Stage 5 - The Arch

This is where the rubber starts to hit the road! Today I decided to build the arch. I had bought some Perlite to pack between the bases of the oven walls and the outer walls and had cleaned enough bricks to build the three arches that would form the oven. The perlite will hopefully manage the thrust from the bases of the arch and may cushion the expansion of the oven when it is heated.

I went to the hardware/timber yard this morning looking for offcuts of plywood to make a form. They had given them all away the day before! Being nice people they gave me some offcuts of mdf. I set out the two clamped sides of the form using the trusty tape, square, a nail, string and a pencil. Having made the crucial measurements I traced a perfect semi-circle on the mdf and cut with a jigsaw. I had left one thing out and the consequences will become obivous as we go along.

Having set the form up I mixed mortar and started laying bricks. The process was quick and very satisfying until I got to the top of the arch. The bricks didn't meet and I had a gap that needed filling. Getting my friend the angle grinder out I started to cut a brick wedge. What a job! Dust everywhere. The first brick I chose was too hard, it took ages to work and broke when I started using a cold chisel on it. I eventually made two wedges that I set in as keys. Time will tell if they hold or not. At least the arch stayed up after I pulled the form out.

The second arch was easier and I was prepared for the final key wedge. The third arch was a dream!. I think the quality of the brickwork also improved as I gained experience and confidence. The pictures tell the story.