Dome cracks

[james]

Here's my two cents on oventhusiast's cracks.

I think we all do everything we can to minimize the chance of cracks, including high quality bricks, good quality mortar, making sure our bricks are wet during construction, slow mortar curing times, slow oven curing fires, etc. You do your best, but sometimes brick ovens just crack. We're working with heavy mass and big temperature variation, so we're fighting nature.

Even Mr. Becuzzi, the artisan who makes the Artigiano ovens, basically says the same thing. It doesn't impact how well your oven will cook, or how long it will last.

What does everyone think?
James

[gjbingham]

I agree with James. I see posts about replacing bricks in the floor of the oven if they crack. I can't see any reason for this. They still absorb and hold heat as though they were whole. Replacing them for a new unbroken brick seems lake a waste of time.

Same same for a dome. I can see wanting to fix the stucco, but I think all and all, the cracks will have very little effect on the ability of the oven to cook food, which is what we are building them for.

That's my guess.

[Frances]

That sounds really good to me. After all the insulation is what holds the heat in, and as long as the dome doesn't actually fall down...

The ovens some of you are building are so impressive, but they can be a bit intimidating to less skilled builders. So thanks James for posting this thread. Cracks are not the end of the world (or the oven).

[oventhusiast]

Thanks James, and everyone else who replied about the dome cracks. I know it's almost impossible for a dome to not get some cracks in it, with all the expansion and contraction going on. I just was wondering if the cracks I realized on my dome seem small, normal, or excessive by other peoples experiences ? Also, do I 'need' to parge coat my dome with more heat stop if I'm going to cover it with a 'dog house'? And is one box of Insulfrax enough? I plan on using at least six inches of vermiculite over the Insulfrax.
Rick

[james]

Hi Rick,

You might want to coat the exterior where you have the hairline cracks -- at least if you have some mortar already on-site. Use what you have.

Then, you are ready for the Insulfrax -- one box will do it. That, plus 6" of vermiculite will do a very good job.

James

[Bacterium]

Cracks in the outer stucco (render) layer have had me thinking lately .....has anyone here applied a clear weatherproof coating to the exposed stucco layer to help stop mould or mildew on the outside? You know to keep the stucco looking nice and new over the years

I was thinking of trying something like they use for sealing pavers, concrete, etc. a benefit might be that if applied thick enough it could also dribble into the outer hairline cracks, effectively sealing them stopping mositure entry under the stucco.......sure no big deal to the oven function....but hey could my theory work?

....yes I have a couple cracks.....ok I am nearly over them

[Ageo308]

Hi guys, we have noticed a couple of hairline cracks in the dome which is from the cement render. My dad is going to put another coat ontop which should hide them (not real noticeable anyway).

Unless they are large cracks i wouldnt worry too much.