Oh, the Humanity!!

[brickie in oz]

Re: Legos & used fire brick have something in common

I plan to make a flared oven entry like the one you made.

Dont make the arch so flat unless you have heaps of buttressing to back up the downwards load.

[Lburou]

Legos & used fire brick have something in common

They are easy to recycle!

I plan to make a flared oven entry like the one you made.

Good luck on the rebuild, and, with life's other trials. :bucketfullofencouragement:

[DaveW]

Re: Oh, the Humanity!!

Yikes! My worst nightmare (regarding pizza ovens). At least yours was not enclosed. I am sure you will have it back up in no time.

dave

[Tscarborough]

Re: Oh, the Humanity!!

If you told the mason what to build, it isn't his deal. I run across this often with fireplaces "designed" by architects. The mason builds it as drawn, and when it doesn't work the architect and GC want to blame the mason because he is an expert at building fireplaces. And he is an expert at BUILDING them, not designing them.

[Tscarborough]

Re: Oh, the Humanity!!

In a static structure, the mortar has such a low required strength that it would probably never have been an issue. It did not remain static. I have seen hundred plus year old buildings where I could literally tear a rock out of the wall with my hands, but the building was structurally fine, although in need of eventual remediation.

[Tman1]

Re: Oh, the Humanity!!

If you paid a mason to do this work, shouldn't he have some responsibility to have done it correctly? I did notice the interior pictures looked quite good (no joints lining up).

[gbohnstedt]

Re: Oh, the Humanity!!

I don't think that the failure of the arch was the sole cause of the failure of the dome. Certainly it did precipitate the collapse, but there was very low bond strength in the mortar. Several days before the crash, I walked around the oven and noted the poor adhesion of the mortar to the bricks (several were loose and moved in place) and found that it would flake off if I dug into it with a fingernail. In fact, I just took another look and much of the mortar crumbles and turns to powder at the touch. One of the rows in the dome simply separated from the brick below it leaving no speck of mortar on the lower row.

On the positive side, it makes cleaning the bricks for reuse quite easy.

Greg

[brickie in oz]

Re: Oh, the Humanity!!

Too much weight on that flat arch with no lateral support caused it to collapse.

[Les]

Re: Oh, the Humanity!!

I don't think you can blame the flared entry..

I agree with this David. It's been done w/ no problems - I wish I had done that. But, mechanically, I can see if the arch was compromised (low arch with no lateral support), with the weight of the flu stack and brick, that it could conceivably pull the rest in with it. Its like when they demo a building - blow the supports and the whole damn thing comes down.

[mklingles]

Re: Oh, the Humanity!!

Oh the humanity indeed. Give us hope. Tell us your going to rebuild!

[Tscarborough]

Re: Oh, the Humanity!!

Note that that is an explanation of the term, not it's applicability to our application. For that, read this:

Reinforced masonry engineering ... - Google Books

[Tscarborough]

Re: Oh, the Humanity!!

The technical term is "saturated surface dry". Here is an explanation:

Concrete Technology | Frequently Asked Questions (FAQs): Saturated Surface Dry | Portland Cement Association (PCA)

The brick should be dampened to some extent depending upon conditions, but never soaked, which would imply saturation.

[waynespizzaworld]

Re: Oh, the Humanity!!

Sorry Greg to see and hear here what happened to your oven. I hope this doesn't high jack this post but I have a question on an earlier comment that I may have miss understood....
"Doing things like soaking the highly absorptive firebrick and mixing the mortar somewhat wet for workability and potlife decrease bond strength and should be avoided."

I am thinking to when I built my first oven I soaked my bricks before cutting and mortaring them in place as I thought this was to help stop the bricks from drying out the mortar too quickly. I am I just reading into the quote here wrongly and the advise is for something else regarding moisture and brick.....Its been 2 years since I have thought about details of the oven build but I am now in the middle of planning another build and just want to make sure I am on the right track..........wayne

[Tscarborough]

Re: Oh, the Humanity!!

Defiantly keep warning them off the wet pre-mix. It is not suitable for a Pompeii style oven.

It wasn't the design of the entry itself that failed, it was the lack of buttressing for the low arch.

[dmun]

Re: Oh, the Humanity!!

Is this a first? Has an oven (other than the wet clay geodesic at MFA) ever collapsed before?

I don't think you can blame the flared entry. I have one and there seems to be no danger of collapse (so far).

I think I can safely keep warning builders off of wet premix mortars.