At least two weeks before you plan to sand a restore an old floor, Bath floor sanding would ask for the carpets to be lifted.
For two reasons:
1/ This enables the boards to breath again after being covered by carpet and underlay. They will often have a disproportionately high moisture content.
This gives the chosen gap filling method the best chance of working as the gaps in floorboards will increase as the boards dry and the filler will fall out.
One of the problems when or rather opportunity to solve something is moisture.
Often in old Victorian houses the air bricks have been blocked up and the void under the house gets damper and damper.
As a floor sander in Bath we often come across this issue.
It is often compounded by the floor boards being overlaid with carpet and underlay. That really stifles the draft !