To do this I figured I could simply drill an 8mm hole through the base and pass a small endoscope camera down in the hope that I would be able to obse rve each layer in passing - a small scale subterranean geological dig.
Does anyone see any issue with this approach? Do you think I would see each layer as envisaged? I am particularly mindful of the consequences of punct uring any damp proof membrane that might be present, what to fill the hole with afterwards sufficient to restore whatever properties its former materi als provided etc.
Any advice gratefully received!