How to WFO's fare in earthquake country?

[Paul_H]

Not sure if this is the correct forum to post in, but I see quite a few members in CA and wanted to know if anyone has input on how a WFO will fair in an earthquake? I grew up in CA and lived about 50 miles from the epicenter of the Loma Prieta quake at the time. That said, Alaska is an order of magnitude more seismicly active. 4.0-4.5 quakes are just about a given at least once a year, and I have no doubt in the next 10-20 years we'll have something between 5.0 and 6.0.

I don't want to build something that will withstand every possible quake scenario, but I'd hate to put 1000's of dollars and 100's of hours of effort into building a stove and have it damaged to a the point it would need to be replaced within a couple years of completing it.

[Tscarborough]

Re: How to WFO's fare in earthquake country?

If you build it to the Forno Bravo plans, you can use it for a shelter in case of an earthquake.

[Paul_H]

Re: How to WFO's fare in earthquake country?

I don't know what you're experience is with earthquakes, but masonary structures tend not to fair well in them. I'm sure the base support with rebar reinforced concrete would do well, but unless I'm missing something the dome does not have such a support and I would imagine strong lateral loads could do a number on the dome.

[Tscarborough]

Re: How to WFO's fare in earthquake country?

It is a dome.....

[stonecutter]

Re: How to WFO's fare in earthquake country?

What exactly are you looking for? For the most part, everyone on here is an amateur mason, and has zero experience building masonry structures built to seismic code, using the components used in those types of structures. The number 1 reason is because it's not necessary.

To be honest, there isn't much you can do different than what the plans call for, and that's is probably why you got the recommendation to build to the FB spec.

[Paul_H]

Re: How to WFO's fare in earthquake country?

I'm not looking for a specific code to build to, I'm just wondering if anyone who has built a WFO has had issues with it being damaged by a moderate earthquake. As far as need, certainly I don't need to build an outside oven to such a code, but again I'd hate to put 1000's of dollars and hundreds of hours into a project I plan to enjoy for upwards of 20 years if it will be damaged by a moderate earthquake which I know for a fact it will be exposed to several times in that 20 year time frame.

That and I'm debating building a brick oven vs. purchasing a FB kit with a cast refractory dome. I'm trying to figure out where the value of my time offsets the added purchase price of a dome, and if a cast dome would fare better in an earthquake then that would further lean me in that direction. However I've read several threads where people have had issues with cracks with the kits so I'm a bit hesitant to plunk down the coin if I can build a more durable dome myself.

As far as there being nothing one could do, well a support structure that has some flex and can isolate some of the lateral loads would certainly help. Perhaps I'm completely over thinking it as if the domes can survive being bounced around on a trailer or catering truck they should be able to handle the occasional moderate quake.

[stonecutter]

Re: How to WFO's fare in earthquake country?

. Perhaps I'm completely over thinking it as if the domes can survive being bounced around on a trailer.....

I think you hit the nail on the head here...but you are in like company.

If an earthquake shook a unitary dome apart, at least you still have the material to work with, and they are fairly easy to rebuild. It's the surrounding structure (enclosure) that would be a hassle to rebuild, depending on how elaborate you went with it.

[Tscarborough]

Re: How to WFO's fare in earthquake country?

UN-reinforced masonry is horrible in earthquakes, but reinforced masonry fares well. The thing about unitary masonry is that all of the cracks are pre-engineered, and overall allow for a fair amount of flexural strength. A dome is inherently stable, and able to withstand vertical and lateral loads. A cast dome is as well, but if it does crack it may cause the structure to collapse, while the unitary masonry dome would not.

[Paul_H]

Re: How to WFO's fare in earthquake country?

I appreciate the input and hope I wasn't being argumentative. I'm just trying to figure out what I should be worried with and what I shouldn't. I think my bigger concern will be properly prepping the are I'll be building the outdoor kitchen so I don't have issue with frost heaves and jacking.

After getting an online quote to crate and ship a FB Premio 2G110 and finding that would add 50% to the cost of the kit my decision is made on fire brick over a cast dome. I figure with the money I'll save it'll pay for Komado grill, pizza stone and a couple year supply of pizza ingredients and beer.

[Toomulla]

Re: How to WFO's fare in earthquake country?

If you have been through an earthquake bad enough to wreck your dome I expect that will be the least of your problems

[stonecutter]

Re: How to WFO's fare in earthquake country?

From what I have seen of frost depth code in AK ( up to 10') I think you would be better off with a thick (12") double rebar grid floating slab on 6"-8" of 3/4" crushed stone....if you are going to build an oven.


Also, if it was me, I would not hesitate to build one on a timber stand. Especially if you didn't want to build a reinforced masonry base - a mortared, bonded cmu stand with grouted, reinforced cells. A timber stand would most likely absorb and distribute mild tremor activity as well as the heavy masonry base, and it probably has greater tensile strength.

[GianniFocaccia]

Re: How to WFO's fare in earthquake country?

Having grown up in earthquake country, I have experienced dozens of 5.0+ quakes and two 7.0+ quakes. It's only a matter of time before we'll get hit again and be able to assess the quake-worthiness of our ovens. Last week's mag 4.4 (epicenter 30 mi from here) was negligible.

I'm sure the Pompeiians (5 mi from Vesuvius) experienced a regular diet of tremors yet even today, its probable they have more ovens than we ever will.

[stonecutter]

Re: How to WFO's fare in earthquake country?

I'm sure the Pompeiians (5 mi from Vesuvius) experienced a regular diet of tremors yet even today, its probable they have more ovens than we ever will.

True, but those mass based ovens have tons of masonry to absorb the shock, and these ovens don't.

Having said that, I think most ovens ( the whole structure...not just the dome itself) on here would hold up reasonably well, the way that they built.

[Wiley]

Re: How to WFO's fare in earthquake country?

Paul H. My folks lived off Summit Road and had several neighbor's homes destroyed in that quake.

Where I presently live earthquakes are an issue and the powers that be tell us a significant quake is in our future. I built my WFO on the basis (hope/expectation) of having it survive such an event. As for having its survival be the least of my worries rather I would counter that it is significant in my survival plans. If we learn anything from Katrina or any of the storms of just this past winter in any natural disaster of any consequence the quality of ones existence after the event will be due to what planning and preparedness one creates beforehand. One can expect the gov't to prioritize their response according to most bang for the buck. If one lives in a somewhat remote area, as I do...a small island of about 1000 individuals, one cannot expect to get the attention given to Seattle or any other major population area.

This could easily get well off subject but you might consider something akin to my Steel Dome Oven if survivability of an earthquake is important to you.

Hope this helps,
Wiley

[Paul_H]

Re: How to WFO's fare in earthquake country?

I appreciate everyone's input. I'm not looking for an oven that will survive every possible quake, but figure for the expense and effort of building it, it should should survive the moderate tremblers it'll certainly be exposed to over.

Stonecutter,

I appreciate the input and after I excavate and level the area I'll probably put down a base of 12" of gravel. Trucks deliver 10yd loads, so depending on the size of the pad I'll be getting 10 or 20 yds of gravel and would rather have a bit more, than a bit less. During the spring melt, there will definately be water flowing over that area. Even though it's still under a foot or two of snow, we're already getting some melting and I saw some water nearby where I have my wood stacked. I also like the idea of an extra thick concrete pad, more for being able to deal with some settling w/o cracking.

Wiley,

Even though we're building in a subdivision in town, we're trying to add as much self sufficiency as possible. We'll have our own, backup power, wood stove, and eventually a greenhouse, small garden and an outdoor cooking area. Pretty much everything in Alaska is shipped in via Bellingham Washington, so a disruption to either the ports in AK or Northern Washington would have an effect on us. And even asside for a large natural disaster, the area we're building faces hurricane force winds annually, roads that can get so iced up you really shouldn't be driving on them for a day or until they lay down gravel, and power outages for somewhere between a day to nearly a week when the winds or ice knock down the power lines.