You mean laying new engineering floor on top of it directly?It looks like an ashfelt floor to me, but not easy to tell as I can't see the whole area. I would leave it alone unless absolutely necessary.
You mean laying new engineering floor on top of it directly?It looks like an ashfelt floor to me, but not easy to tell as I can't see the whole area. I would leave it alone unless absolutely necessary.
I had wondered about ash or slag. We certainly have a few houses around here where the floors are compacted colliery slag mixed with some clay (also a by product) as a binder, presumably. After 100 years they are rock hard, albeit a bit brittle, and there was a tendency round here the1950s to cover them with asphalt. All the ones I've seen were pre-War thoughFor example: power station ash, coal slag from pit heaps, mud and cement in the SW - and even some terraced houses where I noticed Tarmac had been stomped down.