Archive for Downsizer For an ethical approach to consumption
 


       Downsizer Forum Index -> Make Your Own/DIY
tahir

Pizza Oven DIY

We're getting ready for sorting out the back patio, this will mean putting some gabions in to hold back the bank.

Plan is to create a level concrete base on top of the gabions (maybe using the top of the gabions as reinforcement), and then build the oven off the top of that.

Any problems with that? Also what sort of size do we need to allow for? I guess we'll use mostly for entertaining; a small gathering is 30 for us, we'll be feeding 130 this bonfire night. I don't anticipate making 130 pizzas in one event but 50 pizzas, partathas or naans is quite possible.
Nick

Honestly, mine will make a couple of decent size pizzas at a time, taking around 5-6 minutes each. Takes a couple of hours to get to temperature.

If I wanted to cook 50, I'd wonder if 2 decent size ones might be the way forward, rather than a huge one, otherwise, when it's just the 5 of you, you'll use a small forest to get it running, and have to wait 5 hours.

I see no issue building on the gabions, though.

Crucial issue, I'm led to believe is the ratio of the door size to the main oven, to allow sufficient air flow v heat loss. I built mine, honestly, around the size of door I was able to buy on eBay.
sean

I reckon two or three sensible sized ones is the way to go. Then you could be using them for different things too. Slow roasting in one and breads and stuff in the others. Plus your patio would look like a puglian model village.

tahir

I reckon two or three sensible sized ones is the way to go. Then you could be using them for different things too. Slow roasting in one and breads and stuff in the others. Plus your patio would look like a puglian model village.



I think we could do that Smile
tahir

I built mine, honestly, around the size of door I was able to buy on eBay.


What's it made of?
tahir

Crucial issue, I'm led to believe is the ratio of the door size to the main oven, to allow sufficient air flow v heat loss. I built mine, honestly, around the size of door I was able to buy on eBay.

Actually sizes of door opening and oven would be handy...
Nick

My door is cast iron, from an old oven/stove type thing.

I have a concrete base, with steel to strengthen it, but I'm spanning brick pillars, on top of gabions, I wouldn't bother with the steel. On top of that is a layer of fire bricks laid on mortar, but just butted up, no mortar between them to act as the base of the oven. Any slight seams or ridges were ground out to make it flat as possible. These hold heat and make sure you get a dry, crispy base. First couple of bakes have grit/dust in them, but that's fine.

The dome is made from more fire bricks, about 4 inches thick, held with normal mortar. I cut with an angle grinder, and filled gaps with mortar; it's not pretty.

Then, an inch of kiln blanket was placed over the whole affair, and a couple of inches of regular concrete mixed with vermiculite to provide further insulation, and a final skim coat of concrete to attempt to weather proof it.

Chimney is a couple of lengths of waste pipe, because I had it kicking about.

I would suggest you use fire cement, not regular, as mine already has some cracks. I don't think it'll matter much, but I'd prefer it didn't.

All my 'fire bricks' are actually blocks from night storage heaters, because they're designed to absorb heat, and emit it over a long period. All culled from eBay for a few pence each. Whatever you use, it's going to be about 5 times heavier than you expect. Smile
Nick

Crucial issue, I'm led to believe is the ratio of the door size to the main oven, to allow sufficient air flow v heat loss. I built mine, honestly, around the size of door I was able to buy on eBay.

Actually sizes of door opening and oven would be handy...

Bear with...
tahir

Ta luv Smile tahir

it's going to be about 5 times heavier than you expect. Smile

I'm not expecting to move it...
Nick

https://www.fornobravo.com/pompeii-oven/pompeii-oven-plans/
http://forum.downsizer.net/viewtopic.php?t=54991&postdays=0&postorder=asc&highlight=pizza&start=0
http://www.ebay.co.uk/itm/Large-Quantity-of-Used-Clean-Night-Storage-Heater-bricks-only-25p-each-/191735803686?hash=item2ca4582f26:g:xXIAAOSwo6lWQki2
Nick

it's going to be about 5 times heavier than you expect. Smile

I'm not expecting to move it...

You will, probably three times. Brick by brick. Once into the car, once out of the car, and once onto the oven structure as you build it.
dpack

there might be an issue with the gabions in that they are flexible and settle over time/creep a bit if loaded from one side.depending on the size ,angle and make up of the slope this creep is a variable.
i might be inclined to dig a trench and part bury the outside line of gabions to reduce side slip and use a rammer to stuff them tight before laying a floor and adding heavy things on top.some rebar driven into the subsoil so as the ends poke up with the empty gabions put on top will help to reduce side creep.rebar into the gabion fill with mesh on top would be good for the floor slab stability as well
wet clay is remarkably fluid and there will be a lot of weight on top as well as the sideways force so letting things settle between the gabion stage and building the patio/ovens over a winter might be a good idea.

ps running the digger (or even a big vibrating roller) over the cleared area a few times will help to compact the subsoil

i know that seems a lot of faff but i have seen quite a few unstable so called stabilised slopes,especially clay ones and overdoing it a bit to start is far better than trying to mend a wonky one.the moderate extra cost at the build stage should prevent any very expensive long term problems.

re the oven perhaps a big one for entertaining and a family sized one would be a good combo .a tandoor /bbq ,boiling,warming rack might be a nice addition to the oven combo patio and an awning over the lot to prevent the kit or the chef getting wet is a good idea.

i got a big second hand super strong stainless steel prep table for about 100 and such a thing would be a very useful addition to an outside event catering kitchen,easy clean,heat proof for bake trays etc etc and can double as a serving table.
Nick

If I had a long run of gabions, I'd put a marble slab along it, and have the greatest prep station ever, for rolling out dough, and such. tahir

there might be an issue with the gabions in that they are flexible and settle over time/creep a bit if loaded from one side.depending on the size ,angle and make up of the slope this creep is a variable.
i might be inclined to dig a trench and part bury the outside line of gabions to reduce side slip and use a rammer to stuff them tight before laying a floor and adding heavy things on top.some rebar driven into the subsoil so as the ends poke up with the empty gabions put on top will help to reduce side creep.rebar into the gabion fill with mesh on top would be good for the floor slab stability as well
wet clay is remarkably fluid and there will be a lot of weight on top as well as the sideways force so letting things settle between the gabion stage and building the patio/ovens over a winter might be a good idea.

ps running the digger (or even a big vibrating roller) over the cleared area a few times will help to compact the subsoil

i know that seems a lot of faff but i have seen quite a few unstable so called stabilised slopes,especially clay ones and overdoing it a bit to start is far better than trying to mend a wonky one.the moderate extra cost at the build stage should prevent any very expensive long term problems.

We'll be putting in a solid base, probably 600mm type1 wacked down properly. Good advice about rebar through
tahir

If I had a long run of gabions, I'd put a marble slab along it, and have the greatest prep station ever, for rolling out dough, and such.

We're going to do a concrete worktop over the gabions
dpack

If I had a long run of gabions, I'd put a marble slab along it, and have the greatest prep station ever, for rolling out dough, and such.

that would look a lot nicer than a steel one ,my ex washstand fire slab tooping in black and white marble looks nice and seems quite robust to thermal expansion etc. it was layed direct onto the wet slab the forms the bulk of the base.

any concrete or mortar that will be subject to thermal effects should be able to expand/contract freely and is best made with a mix of 1 1 4 ,cement,lime and aggregates or sand.this gives a very strong and slightly flexible product that is less prone to cracking than a pure cement or lime mix.

mass concrete use gravel and sharp sand.

renders use small pea gravel/grit and/or sharp sand depending on the depth/finish required (granite 1/4 inch to dust is a rather nice aggregate but less eco friendly than local gravels/sand)

mortar use soft sand
dpack

If I had a long run of gabions, I'd put a marble slab along it, and have the greatest prep station ever, for rolling out dough, and such.

We're going to do a concrete worktop over the gabions

that would look nice with crushed granite aggregate and snowchem (white cement) and lime.
with lime takes a while to reach full strength but is very solid after a few months but the cement will make it usable quite quickly.

remember to float it and trowel polish it before it sets for a smooth surface that will wipe clean easily.the float once set(but not hard)gives a much rougher result.
       Downsizer Forum Index -> Make Your Own/DIY
Page 1 of 1
Home Home Home Home Home