Wisconsin Considerations

[manumit]

Re: Wisconsin Considerations

I appreciate all the advice. I certainly won't be uninformed when I make the decision.

[mrchipster]

Re: Wisconsin Considerations

Great solution! Build a 24'x30' slab as a base for your pizza oven and you won't have to worry about it! Not!!!
So go ahead and float a slab for your oven, then next year you want something else attached to your oven--like a BBQ! or whatever! Then all these little slabs can frost heave anywhere they want to!
Start off with a half ask job and that is what you will have when it is done! But that is only my 2 cents! Argh!!

I agree, if you are going to connect the oven to any other structure in the future build a proper footing it is not that much extra work (especially in sand) and the cost is only about an extra 100-150 dollars in materials and if you do not count the time to dig the hole as a cost. It is the safest way to go.

[mikku]

Re: Wisconsin Considerations

Great solution! Build a 24'x30' slab as a base for your pizza oven and you won't have to worry about it! Not!!!
So go ahead and float a slab for your oven, then next year you want something else attached to your oven--like a BBQ! or whatever! Then all these little slabs can frost heave anywhere they want to!
Start off with a half ask job and that is what you will have when it is done! But that is only my 2 cents! Argh!!

[NCMan]

Re: Wisconsin Considerations

Frost heave of a foot is crazy.

My soil is sand, more sand, and then rocky sand. The top few inches give a pretense of a dirty color, but really it's just sand. I'm going to do a slab and go from there. When I moved into my house someone had tried to build a hideous cinder block grill poured on a small slab in the yard. It had been there for ages and was still level. The construction was of such quality that I took the whole thing out with a sledgehammer, slab included, and it had no cracks or stability problems.

I think I'll forgo the frost level foundation.

If you go that route, at least thicken the edges as much as you can, use rebar and pay particular attention to keeping the edges backfilled as high as possible, especially on the west and north sides, as well as edges of the slab that are exposed to the cold winds. These suggestions are just to help, not totally prevent, frost heave. Also, when discussing having seen slabs w/no frost footing, etc., remember that some slabs are well protected from the severe cold and wind, as well as the direction of said exposure. There are numerous factors to consider, such as soil types, moisture, etc. You can't just paint them all w/a wide brush. Lots of slabs do lift up and simply go back down and people don't even know it happens. Exposure means a lot. That is quite an investment you are making. I suggest doing what you can to at least lessen the chance of severe frost heave and permanent damage. This is not what I would do, but since you have expressed your plan to forgo the frost footing, you might consider these tips. I've seen firsthand what frost can do. My 2?.

[NCMan]

Re: Wisconsin Considerations

The reason we dig footers down to below frost level in the great white north is to keep the structure stable.

I always recommend to put in the footer cause there is no way I'm standing behind a tilted slab after a cold winter. Frost can and will get under the slab and if you cheat on the slab design, you can split your oven in half.
The whole sonotube thing is an absolute joke, just take $200 out of your wallet and light it on fire...you have the same result as digging in sonotube with the additional bonus of enjoying a nice cozy fire for 12 seconds.

Well said and the absolute truth.

[dakzaag]

Re: Wisconsin Considerations

The reason we dig footers down to below frost level in the great white north is to keep the structure stable. Frost can and will move some fairly heavy slabs if it gets the chance. Some area's with a lot of sand will never freeze, even in N. Wisconsin. I live on heavy clay in NW Indiana, I have a full basement.

When you are building your own oven and are willing to take the risk that it might move after a nasty winter, it is your choice. If it moves as one unit and ends up being out of level by an eighth inch, no one will ever know. If it moves an inch and doesn't go back down, you are going to feel pretty stupid cause the fix at that point gets a lil 'spensive.

I always recommend to put in the footer cause there is no way I'm standing behind a tilted slab after a cold winter. Frost can and will get under the slab and if you cheat on the slab design, you can split your oven in half. Most of the time the slab will heave and then go back down where it started from.
Another option for those who don't want to dig is to use landscape block as the base. These block are designed to move with the frost and not be damaged. I have a small planter area at the front corner of my house that I rebuild about every year cause the soil pushes it over. No big deal. The challenging part is placing a really heavy solid slab and oven on top of the stacked block. During this time of year, one corner can get really soft and the whole thing tilt. Then your looking at a rebuild.
So the choice is yours, and I respect the guys who dig in footers and I understand the guys who don't. I won't try to sell slab on grade cause it is not a risk I am willing to take. If you sign a paper stating you understand the risks, I will gladly build you a 5 ton oven in a swamp with tooth picks for a foundation.
The whole sonotube thing is an absolute joke, just take $200 out of your wallet and light it on fire...you have the same result as digging in sonotube with the additional bonus of enjoying a nice cozy fire for 12 seconds.

[manumit]

Re: Wisconsin Considerations

Frost heave of a foot is crazy.

My soil is sand, more sand, and then rocky sand. The top few inches give a pretense of a dirty color, but really it's just sand. I'm going to do a slab and go from there. When I moved into my house someone had tried to build a hideous cinder block grill poured on a small slab in the yard. It had been there for ages and was still level. The construction was of such quality that I took the whole thing out with a sledgehammer, slab included, and it had no cracks or stability problems.

I think I'll forgo the frost level foundation.

[RandyJ]

Re: Wisconsin Considerations

I will say this about building in a area where there is frost. If you have a lot of clay you can end up depending on moisture level with a ton of frost heave. My brother in law bought a house that someone did not put the post footings for the deck down far enough and it has been known in wet years to heave almost a foot in one winter, but that is in an area of very heavy clay. But like chip my 24x24 garage is slab on grade and 40 years old and no issues at all. I think no small part of that is that as my dad says where we are at it is sand from here to hell.

Randy

[mrchipster]

Re: Wisconsin Considerations

As long as your oven is not attached to any other structures and you are on sand and you make the structure a unit with rebar you should not have any major issues.

My garage is 30 x 24 on a slab in minneapolis and is stable. Properly reinforced with rebar structures will move as a single unit.

[Campmaki]

Re: Wisconsin Considerations

Hello, Just thought I would chime in with a penny or two worth. Sand well drained, clay, whatever kind of ground you have, it is not worth the time and or money to build without getting below the frost line. Over time your structure will suffer because of it. The slab, thickened on the edges or not will move up and down and be compromised by the frost. Do not be fooled, you can not control it, as you can not control cracking in concrete 100 percent. If your structure starts to move, what are your recourses? This movement will them move to the oven and elsewhere in the build.

[RandyJ]

Re: Wisconsin Considerations

Ok good to hear. I agree with you completely. I also just got news that I do not need a permit. Kinda surprised by that but happy. Just makes everything simpler. Now just waiting for a call back from the fire chief about setbacks and I am good to go.

Randy

[manumit]

Re: Wisconsin Considerations

He said to float it on grade. Our soil is all sand and according to him our, "black dirt isn't even dirt, it's just black dirty sand." He then proceeded to recommend the exact same slab layout as the fornobravo guide does, rebar around the outside with mesh in it.

I'm aware that pouring a 4-5 foot deep footing would probably make the thing secure until the second coming and give me ample peace of mind, but I'll probably settle for less peace of mind. It seems like too much work to me.

[RandyJ]

Re: Wisconsin Considerations

So what did your local guy have to say? I am in the same place, and am about ready to start. My plan is probably to do slab on grade but have not decided. If I was to go so deep as to do real footings why not just poor the whole thing solid. At least then you could get a truck to deliver it. If you are in all sand like me I don't think it is going to be a worth the extra work

[manumit]

Re: Wisconsin Considerations

Thanks for the opinions. I talked with a local construction guy I know yesterday and got the 'local' opinion. Not sure what I'll do yet, but I'm starting to feel a bit more informed.

[mikku]

Re: Wisconsin Considerations

Really no short cuts to making a good foundation. Get your footings below frost line and be done with it. Then you will have the peace of mind you started right. Sonotube alone is a fake, add bigfoot type bases and you have the real thing. But excavating for bigfoot type bases OR a standard foundation takes the same time..so no advantage. Detached structures refer to garages etc. with a larger footprint. Expensive ovens deserve a proper base, but that is only my humble opinion for free. So TIFWIW?