Ever wanted a real wood fired pizza oven which will last for years and hold heat for roasting/baking? Well watch as I build an aerospace engineered DIY Pizza Oven which is robust, has high thermal capacity, efficient and doesn't use and balls, waste ply, sand piles and can be done by ANY novice. No Vermiculite. No Pearlite. No exotic thermal insulation.
I have never build a Wood Fired Oven before, I can't lay bricks and I have never rendered in my life. What I do understand is Engineering. So here I show how I did my Cheap Pizza Oven Build, the materials used which were mostly leftovers and by crude techniques. No bricklaying. No welding. Get ready to start scavenging and building!
A Few Facts:-
Vermiculite concrete is a great insulator but lousy at retaining heat - and only lasts a few years as it is relatively fragile. Pearlite is a little better but still with limited thermal mass.
Concrete does not burn and, if supported, will survive high temperatures - so no need for special materials. HOWEVER --- AND THIS IS IMPORTANT --- like all cast ovens like clay, concrete, cement based etc they all need to be cured before fired on full heat. This involves lighting a series of small fires, getting progressively larger and bigger over many days to progressively and gently cure the materials of the oven. Without this process the moisture in the concrete/clay etc will rapidly expand and can 'pop' to oven, either by cracking or shattering. I'm not concerned for this oven as the concrete is encapsulated by the metal drum and the insulation & render but it is an essential step if you are to avoid some catastrophic failure. At the end of the video you will see my first small fire. There are lots of KZfaq videos on how to do this.
Rockwool will survive a direct flame at 1000C and will not burn. I know - I tried setting fire to it myself with a flame torch.
Thermal mass means your oven stays hot once hot. Insulation then keeps it in!
A metal barrel as a former expands/contracts with heat (steel) the same as concrete.
So with all of this in mind, why not use a Metal Barrel as a former, leave it as part of the Metal Barrel Oven and make plain old concrete as the thermal mass - enriched with old tiles as ceramic tiles are fired at 1200C - twice as high as a wood fire burns which is about 650C, on the outside. Then insulate and finally render. No skilled brick laying, no fragile vermiculite concrete, great thermal mass properties.
This is a record of how I did it. I'm not a professional, don't take responsibility for how you choose to build things (health and safety) but the oven is great - watch out for cooking vids to come soon!
UPDATE - I have had some comments about costs. Yes it can be more if you buy everything new. It can cost less if you don't. I could do without the chimney (£24), hinges and brackets plus thermometer (about another £10+) so could have got a working oven for pennies. Likewise I could spend more on nice firebrick, fire insulation, cast iron door etc. So my aim is to show that some common, non specialised materials can be used cheaply and easily. Go scavenge and go build. Its not scary and can produce a great looking and really well functioning oven. The materials for the concrete and render cost £15 from B&Q.
UPDATE - I added tiles (as in the thumbnail) to make it look pretty for another £40 incl adhesive and grout after I made the video, so total cost is now £90. I can send more pics if you ask but will probably update in another vid. I see decoration as optional and include the stainless chimney in that which I could have done in mild steel for half the price.