“Refinishing” covers a range of jobs, from a light surface recoat to a full sand down to bare wood. Choosing the lightest option that solves the actual problem preserves more of the floor's usable wood over its lifetime.
Solid floors can typically be sanded several times over decades; engineered floors are limited by wear layer thickness. Know which you have before scheduling any sanding work.
Screening and recoating
Screening (light abrasion) followed by a fresh topcoat addresses dulling and light scuffing without removing significant wood. This works only if the existing finish is in reasonably sound condition and the wood underneath is not stained or deeply worn.
This is the fastest, least invasive option and is worth requesting by name — some contractors default to a full sand because it is a bigger job, not because it is necessary.
When a full sand is actually needed
Deep scratches through the finish into bare wood, cupping or unevenness between boards, or heavy staining usually require a full sand to level and reset the surface. This removes a measurable layer of wood, so it is not a step to repeat casually.
Ask your contractor how many sandings the floor has likely had (based on remaining wood thickness above the tongue) before agreeing to another full sand — very thin solid boards or shallow-wear-layer engineered floors have a hard limit.
Finish choice at refinishing time
Refinishing is a natural point to switch finish type — for example, from a worn polyurethane to a hardwax oil for easier future spot repair, or the reverse for higher wear resistance in a busy household.
Oil finishes generally allow small area touch-ups without re-sanding the whole room; polyurethane usually requires refinishing full boards or the whole floor to avoid visible lines. Factor this into which finish you choose, not just the initial look.
Between-refinish maintenance
Rugs in high-wear paths, felt pads under furniture, and prompt spill cleanup do more to delay the next refinish than any product marketed as a miracle floor treatment.
Avoid steam mops on wood floors — heat and moisture can damage both the finish and the wood beneath it, regardless of what the finish label claims about water resistance.