Introduction: Pizza, Wood Fired Oven Build
This build is actually composed of two elements, a Wood fired Oven and an outdoor kind of Garden/socialising space.
I had been considering building a Pizza oven for some time, particularly as the weather started to improve through spring. I spent hours going through online photos, videos and forums gleaning as much information as possible initially for ideas and inspiration until I had a rough design in mind.
I initially was going to go for a relatively cheap and simple design using exercise balls and vermiculite, I soon discovered from forums that although perfectly functionable they do not really have years of life in them. I amended my mental idea of how I wanted it to look and went a little more adventurous.
The most important thing for people is probably time and cost. Firstly I am not a professional builder/joiner more of a competent DIY'er. The CV19(1) lockdown had just started and I had time on my hands, a little savings and bit of garden that was going to waste.
I completed both builds in 3 weeks pretty much solid on my own. The weather was good and I would work from around 9am through to 7pm. In that time I was nipping out for timber and other supplies and waiting for mail order supplies so I would not consider my efforts shear hard labour. That said it was hot hard work and I did shed a couple of stone which is always good.
Cost wise I estimate that the building cost me somewhere in the region of £1000 and the Pizza oven around £800, I didn't anticipate the extra cost of some specialised materials needed for the oven.
I had about a third of the required red bricks and all of the roof tiles already.
Step 1: Starting the Outbuilding
I have had this piece of garden which was gradually gathering more and more bits and pieces of stuff and was turning into a bit of an eyesore. So there was no objections from the long haired general on building something family friendly on the space.
I didn't really put much thought into size aside from wanting it to be large enough to use as a kind of garage for my old land rover in the winter. Aside from that I googled outbuilding planning laws and just had to ensure it was 2 meters from any boundary to ensure I was not height limited.
I then simply pegged it out and started digging holes two foot deep for the posts making sure they where all square. I used x6 large treated 200x200mm gate posts for the main pillars as they where going to carry the substantial weight of traditional pantiles. The footings are rubble under concrete blocks and back filled with cement once the posts where in place.
Step 2: Wall Plates
From this point on I used almost exclusively 2x4 timber.
I neglected to cut in the notch for the wall plates before erecting the posts which made it quite laborious to cut them later with a chainsaw and a chisel.
I had to use two lengths of 2x4 joined together in each quarter for extra strength, due to the size of the building I used 8 lengths in total for the wall plates.
Step 3: The Roof
Again using 2x4 I made simple roof trusses all identical and with help from the father in law set them and secured them to the wall plates. I cut bird mouths into the trusses where they met the wall plate.
Unfortunately in my rush I neglected to photograph the fitting of the battens, membrane and laying of the pantiles.
I made sure not to make this error when documenting the building of the oven.
I then filled in the rear of the building with Feather board and made doors (purely so that I could park my old Landrover in there in the winter), again out of feather board for the opposite end of the building from the oven.
I also used gate posts to make the knee braces for extra strength.
Step 4: The Wood Fired Oven Part 1
1. I started by laying out where I intended to place the oven and work surface, I knew that I wanted a round structure rather than a plain square base.
2. I used a wood to construct a simple frame for cement base. I was able to borrow a friends cement mixer, this saved a lot of time as opposed to mixing it in a wheel barrow.
3. I constructed the circle for the oven base from think cardboard and pegged its side to keep its form (The oil tank wasn't staying the there)
4. The post in the middle of the circle was to assist me laying the bricks. I used a piece of string to occasionally measure the circle.
Step 5: Laying Bricks
I used old solid clay bricks entirely for the entire build including the dome as it worked out considerably cheaper than buying firebricks. I was able to buy the extra I needed at 40p a brick from a farmer friend. I needed somewhere in the region of 500-600. I found the brick laying stage the most labour intensive stage of the build and my back agreed.
1. I laid the bricks in the pattern I required leaving a gap for the arches I would use to store wood under the worktop. I used left over concrete blocks to line the dome base for extra support in order to save on red bricks.
2. I made forms for the arches out of plywood and timber.
3. I used paving slabs with some slate tiles on top for the worktops.
Step 6: Dome Base
1. I filled the base with just about anything I had laying around, tyres rubble and soil and made sure it was well compressed.
2. Research had told me that the crucial thing from here on was insulation. The top of the base was then filled with glass bottles, I had read they are a reasonable insulator (not sure how true this is)
3. I then added a layer of vermiculite cement and on top of that and two layers of vermiculite boards. I bought 25 vermiculite bricks from ebay thinking they where fire bricks - they are not!
I then realised I would need to fork out for expensive fire bricks for the oven floor.
3. The firebricks where cut and laid in a herringbone style. This ensures pots and pizza paddles slide and don't catch on edges.
Step 7: Oven Opening Construction
To build the arch or oven opening I had to decide on how I would construct my dome. I researched the death out of dome construction and learned that traditionally in the very distant past the domes where formed from a pile of damp sand. I know that many people opt for using a wooden jig fixed to the centre of the oven floor and build a nice tidy brick dome. However as mine would be rendered and I wanted it complete in a day I went old school.
1. To build the the opening I built a wooden form in the shape and size I was aiming for, you need to do a few basic calculations at this stage as in order for the fire to draw correctly there is a ratio to entrance height and dome height2. I then laid bricks to the form.
2. Using timber I constructed a form and on top of that the brickwork and poured it with refractory cement (remember to leave a hole for the chimney). I attempted to build a brick arched roof but it was two difficult at such little pitch and I needed it to be strong enough to hold a heavy clay chimney pot. Normal concrete might of cracked with the heat.
Note: I had already purchased a cast iron door from Poland at this stage (£60) so I knew my doorway opening measurement.
Step 8: Dome Form
1. I made to cardboard semi circles and joined them together to form a cross, this was merely a guide to achieve my 1 meter wide 50cm high sand dome.
2. Using damp sand I built up the dome, this took a surprising amount of sand.
3. I then laid wet paper over the sand ready to start the brick dome.
Step 9: Dome Construction
It was now a simple case of using half bricks to build the dome, keeping tight to the sand form. I t crucial that you use some sort of refractory cement, I used a mixture known as homebrew that is referred to in many forums. made up of clay powder, cement sand and lime. (There is much debate on quantities, I can't quite remember my mixture ratio)
As I said before I tried to make the inside as tidy and cement free as possible (to avoid cement dropping in my pizza) but the outer cosmetics where not really an issue to me.
Once set I then employed my 7 year old to climb inside and clear out the sand, paper and carboard.
Step 10: Dome Insulation and Completion
1. I used insulating blanket (very pricey) held down by chicken wire as the first insulating layer and then added a layer of vermiculite cement, a layer of normal render and masonry paint.
2. The chimney was pinched from my father in laws garden where it had a plant pot in it.
3, Once complete we had a few small fires to cure the cement.
Step 11: All Finished
When I was constructing this I had a few comments from the In-laws about all the work it was taking to probably be used once.
Of the many additions to my property I can hand on heart say this has been the most rewarding and worth while, it has been used almost every weekend even now at the end of Autumn. It is an outstanding social space.
In between lockdowns my kids have had their friends round for pizza parties, we have had our friends round for little parties, been worth every bit of graft.
With a slight addition of an internal removable door (Vermiculite boards) we have became very proficient at using the heat that it is capable of storing. We will cook Pizza at around 500 degrees Celsius in the early evening, let it cool a little then cook steak and Veg etc. Before going to bed we put in the Sunday meal, we have slow cooked Lamb and Beef. It is quite usual to be well over 100 degrees Celsius the following lunch time.