CRACK in my arch?

[eprante]

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]

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]

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]

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]

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

[brickie in oz]

Looks like the different expansion rates from the terra cotta flue and the refractory bricks caused the crack to me.

[david s]

Apart from not liking the look of a crack, oh my god my oven is broken? The main problem is that it provides access for water entry from the weather and the resulting problems of having a wet oven. If possible the cracking problems should be reduced, especially by design features.

[Erniegarcia76]

Man, that crack has niching on mine!