It is early Spring (April) in the SE of England where I live. On a sunny afternoon, last week, I uncovered the oven for the first time this year to find some fairly nasty water damage. The video below shows the damage. I talk about “mysteriously disappearing” clay in the video. After a little more consideration it is clear that this is just water damage. Clearly water has been seeping through the covering and has eroded some of the outer clay content. The heavier sand particles are left on the oven surface hence the covering of sand on the dome.
I know have to patch cracks and fix the chimney. Hopefully she’ll be OK for another year once I get these repairs underway. We shall see!