It has been a long time coming, but the time to build our pizza oven on our patio has finally arrived. Similar to so many other DIY projects, the beginning is definitely not the most glamorous part. Instead, it is simply the foundation of the rest of the project. Without a good foundation, the pizza oven couldn’t exist.
So I actually misled you (a little) in the beginning. We aren’t actually breaking ground on our pizza oven foundation right now. Remember last year when we built our patio? We built the foundation to our pizza oven at the same time. We had lots of extra help from some workers (Dad, friends, etc.) so it was a perfect time to put them to good use. We pay friends with food and beer, we get manual labor in exchange. Good deal for us? I think so!
Choosing the Size of the Foundation
The pizza oven that we are building is going to be a dome style Italian pizza oven that has internal diameter of 36″. This is important because all components from foundation up needs to be the right size for the 36″ oven.
Based on the plans from both The Bread Builder’s book and the Forno Bravo plans, the size of this foundation needs to be about 70″ wide by 80″ deep. This leaves some extra room on the outside of the block stand for finish materials. Here is how it breaks down: 36″ internal oven diameter + 9″ oven firebrick + 12″ insulation = 57″. That leaves about 6 inches on each side to put on finish materials.
Materials & Cost
Here is everything that we used to build the foundation:
- 80lb bags of Quickrete: 35 @ $3.60/bag = $126
- 1/2″ rebar, 10′ ft sections: 4 @ $5.20/pc = $21
- Stone base: We bought a whole truckload (18 tons) for the patio, but this was probably 1 ton: ~$30
- 8ft sections of 2×6 lumber for forms: 4 @ 5.70 = $23
- Wire remesh: This depends on how you find it. Sometimes it comes in a big roll. Other times you can find smaller sections. ~$10
- Some spare bricks or pieces of concrete: FREE
Total cost for the pizza oven foundation: $210
Here are the tools that I used (of course, if you don’t have them there are always ways to improvise):
- Tamper for the stone base
- Wheelbarrow to mix concrete
- Shovel or hoe to mix concrete and shovel all of the gravel
- Sledge hammer or regular hammer to pound the stakes for the form
Breaking Ground on the Foundation
The foundation supports the entire pizza oven. Therefore, it needs to be both stable and strong. To make it stable, we built a base of compacted crushed stone about 12 in thick. Yes, this was overkill (normally 3″ is enough), but we had to make it level with the patio. Since our yard slopes slightly, one side of our patio needed a lot of stone underneath. The purpose of the gravel is to prevent freeze/thaw from damaging the slab.
On top of the compacted stone, we poured a concrete slab 5.5″ thick. This was pretty easily accomplished by building the form with 2×6 lumber. The slab was 70″ wide by 80″ deep. To save you from trying to do the math, this took about 35 of 80lb bags of concrete. Thankfully, Mr. Doug was there to lend a hand with the mixing, pouring, and screeding.
Rebar and wire mesh is an important part of the foundation to provide additional strength. Two pieces of rebar were placed along the outside of all four edges. One is 4″ from the outside edges and the other 8″ in from the edges. A sheet of wire mesh was placed on top of the rebar across the whole pad. Little pieces of brick held the mesh and rebar halfway up the slab at about 2.5 inches high.
Now it’s ready to finish mixing and pouring in the concrete. The good thing about the foundation is that it will never be seen. Therefore, you don’t have to make it nice and pretty. It’s a good thing, because mine was pretty darn ugly! But, it will do it’s job. At this point, that’s all that matters. I’ll worry about cosmetics later.
Next up is building the stand for the pizza oven.