Do I have to dig a four foot hole?

[mtorment]

My wife and I are thinking of making a WFO our next big project. We live in PIttsburgh, PA and from what I've been reading I would need a rather thick slab or floating slab to cover the 40". We are only going to live in this house for another two years or so. Any thoughts on a mobile base or another foundation that wouldn't require the work of a large slab? Would I be okay with a 6-8" slab on my soil (since I only anticipate two years of use out of this oven personally") Any help appreciated.

[BeanAnimal]

It really depends on your soil conditions. I too live in Pittsburgh and am deliberating the pros and cons of each foundation type. I have come to the conclusion that due to the soil conditions in my yard, that I will need a full 36+ inch deep foundation. My yard only has about 6" of topsoil and the rest is solid clay. The yard has a good slope to it, but does not drain well due to the lack of permiable soil. I fear a floating slab would shift over the long haul.

2 Years is a somewhat short time. Do you plan on moving to a longer term home on the area? Many of the builds here easily span 12 or more months.

[stormy]

At two years of use, you might want to take it with you if you are moving local. Build the base on a steel frame, use 12x12 treated posts to hold it up. When moving time comes, hire a brick truck with its lift device to move your oven. Most brick yards have flat beds that have a lift truck hanging off the back so the can deliver into the back of properties. Yes-you can take it with you.

[Ken524]

If I were moving in the next 24 months I would buy a pizza stone for my indoor oven and wait until I'm in the next house .

[stwater]

I used a precast, concrete manhole for a base unit - flipped upside down. It does not require footer at all, just solid ground. Simply skin off the sod with a shovel and place a few inches of gravel for this manhole to sit on. You would need a large piece of equipment (large backhoe) to set the manhole; if you can't get this equipment into you yard then this option will not work. This unit could be moved with you when you move, if you have the access to equipment. I live to the north of you in PA - frost is not a problem because the manhole is monolithic so there is no differential settlement.

[Neil2]

"I used a precast, concrete manhole for a base unit"

Sounds like an excellent solution. What were the dimensions of the manhole unit ? Was it just the lid, or was it the barrel as well ?

[stwater]

It is a 4 foot inside diameter, precast manhole with an 8 inch extended base. The manhole walls will be six inches thick, so the outside diameter of the barrel section will be 5 feet. As I said before, the manhole if flipped upside down, so that the extended base is the surface that you build on. It essentially looks like a "big" soup can sitting on a big dinner plate - then you flip it over. I built a 42 inch WFO on this base unit. I would be glad to send you construction photos (I have many) if you like - just give me your email address.

Dwight

[tsuri]

Originally Posted by mtorment

My wife and I are thinking of making a WFO our next big project. We live in PIttsburgh, PA and from what I've been reading I would need a rather thick slab or floating slab to cover the 40". We are only going to live in this house for another two years or so. Any thoughts on a mobile base or another foundation that wouldn't require the work of a large slab? Would I be okay with a 6-8" slab on my soil (since I only anticipate two years of use out of this oven personally") Any help appreciated.

Hi,
just starting to plan a WFO in Pittsburgh (in the city itself). For what I've read up to now you've to go pretty deep, mostly for getting below the frost line. alternatively, there's something called Frost-protected shallow foundations (Frost Protected Shallow Foundations - Oikos) that allow you not to go very deep. I haven't figured it out whether all those concerns apply to something the size of a brick oven, though.

On a side note, I haven't figured out the building codes/permits required for a brick oven. Do you have any pointers? Thanks.

[Lburou]

Originally Posted by stwater

It is a 4 foot inside diameter, precast manhole with an 8 inch extended base. The manhole walls will be six inches thick, so the outside diameter of the barrel section will be 5 feet. As I said before, the manhole if flipped upside down, so that the extended base is the surface that you build on. It essentially looks like a "big" soup can sitting on a big dinner plate - then you flip it over. I built a 42 inch WFO on this base unit. I would be glad to send you construction photos (I have many) if you like - just give me your email address.

Dwight

I, for one, would read a thread containing your build pictures and your story....

[RTflorida]

I'm a former ne Ohio guy, so I can relate to the poor soil drainage throughout the whole region. If you are CERTAIN that you will be leaving, then go with something smaller on a mobile base that you could hopefully take with you. If you think you may be stayng, you have to go all out and do those 3" deep footers, if you don't, you may have a cracked mess when things thaw out next spring. Frost heave can be very detrimental to anything not anchored below the frost line,

RT