Concrete slab recipe

Been down to my local garden center and he says the mix is 4:2:1 , thts 4 sand to 2 aggregrate to 1 cement.

I got a quote from a "mini-mix" delivery and its was $226 for my .4Msq , the cost of the sand/aggregate/cement from the local bloke is $129 !!! why the difference, WELL he tells me you can order what you want of the mini-mix but they just charge you a MIN 1Msq.

It doesn't matter when or where you are reading this but almost double is a BIG difference, especially when you can find sand and rocks everywhere yourself !

Everything I read still says "portland cement" is an ingredient you need, portland NOT becuase its from portland its just the brand/type name. it has certain attributes and probably best just buying the stuff ! but if you want to spend time researching then "portland cement" is where to start.

Gonna go do me some sand hunting LOL

Ready to start

Well today I delivered the last of the big items to granma's to start building the project, it was the last of the solid bricks, some wood to make the surrounds for the slabs, the angled bricks i got cut and a few pieces of "metal cross reinforcing" for the extension to the roof above the oven.

We are heading into winter so as expected this will slow up the project but at least no more "hunting and gathering" and "delivering" .

except now the concrete and mortars !

Added extras

SOO much info so far and I still haven't started ! well half the reason is by writing the blog i reaffrim ideas into my own head so it helps me greatly.

Just saw a professional restuarant smoker oven on telly, what it had was sliding racks on rollers thus just like an oven grill. great idea to make it easier to load and unload...I work on the logistics and post it.

ALSO thsu i thought that sometimes you may want all racks in or just one? depending on the size of what you are smoking, thus i thought it would be a good idea to install some hooks into the bricks of the oven wall for rack storage when not in use.

Support 4 with images

Here are the mockup images

This is a view from the top, as mentioned previously I will have 2 levels of sideways bricks for the oven to sit on , the same will be on the other side of the structure.

From the outside the bricks look like this, remember this is just a mockup so i didn't spend to much time on it.

Close up view, i think this is a much better solution then building an internal stack of bricks

how to lay a concrete slab

here it is , this is really perfect instructions with great tips

http://www.youtube.com/watch?v=HQafafOwBT0

Making smoke go UP

One concern for me is that the smoke actually goes where i want it to.

First we have it coming out of the dutch-oven and rising into the bottom vent of the oven where it will fill the oven and then go out the chimney....we hope.

My oven has the bottom vent right below the chimney area??? you know how a gas oven has the flame at the back well thats what i have, now it might be ok for HEAT to rise quickly into an oven but i think smoke is a little lazier, i might have to create a curved hood to make sure the smoke doesn't just go up into the oven and STRAIGHT into the chimney and disappear.

thankfully this is something I can test long before i put it into the brick structure and thats why I wrote this piece as I would strongly suggest you all do this before commiting the oven into the space as playing with it afterwards would be a hassle.

One thing I do like about the fact the incoming vent is at the back is that any drippings from the food can be caught on a tray and NOT end up on the element which would happen if the hole was in the middle of the oven.

Supporting the oven 3

I think i've worked out what to do with supporting the oven on bricks.

I will create the side brick walls VERY close to the ovens sides, then when i get to the correct height I will turn bricks around/sideways to create a shelf for the oven to sit on, the weight of the bricks above forcing down on the sideways bricks will keep it stable, if i do 2 layers of bricks intersecting then the weight of the oven + food will be spread over a large area, I think i will also include a piece of reo across the void at the back .

because the oven i have has a draw under the oven door of @ 20cm i will be taking this out and the frame will be left, i'm going to cut the front bottom piece off so its open for the dutchoven and thus the oven will be supported by the side-frames. THUS this sideways brick idea will happen 2 bricks up the element area. (the element will still need to be supported by a brick platform

this method will save a few bricks (@ 32+ eg: [8x4] for the 4 corners) and it will allow for extra side ventilation.