Cracked chimney flue Pompeii Oven Construction Discuss Cracked chimney flue in the Pizza Oven Design and Installation forums; After a long winter, I'm back at it. I took the tarp off to inspect the oven. It seemed fine, ...

[mfiore]

After a long winter, I'm back at it. I took the tarp off to inspect the oven. It seemed fine, but when putting the tarp on, noted that the clay chimney flue liner moved a tiny bit.

I had used a previously described method to make a tapered flue (see photo).

Used HeatStop for to bond the flue. I also set it into a bed of heatstop to set onto the arch. Seemed fine the few times I've used it. I thought I'd repair before moving on. The flue could easily be lifted off. The heat stop crumbled away, which it hadn't done for all the dome (rock hard). As I took it off, the flue separated in two pieces. Seems the mortar didn't bond with the clay.

Should I pursue a different vent system? Any reason the mortar shouldn't bond with the clay flue liner? Anyone else have problems? If your chimney is built and the flue liner covered, you may not know it's cracked I suppose.

[Les]

Mike - we both went a similar route on the vent. I haven't noticed a problem with mine, but then again, its covered. After I covered my vent pipe with decorative brick, I filled the gap in with portland/vermiculite. That may be the reason I am not seeing any separation.

Good luck!

Les...