How do I re-oil a wooden floor that has gone dull and patchy?

An oiled floor is maintained rather than refinished — but only if you catch it before the timber is exposed. How to tell which you have and what each needs.

Difficulty: intermediate
Time: 4 hr
Read: 5 min
Safety: caution

Short answer

If the floor is dull but the timber is not bare, clean it thoroughly and apply a maintenance oil — no sanding needed. If the finish has worn through to raw timber, or there are grey or black patches, that area needs sanding back before oiling, and a badly worn floor needs sanding as a whole.

The great advantage of an oiled floor over a lacquered one is that it is maintained in place, coat by coat, without ever being sanded. That only holds while there is still finish in the timber. Once traffic has worn through to bare wood, dirt and water get into the grain and the repair moves from a morning's work to a full sanding job, so the decision that matters is telling those two states apart.

Safety

Cloths, pads and buffing bonnets soaked in wood oil self-heat as they cure and have caused house fires. Lay them out flat and singly outdoors to dry, or seal them under water in a metal container, before disposal. Never leave them bundled up overnight.

What you'll need

The manufacturer's wood floor cleaner, or an appropriate intensive cleaner
Maintenance oil or refresher for the product on the floor
An applicator pad, and lint-free cloths
A buffing machine with white and red pads, hired for the day
A random orbital sander, for spot repairs

Step by step

Work out whether the finish is worn or gone.Put a few drops of water on a dull area. If it beads or sits, there is still finish and the floor needs cleaning and re-oiling. If it soaks straight in and darkens the timber, the finish has gone in that area and the wood is exposed. Test the traffic lanes, the doorways and under a rug, and compare.
Identify the existing finish before buying anything.Oil, hardwax oil and lacquer are maintained completely differently, and a maintenance oil over a lacquer will not adhere. If you do not know, test in a corner: an oiled floor absorbs a drop of oil, a lacquered one does not. Where possible, use the same brand's maintenance product.
Clean the floor properly — this is most of the job.Vacuum thoroughly including the edges, then wash with the manufacturer's cleaner or an intensive wood floor cleaner. Years of general household cleaner, polish and residue must come off, or the new oil sits on top of it. On a badly built-up floor this may take two passes with a buffing machine and a red pad.
Let it dry completely.Any moisture left in the timber or the grain stops the oil penetrating and can leave cloudy patches. Give it several hours to a day depending on how wet the cleaning was, and on the room.
Sand out any bare or damaged areas.Grey or black patches are water and dirt in exposed timber and will not be covered by oil. Sand those areas back to clean wood with the grain, feathering the edges, and blend the colour if the surrounding floor has darkened with age.
Apply the maintenance oil thinly and buff it back.Very thin — a maintenance coat covers a large area from a small quantity. Work it in with a pad or a buffing machine with a white pad, then remove all excess with clean cloths within the working time. Excess left on the floor stays tacky, cures patchily and picks up every footprint.
Keep off it until it has cured.Follow the tin: light foot traffic after a stated period, rugs and furniture much later. Putting a rug down on a floor that has not cured leaves a permanent outline.
Set up the maintenance so this does not recur.Door mats at every external door, felt pads under all furniture, no wet mopping, and the manufacturer's cleaner rather than a general household product. Then re-oil the traffic lanes before they go dull rather than after — a hallway may need it annually while a bedroom goes years.

Tips

Hiring a buffing machine for a day transforms both the cleaning and the oiling, and is the difference between a professional-looking floor and a patchy one.
Do the traffic lanes and doorways more often than the whole floor. Maintenance oil blends into an oiled floor without an edge, which is the whole point of the system.
Never use a steam mop or wet-mop an oiled floor. Water is what destroys them, and it gets in through exactly the worn areas you are trying to fix.

Common mistakes

Oiling over a dirty floor — The oil sits on top of cleaner residue and polish rather than penetrating the wood, and it stays tacky and patchy. The cleaning is most of the work.
Applying maintenance oil generously to make the floor look better faster — Excess oil cures on the surface rather than in the timber, staying sticky and showing every footprint. Thin, worked in, wiped back.
Using a maintenance oil on a lacquered floor — It cannot penetrate a sealed lacquer film, so it never dries and has to be cleaned off. Identify the finish first.

If it doesn't work

Floor still looks dull after oiling

Cause: Cleaner or polish residue preventing penetration — Fix: Strip the residue with an intensive cleaner and a buffing pad, let it dry fully, and re-oil.

Sticky patches days after oiling

Cause: Too much oil left on the surface — Fix: Wipe the area with the manufacturer's cleaner or white spirit to remove uncured oil, then buff a very thin coat in and wipe back thoroughly.

Grey or black areas that oil does not improve

Cause: Water and dirt in bare timber — Fix: Sand those areas back to clean wood, blend the colour, and re-oil the whole board or the whole area.

Keeping on top of it

Sweep or vacuum and clean with the manufacturer's wood floor cleaner (Weekly)
Re-oil traffic lanes, doorways and the kitchen area (Annually, or as they begin to dull)
Re-oil the whole floor (Every few years, depending on traffic)
Check and replace felt pads under furniture (Annually)

Questions people ask

How do I know if my floor is oiled or lacquered?

Put a drop of oil in an inconspicuous corner. An oiled floor absorbs it and darkens; a lacquered floor leaves it sitting on the surface. Water behaves similarly — it soaks into a worn oiled floor and beads on a lacquered one.

Do I need to sand before re-oiling?

No, if the finish is merely dull and there is still oil in the timber. Yes, locally, for any area worn through to bare wood, and as a whole floor only if it is worn through extensively.

How often should an oiled floor be re-oiled?

By area rather than by calendar. A hallway or kitchen may need traffic lanes doing annually while a bedroom goes several years. Re-oil when the surface starts to look dull and water stops beading.