The story of our oven in Calgary AB

[Rinrat86]

A few years ago a friend told us, "you need to build a pizza oven". We laughed and had another beer, but apparently the idea didn't go away and DH and I have been researching pizza ovens off and on since then.
This spring DH grabbed the shovel and said, time to stop thinking and start doing. Oh oh, what have we gotten ourselves into?!?
I can happily say that we had a fun summer building a WFO, learning more that we could have imagined about concrete, fire brick, mortar and more; stopping and researching when we got into tough spots; forging ahead and hoping for the best at times. We started in May and completed the oven in September (and still had lots of summer adventures). On Halloween we hosted our first (and likely not last) open-hearth party where we had many neighbours drop in for pizza before heading out trick-or-treating or off to Halloween parties - over 45 pizzas served in 3 hours!

I tried to take photos throughout the build and will share now. (hopefully I can make this work!)

[Rinrat86]

Step one the foundation. We framed it up with 2x6s and lined it with steel mesh and rebar for strength. We stuck with Concrete Mix from HomeDepot (best pricing we found in the city) and for the base we simply mixed it in the wheelbarrow and dumped it in.

[Rinrat86]

Next step was framing the hearth. We put rebar in every second opening of the CMUs and stuffed the others with the empty concrete mix bags. We placed Hardibacker board (cement board) over the CMUs of the stand. The rebar was then bent over so it would be parallel to the bottom of the hearth and tied in with steel mesh. The hearth was then framed with 2x6. The resulting hearth is 61x78 and 5.5" thick.

[Rinrat86]

Something a little odd was that the halfblock CMUs we put in the centre are slightly taller than the full blocks that went around the outside of the stand. This resulted in a slight curve to the bottom of the hearth.

[Rinrat86]

For pouring the hearth we got a little smarter and rented a mixer. Even better we squeezed the truck through the back fence (whoever invented the side mirrors that fold in is a genius!) and backed it right up to the hearth. So instead of having to figure out how to lift concrete up to the hearth, I just needed to lift the bags of concrete up to the tailgate where DH could get them. Of course it started to rain just after we got started so we had to quickly rig up a tarp!

[Rinrat86]

One more photo of the just poured hearth. With this angle you can see how the framing for the hearth was supported. We used shims to ensure the framing was perfectly level.

[Rinrat86]

The time when the concrete was curing was very beneficial. It gave us time to make sure we were thinking of the same thing (ya, we really built the base without ensuring that we were both planning the same thing). We experimented with some design ideas for the entry arch, and it gave me time to source ceramic fibreboard, ceramic wool and heatstop mortar mix. We have no experience with concrete and mortar. Building the foundation and hearth were the first time we'd mixed concrete so we made the decision that we would not try to do any home brews. Thats why we chose to go with fibreboard and heatstop mortar mix (powder form).

We figured out the size of the entry arch and made a cardboard template for the floor. Next step involved picking through our pile of firebrick (bought used) to find the 'best' ones for the floor. I tried to lay it out so we ended up with as few cuts and small bricks as possible, but there were a few. My husband destroyed a brick or two before we figured out how to make the cuts. We have a 4.25" wet saw and an angle grinder. We found the wet saw worked really well even though it took two cuts to get through the bricks.

The brick floor sits on top of 2" ceramic fibre board. The only place we used mortar was to help hold in the small partial bricks.

[UtahBeehiver]

Admire you that you were able to do the build with a 4.25" wet saw. Just goes to show that builds are possible with smaller saws or in some cases a brick chisel and a hammer.

[Rinrat86]

And now the fun begins. We built ourselves and IT using a castor wheel, piece of 1x2 and an L bracket. For the first round of bricks on the dome the IT was simply duct taped to the floor. After we had the first circle in place we made an X with 1x2s to prevent it from shifting around within the circle. At this point I was waiting for DH to cut bricks in half for me, then I'd mortar them in. If he'd cut a pile for me I could place them during the week (when he had to got to that silly time killer called a job) He did a really good job of figuring out angles - the first ones being for the transition from the dome to the entry arch.

[Rinrat86]

Here you can see better how the IT was held in place. We had excess fibreboard so used that to provide the frame for our entry arch. I cut the board short so that it rested on top of 2x2s. When the arch was finished it was easy to remove the 2x2s, then pull out the form. I messed up with the mortar on the arch and it took 2 tries to get it right.

[Rinrat86]

Thanks UtahBeehiver. It was a bit of a challenge. We tried setting up a jig so we could cut one side, flip and cut the other, but our workbench is a folding craftsman portable workbench and we found it just didn`t give us consistency. We had much better luck with a tsquare ruler and a pencil. Marked both sides, cut once, flip, cut again, then split it with hammer and chisel. It worked quite well.

[Rinrat86]

I wish I could say, like so many others on the forum that we used this mathematical formula to figure out just exactly the right angle for our arch and for the arch-dome transition, but really we laid it out on the floor, got out a pencil and gave it a go. I think DH destroyed a couple of bricks getting it right but we did have extras :-)

[Rinrat86]

The arch was a challenge. There are so many different designs and plans. We ended up using semi arch just because we liked the look and size of it. Its about 18" wide and 13" high at its highest. The side is 3 full and one half brick high. The outer arch is about 1 inch wider than the dome's arch giving about a half inch lip on each side to rest our door against. There is no lip along the top of the arch, just the sides. I cannot recall if we mortared the entry arch to the dome ... I don't think so. We did not put in a break between the dome and the arch, primarily because neither myself or DH could get our heads around it. It just seemed beyond our capabilities so we skipped it.

[Rinrat86]

The arch - dome transition was certainly the hardest part. We looked at so many different posts here and on other sites on the web that I think we were going cross eyed. We did eventually get it worked out but I know I couldn't explain it to someone else. These photos show the first row of the transition.
By this point we were on the 8th row of bricks and I'm not sure if you can see or not, but we were doing some bevelling of the bricks. We also found that the slope had gotten to the point where it was so steep that we were only laying 3 bricks at a time and would use the IT to hold the one of them while the mortar set up. I found that it wasn't a big deal to come out, mix up a small bit of mortar, set a few then go off and do some other household task (like the laundry you can see in the background :-)

[Rinrat86]

Hmm it appears I missed out on details for the second row of bricks for the transition. I remember that something messed up and one or two of the bricks had to be remortared. I also crawled in there and put mortar in the crevice between the dome and arch to help support it and to smooth it out.
This is the next photo I have and appears to be from the first full row after the transition was complete. At this point the chimney bricks were just dry stacked.