Much better week this week, I managed to get lots of outstanding bits done. Early on, any gaps between bricks such as the chimney base were packed with castable along with any joints in the secondary arch. It was then time to get on with cementing the insulation blocks into place. These are ultra low density blocks which are able to take the heat from the fire brick wall as well as offer a good insulatory layer along the sides of the chamber. A bit fiddly on the wall side as it's quite narrow. Having completed that and the cement aloud to cure, the gap between the insulation blocks on the kiln and the yard wall was filled with concrete blocks and old bricks to butress that side of the kiln.
It was then time to build up the chimney, despite an aptitude for dropping my trowl down it, it went up reasonably quickly, managing to lay about 4 courses each hour which doesn't sound much but there was also a lot of brick moving and cutting of small 1inch bits as spacers, 2 or 3 per course. I still need to add a few more courses, it's standing at about 11.5 feet at the moment and I reckon it needs another foot.