I poured the hearth slab last weekend, but was too worn out after doing it to post on the blog... I took the forms off today and was pretty pleased with it.
Amazingly, it's exactly level. That or I need a new spirit level. The plastic 'skirt' method I used to hold the timber ring in place has made a strange sort of edge to the hearth slab, but it worked!It's done a good job of holding all the concrete in, and everything is well bonded together on very uneven walls. This gives me a nice flat, level slab to start building the oven on, a bit like a blank page. The little hole near the front of the slab is where the thermocouple wires come up from the front panel - there'll be six thermocouples by the time I'm finished.