The completion of the pizza oven dome has been a long time coming, but it has finally arrived! Rows 7 through 12 are complete and the keystone is now locking the whole dome in place. These rows were definitely more difficult than the bottom rows due to gravity and the “inverted V”, but nothing that a little bit of patience and more time with the angle grinder couldn’t fix.
After I got up to row 7, the bricks are getting much more vertical. When a brick is sitting more vertical, gravity wants to pull it right down. This situation is where the indispensable tool is…indispensable. Using the indispensable tool, I was able to hold each brick in place until the mortar set up just enough to hold the brick on its own. As soon as the mortar could hold the bricks without using the tool, I moved on to the next brick. Patience was definitely tested here! For this reason, the top rows took longer than the bottom rows despite the fact that they had fewer bricks.
Another problem when you start to get up higher in the dome is the “inverted V” phenomenon. In the picture below, you can see where the bricks start to show the upside down V in the mortar. The further up the dome you go, the worse the V gets.
I suppose I could just leave the inverted V’s in place. But if I’m going to build this dome, why not put a little extra time to make it better? So I decided to get rid of these inverted V’s. It was time to bring out the angle grinder…again. To get rid of the inverted V, each brick has to be cut so that they fit together more tightly up the upper rows of the dome. Below are the bricks for my 8th row of the dome. After they are cut, the inverted V disappears.
This is really the process for each of the rows on up to the keystone. Eventually, the gap closes and the angles get pretty tricky. But at last, I made it to the keystone!
Unfortunately, a series of unfortunate events has occured. See, when I made it to the keystone, I was super excited and took lots of pictures. Then I kept building and didn’t take the time to write up this blog post until later. Over that time, I have lost my memory card with all of the final dome pictures! It was a sad day when I couldn’t find that card. It’s kind of like missing the climax to a movie!
Anyway, here is the only picture that I have before moving on. It still shows the final dome with they keystone in place, but lacks detail. I was able to stand, full body weight, on the top of the dome and it didn’t show any signs of giving way.
The one thing you’ll notice on the above picture is the landing (the front arch). I built the arch very similarly to how I built the entry arch into the pizza oven dome. There was one major difference though. In this arch, the smoke will be exiting through the top into the chimney. Therefore, I had to leave a hole at the top of the arch. How did I manage that? The first 6 bricks on each side were whole bricks. After that, I used bricks that were cut in half. This leaves a hole 1/2 brick wide for the smoke to escape.
There was one problem (and it turned out to be a major one) with the design of this arch. With an arch, all of the weight supported by the arch is transferred down and out towards the bottom of the arch. If the bottom of the arch isn’t supported (called buttressing), the arch will collapse. As you can see, I didn’t support the bottom of my arch. When I put the chimney on top, the bottom of the arch started to ease ever so slightly outward. You can already see small signs of this problem in the above picture. The keystone brick on the arch has creeped down slightly. I knew that once I started to put even more weight on the arch, the results wouldn’t be pretty.
Due to my lack of buttressing, I had to tear down and rebuild my arch. I’ll show you the final solution along with the chimney transition in my next post.
Despite my little hiccup with the arch, this was a major feeling of relief! The dome is complete! And it is rock solid.