This is what we started with. These are Victorian
oak blocks of good quality - just very grubby, layered with dirt
ingrained polish - usually referred to as 'patina' by antique dealers
- and all loose on their hotmelt bitumen bed.
The base beneath this block floor is a soft very friable lime and
sand screed. It had lost some of its integrity in places, reverting
to little more than loose sand. The damp proof membrane had been
provided by the hot-melt bitumen which was also the adhesive.
We picked up the floor two rows at a time, vacuumed out loose material
which we replaced with deeper hot-melt bitumen, then refitted the
blocks after cleaning each one back to bare wood.
Because the blocks had shrunk and moved around, our refitting closed
the gaps between them. As a result we had to make blocks from similar
old timber to compensate for the losses and that we could not re-use
the cut blocks at the borders.