Start With an Honest Assessment

Original boards are one of the quiet joys of an older home. They carry the marks of a century of feet, they warm a room in a way that laminate never quite manages, and they are very often still sound beneath decades of paint and carpet. But before you hire a sander or order tins of finish, spend an hour or two on your hands and knees. What you find will decide whether you are restoring, repairing, or replacing.

Begin by lifting a board near a corner or beneath a radiator, where access is easiest. You want to see what you are dealing with underneath as much as on top. Check the thickness of the boards, the condition of the joists, and whether any pipework or wiring runs through the gaps. Then look for the following:

• Cupping or crowning: edges curled up or centres raised, usually a sign of past damp or an uneven subfloor.
• Splits and shakes: long cracks along the grain, often caused by central heating drying old timber.
• Woodworm: small flight holes are common and often historic, but fresh dust beneath them means active infestation.
• Rot: soft, dark or crumbly timber, particularly near chimneys, external walls and bathrooms.
• Paint, varnish and stains: old paint is removable, but deep water staining may mean the board is better replaced.

If the boards are mostly flat, dry, and at least 18mm thick, restoration is realistic. If several are rotten or you can push a screwdriver into a joist, stop and deal with the structure first.

Sanding: Slow and Steady Beats Fast and Furious

A drum sander from a local hire shop is the standard tool, but it is unforgiving. Held still for a second too long, it will gouge a hollow you cannot sand out. Keep the machine moving at a steady walking pace, always with the grain, and never start or stop with the drum in contact with the floor.

Work through the grits rather than trying to remove everything at once. Start with an 80-grit belt to strip old finish and lift surface dirt, then move to 120, and finish with 150. Going finer than that can polish the surface and prevent a finish from soaking in. Use an edge sander for the perimeter and a scraper or detail sander for corners and under radiators. Punch any proud nail heads below the surface before you begin, and replace them with screws if the boards are loose and squeaking.

Filling the Gaps — But Not All of Them

Gaps are part of the character of an old floor, and filling every one of them is a mistake. Boards move with the seasons, and a rigid filler will crack, crumble and work its way out within a year or two.

For gaps under about 3mm, leave them alone. For wider gaps that let in draughts and collect crumbs, consider these approaches:

• Timber slivers: tapered offcuts of matching pine glued and gently tapped into the gap, then planed flush. The most traditional and longest-lasting method.
• Rope or cork strips: pushed into the gap and stained to match. Cheap, flexible and easy to reverse.
• Flexible acrylic filler: applied in thin layers and allowed to cure. It will move with the boards, though it can look flat compared with timber.

Draughts are usually better solved from below, by insulating between the joists. It is messier, but it works far better than filling every gap on the surface.

Choosing a Finish That Suits the Room

The finish determines how the floor looks, wears and is maintained, so choose with the room in mind rather than the tin with the nicest label.

• Hardwax oil: soaks into the timber, leaves a natural matte look, and can be spot-repaired without sanding the whole floor. Ideal for living rooms and bedrooms.
• Lacquer or polyurethane varnish: forms a tough surface film. Hard-wearing and easy to clean, making it a sensible choice for hallways and kitchens, though it can scratch and is harder to patch invisibly.
• Traditional wax: beautiful depth of colour and a soft sheen, but it needs regular re-waxing and will mark if water is left standing.

Always test a small area first. Old pine darkens dramatically with age, and an amber-toned oil will look quite different on a pale patch than on the rest of the floor.

Repair or Replace: Knowing When to Stop

Not every board is worth saving, and pretending otherwise leads to a floor that looks patched and uneven. Replace boards that are rotten, badly split, or so thin they flex underfoot. The trick is to match them properly: source reclaimed boards of a similar width and thickness, let them acclimatise indoors for a week or two, and fit them the same way as the originals, whether that means tongue and groove or simple square-edged boards laid over joists.

Cut out the damaged section cleanly with a fine saw, keeping the cut over a joist where possible so the new board has something solid to fix to. A careful patch, finished to match, will disappear once the floor is sanded and oiled.

Living With Restored Boards

Restored boards are not fragile, but they do reward a little attention. Fit felt pads to furniture legs, avoid wet mopping, and keep the room at a reasonably stable temperature and humidity — sudden blasts of dry heat are what cause new gaps and splits. Sweep or vacuum regularly, as grit is the main cause of dulling. Re-oil high-traffic areas every year or two and the floor will quietly improve with age, carrying its next century of footsteps as gracefully as its last.