Longmont, CO new WFO build - casted over sand

[cnegrelli]

Glad I asked!

[david s]

It is far easier to build the dome on top of the firebrick floor. Any floor brick that cracks orneeds replacing will be in the middle not at the perimeter. You can then easily trim any floorbricks that extend past the dome after you've finished the dome casting.

[cnegrelli]

Concrete top of stand is now curing. Moving on to next phase and I plan to have the dome rest on either the insulation layers or firebrick, so as not to have the dome in contact with the concrete (heat sink).
Planning to use the same FoamGlas, CalSil sandwich as UtahBeehiver but I will be casting my dome on sand, not building from firebrick.

Build on firebrick or on CalSil board? Firebricks would then be on inside of dome walls, so they could be replaced/removed? Opinions?

[agrasyuk]

Weather is indeed quite a bit of a factor in this. Good luck on the pour, make sure your concrete is not to watery (thats a lesson to myself).

[cnegrelli]

Ready to pour if the thundershowers pass on.

[cnegrelli]

I went ahead and filled them this morning. I had planned on 10 bags of 60lb concrete and it took 9.5! Decided I wanted to be sure that the corners of the dry stack was anchored solid before I started loading it down with the hearth.

[david s]

Standard (8") blocks take 3 litres per core. If you use 6" blocks it's 2 litres per core.

[Toomulla]

from memory you need 1 cubic meter to fill 120 blocks, if you use a 10 mm concrete mix you should not have any problem soak the blocks prior to filling

[RandyJ]

The only issue I can see would be trying to keep the rebar centered in the core. make sure that you fully support the slab with a frame work as that will be what is holding the wet concrete up. Just remember it takes a fair amount to fill the cores. Make sure you have enough to do the whole job.

Randy

[cnegrelli]

Question: Is there any reason that I cannot fill the CMUs (all 8 with rebar) at the same time that I pour the slab? I'm doing a monolithic slab form. Seems like its more efficient, but I don't recall anyone doing it in one step.

[cnegrelli]

It has begun.... And so have the rains, almost every day right now.

[Damer419]

Bummer about the grill, but the WFO is the main attraction............Enjoy the build

[cnegrelli]

Long story, but the Santa Maria Grill has been put on hold. It may come back in the picture later, but there was a complication with having to do a 2nd slab, and how that would fit. Made decision last night, to get moving on the WFO. CMUs and 60# concrete bags expected tomorrow. Ready to start the dry stack and drilling in rebar.

[cnegrelli]

So I've been a bit on hold for awhile while the HOA endlessly debates my build. I got approval today, but cannot do a stucco finish. They were not clear about the oven itself, and didn't really ask about the oven appearance, so I'll worry about that later. I'm told they will never come back to inspect it and my neighbor behind me who can see it isn't going to complain as long as I feed him pizzas. But I needed approval as the lady across the street would freak-out when the concrete and block arrives, if I didn't have HOA approval.

Got 7" of very heavy and wet snow Thursday/Friday, so spent most of today cutting up branches which I've stowed away for drying (mostly Maple). I've got some Apple and Cherry, plus Aspen. All will be useful at least in curing (plus I have a bunch of Lump Charcoal I use for my homemade Big Green Egg).

I've started to dig out for a small 40"x40" pad that will hold the Santa Maria Grill I've decided to do. Rather than go go real deep to assure I'm below frost, my architect buddy told me to build it exactly as that of the pad that will hold the WFO. If there's some heave, it's best to have them both floating. He told me today that while my hottub was indeed very heavy, it was a uniform load. So I'm rethinking a bit how I orient the oven, but plan to make it very well supported and well distributed on the pad.

[david s]

You will have plenty of thermal mass with 2" ofinner dome thickness. With a small oven the heat loss is greater at the door because the door is a bigger proportion of the oven surface. My feeling is that 4.5" of blanket won't give you any advantage over 3" as the insulation is subject to the law of diminishing returns. Remember also that a layer of 10:1 vermicrete over the blanket also provides good insulation.