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**splatgirl** · 06-17-2010, 06:49 PM

Re: CRACK in my arch?

Eh. Mine has a WAY bigger crack than that.
As Jay would say "bake on"

**lwood** · 06-18-2010, 07:41 AM

Re: CRACK in my arch?

Don't worry about it, maybe a little heatstop or refractory mortar, to fill in the crack if it bothers you.

**texassourdough** · 06-18-2010, 07:44 AM

Re: CRACK in my arch?

To paraphrase Hogan in Crocodile Dundee....

You call that a crack! I'll show you a crack!!!!!

....ovens always have differential expansion and I doubt anyone has an oven long without developing a crack of some kind.

Fire On!
Jay

**Pdiff** · 06-18-2010, 01:33 PM

Re: CRACK in my arch?

Ok, I'll be the nay sayer here. Watch that you don't get a corresponding crack on the other side of the arch. That's what happened with me. I let it go and eventually the middle section was completely loose. The problem was, when I fired it would expand and the loose center section would slip slightly down. After many fires, this began to act as a wedge, slowly driving the arch and supporting opening walls out. Cracks developed in the side walls and they started to splay out. I had to rip out the whole entryway-vent structure and rebuild. I made the side walls much thicker this time and did a slow wet cure. Unfortunately,the crack has come again, but only on one side. Still, it make me nervous. If things get worse, Ill cut it out and remortor that section.

**Loafin** · 06-18-2010, 03:32 PM

Re: CRACK in my arch?

Thanks for the heads up!

**david s** · 06-19-2010, 12:36 AM

Re: CRACK in my arch?

I believe that cracks in the arch are due to temp differential ie hot on inside and cold on outside. This problem can be reduced enormously by simply having a small gap between the outer arch and the inner parts of the oven. It can be an air gap or filled with vermicrete.It also has the advantage of keeping the outer arch cooler and therefore safer, to touch. The heat loss through conduction is also lowered.

**Eric Pfeifer** · 06-19-2010, 11:21 AM

Re: CRACK in my arch?

I think anyone who builds a brick oven needs to make inner peace with cracks, and assume that from time to time, minor repair will be necessary.

**texassourdough** · 06-19-2010, 11:31 AM

Re: CRACK in my arch?

Well said Eric! Part of the good news is that after building the oven I think many/most of us have the skills necessary for those repairs!

Eat more Pie (pizza that is!)
Jay

**Neil2** · 06-19-2010, 05:15 PM

Re: CRACK in my arch?

Mortar layer between arch bricks is too thick. Try for about 1/64 th of an inch or less.

**eprante** · 06-19-2010, 09:42 PM

Re: CRACK in my arch?

1/64 of an inch? Neil what are you mixing your mortar with, talcum powder? How do you get a joint that small
Eric

**Neil2** · 06-20-2010, 11:51 AM

Re: CRACK in my arch?

Well. As thin as possible then. Mortar is not a "glue" in compression structures such as arches. It's only function is to transfer the load evenly from one face to the next.

**tmarsala** · 06-22-2010, 03:18 PM

Re: CRACK in my arch?

Hi, all-

I need some advice. The top three bricks of my entry arch (including the keystone) into the dome have come loose. After fire up, they are rocking as I put the door in to retain heat for the week. I am wondering if anyone has had a similar problem and has had to R&R any part of their arch? Should I leave it alone until the bricks fall? Or should I remove them and re-mortar them in place? This is my 8-th large fire-up after curing.

Tom
Menifee. CA

**130mountainside** · 07-01-2010, 05:16 PM

Re: CRACK in my arch?

Cracks....fired up the oven on schedule....8 fires, all good. 9th fire, fired it up good and long...cracks galore..no smoke escapes however....I guess I just have to hang in there until the bricks or mortor get loose? Comments?

**tmarsala** · 07-01-2010, 08:35 PM

Re: CRACK in my arch?

Hi-

I think cracks (especially in the mortar joints) are totally OK-the oven needs a place to move around and those cracks provides some good expansion room.

Each time I fire, the arch bricks get tight again, so I think that they need to just hang loose cool so that they can have room to move in the heat.

I know we tend to think that the whole thing will come down at some point, but I really think that these ovens will outlast us!

Fire on and long (I fired mine for 6 hours today and it was fun!)

Are your bricks cracking, or just your mortar joints?

Tom