So there I was a'diggin this 'ole.
Under instructions from "she who must be obeyed" was diggin a hole to transplant some obscurely named flowering shrub.
A foot or so down came across a partial Q-block ...solid..needed a sledge hammer and chisel thing to break up..been there for 7+ years.
Posted only because on another thread someone mentioned that Q-blocks will disintegrate with damp..myth explode methinks