use of all fuels, whether renewable or fossil.
  • Hope everyone has a wonderful and warm Thanksgiving!
  • Super Cedar firestarters 30% discount Use code Hearth2024 Click here

SiBuddy00

New Member
Mar 28, 2020
3
Normandy Park, WA
Hello,

Was measuring up the chimney for caps and noticed a 3/8" to 1/2" gap in the location circled below. I found a couple threads describing situations I believe were similar, but didn't have pictures. Is the correct fix for this backer rod and silicone sealant?

Thank you all for your help!
[Hearth.com] Gap between Flue and Crown Clay Piece
 
Hello,

Was measuring up the chimney for caps and noticed a 3/8" to 1/2" gap in the location circled below. I found a couple threads describing situations I believe were similar, but didn't have pictures. Is the correct fix for this backer rod and silicone sealant?

Thank you all for your help!
View attachment 258733
The right way to fix that is to replace the top section of clay, mortaring it to the lower one with refractory mortar. But chances are the other joints aren't good either.
 
I guess I would replace that top section of clay tile when I removed and re-poured the chimney crown.
 
The right way to fix that is to replace the top section of clay, mortaring it to the lower one with refractory mortar. But chances are the other joints aren't good either.
Shoot.. I had the chimney inspected and was quoted to replace the top section as you described. After reading around was hoping the backer rod and caulk was sufficient. What would be a ballpark, fair price for that sort of repair (top section only)?

Thank you for the input!
 
Shoot.. I had the chimney inspected and was quoted to replace the top section as you described. After reading around was hoping the backer rod and caulk was sufficient. What would be a ballpark, fair price for that sort of repair (top section only)?

Thank you for the input!
I wouldn't do it without pouring a new crown. I just don't see that it is possible to get the old clay out without destroying that cracked crown. So total of $1200 or so.
 
I wouldn't do it without pouring a new crown. I just don't see that it is possible to get the old clay out without destroying that cracked crown. So total of $1200 or so.

Thank you bholler. I was quoted $1500 for the repair so will look into getting another quote or two. Really appreciate your quick replies and guidance!
 
What would be a ballpark, fair price for that sort of repair (top section only)?
I wouldn't do it without pouring a new crown. I just don't see that it is possible to get the old clay out without destroying that cracked crown. So total of $1200 or so.
When I got a quote from somebody I thought would be good, it was two or three thousand, so I just did it myself. If you feel like it's something you would tackle, there are a couple threads here about it. Use the forum search (magnifying glass above) and type in "chimney crown repair/replace" or the like, and you should find them.
Lots of junk on youtube, as usual, but there's also a couple good videos..
 
Thank you bholler. I was quoted $1500 for the repair so will look into getting another quote or two. Really appreciate your quick replies and guidance!
$1500 is not out of line. Just make sure who ever does it pours an overhanging slab with expansion joints around the clay liners and a bond break underneath.
 
  • Like
Reactions: Woody Stover
I came across this because I need to seal around my crown to the flue.

Last year I had the crown repoured and the clay joints replaced down lower. The guy was kinda of a schmuck and tried to add on fees once the job was complete, minus him sealing the brick mortar, the crown and sealing around the flue. Now he won't come back to finish it.

So my question is this. I'm going to just do it myself, which I should have done the whole job. The gap around the flue to the crown is kinda large, so I think I need a filler before I silicone. Is there a special backing rod to use? A special silicone? And what type of waterproofing sealer should I use on the crown and mortar joints?

[Hearth.com] Gap between Flue and Crown Clay Piece