The following images show the finishing touches to make the oven look nice. First I rendered the outside in a “Rustic” way, this means I cant render very well 
I used 5 parts sharp sand + i part cement.
Here you can see my “Rustic Effect”
My son just needs to finish the job he started of painting the oven!
Location of oven – To the left is last years project to build the Gazebo and BBQ, or bus shelter as it has been called.
Bit messy but here is the BBQ I also built.
The big concrete bulk now needs to be covered in a 4-8 inch layer of softcrete which will insulate the oven. The pictures below show me doing this.
These pictues show the wire frame I covered the oven with. These will help the soft crete to bond with the oven and provide some strength.
All the way around the oven
This is what you need to buy in the UK, its called Micafill, costs around £7 per 100ltr bag from building centres. I needed 6 bags total for this project.
The pictures below show the pouring of the soft crete around the wire frame.
The top is starting to take shape
Notice I have put a lot of insulation on the top, as heat rises this area needs the most insulation, I have around 8 inches.
Here is the rear view showing the finished insulation, now waiting to be rendered.
And the view from the side.
Ok so when I first made a decent size fire, I was initially concerned to see a hire line crack appear in 3 areas of the concrete roof. But these are perfectly natural, when concrete heats it naturally expands, once the cracks are formed my oven expands and contracts in the same way each time I use it. Once the oven is covered in insulating concrete this small hire line crack will not even be seen.
From the research I have done, you have a problem if smoke comes from any of your cracks, or if the cracks weaken the structure of the oven in any way.
In general the comments seem to indicate that all wood fired ovens have cracks and this is perfectly normal.
After spending most of the summer building my oven, I was a bit disappointed to find that after my initial small curing fires, my first attempt to cook pizza failed.
I checked my measurements and all seemed OK, my door was 62% of the height of the cooking chamber, and the fire seemed to burn well.
I decided to make the cooking chamber a bit smaller than the 3foot x 3foot initial design, I lined the inside with a layer of bricks, I also put another layer on the floor.
I also though that the fire I built may not have been hot enough, and that my door opening could be too wide.
I addressed all of these issues in one go, to see if the oven would get hot enough, so I raised the floor, which made the door height smaller than the recommended 62%, I also made the opening narrower.
I also got hold of some decent size logs to burn in the oven.
The fire was a little more difficult to get going as the smoke filled more of the chamber which chocked the flames, however once it was going all was fine.
The walls are now around 1 foot wide, and the floor 1 foot deep, the oven takes 3 hours to get up to temperature.
Once the flames died down and I pushed a nice big pile of embers to either side to expose a nice big cooking area I placed the 1st pizza in and it cooked in around 3 minutes! Success !
I cooked just 4 pizza’s this time and they all cooked OK, I put my thick wooded door on to cook the last 2.
When I went to the oven in the morning to clean it out, around 12 hours later, the oven was still warm on the inside. Not warm enough to cook, but defiantly warmer than the outside. I was quite pleased with this as I have not insulated the oven yet.
So far this is what I know about the ovens performance.
Heat up time 3 hours – After 3 hours of good size fire I could not keep my hands on top of exposed concrete for longer than 10 seconds or so.
Time to cook pizza – 2-3 minutes.
Heat storing properties – As the walls, floor and roof are very thick, the oven is still warm after 12 hours, this is without insulation.
The pictures show the process to build the chimney and front arch.
Chimney starting to take shape with front arch.
Chimney from rear
Starting to look like a pizza oven now
Cleaning Brick work
1st small drying fire
The pictures below show the finshed barrel roof with the concrete side walls, also the concrete layer poured over the top of the brick dome.
Concrete Side walls
Brick oven roof complete, and starting to dry out.
The wooden former to hold the concrete.
Foil and Steel rods in place to give th eroof extra strength.
Concrete poured, and made into shape with float
After 1 day I removed the wood to reveal the finshed concrete roof.
The pictures show how the top arch is created, also concrete cladding to assist heat storage.
all four sides of the oven are now in place.
1st Arch of oven roof
So now we need to add extra heat absorbing material to the concrete floor, fire bricks are recommended but due to cost I decided to use clay bricks and terracotta tiles. The bricks are filled with a fireclay mix.
Oven floor ready to start, notice the cut out at the front, this is important as it provides an airflow over the front and up the chimney.
I used some spare cut bricks to build up over inside of the arch, I used bricks with holes in them so that air can get to the front of the oven.
Clay bricks
Look it must be strong if I can stand on it!
Its even level!
Now fill up with fireclay/sand/concrete mix
Done
I then layed my tiles on to this mix.
The whol oven floor is around 7 inch’s deep, which provides a large heat retaining mass for cooking in the oven for a long time after the fire is out.
Tech Details
Cheap Clay bricks 10p each!
Cheap Tiles
Fireclay/Sand/High Alumina content cement.
Effort
This part took around two hours.
I decided mainly due to cost to make the walls out of refractory concrete mix, so I made some wooden formers (Molds) to pour the concrete in. I made two formers, one for front and back and one for the sides. After the first side which was cast in one length I decided to split into two as it was quite heavy to lift. The front and back are the same except that the front has extra wood to make the hole where pizza’s needs to go!
Reinforcing steel mesh for the walls (Rebar)
Front ready to pour
Poured
This mix of concrete took lots of experimentation to get right, the down side of this heat resistant concrete mix is that it starts to harden straight away. It is solid within an hour, so you need to work very quick with it, I recommend you have some help. so that one person can mix, while the other tampers doen the mix into the former.
Trying out for size!
Tech Details
Wooded formers, made from 2×2
Refractory concrete, with high alumina content to resist heat. Exact details available on my DVD.
After the insulating soft concrete has set and you have removed the wood former, it is time to pour the strucual concrete with steel mesh that will support and provide heat storage for the oven floor.
Finished Softcrete, ready to start next phase
Start to pour
I am using the bricks as part of the mold for the concrete, I decided to not leave any expansion room for the floor. You could add a bit of wood all the way around then remove when done, this will allow for the wood fired oven floor to expand a little.
Half filled I now place steel mesh to reinforce the concrete
Almost done
Once done the supporting structure of the floor is 5 inch’s deep, which provides lots of strength and a large capacity to store heat.
All poured now just wait a couple of days for concrete to set.
Once set remove the supports and wood from underneath.
Rech Details
This is normal concrete mix 5:1:1 (Ballast, Portland Cement and Lime)
Effort – It took one person 2 hours to mix and pour this concrete.