DIY vs Pro
Sanding and Refinishing Hardwood Floors: The Process
August 12, 2026 8 min read By Fort Worth Flooring Co
Refinishing looks simple from outside: sand the old finish off, put a new one on. The reason two quotes for the same floor differ by 40 percent is entirely in the detail of how each of those steps is done.
Before anything: the assessment
Board thickness. How much timber sits above the tongue, because that is all a sander can remove. A floor that has been sanded twice already may not have a third pass in it. This gets measured, not estimated.
Moisture. In the boards, and in whatever is beneath them. A floor over a damp crawl space or a slab passing vapour will move after it is finished no matter how well the coating goes on.
Fastener depth. Old floors sometimes have nails that have worked upward. Finding one with a drum sander damages the machine and the floor.
What the floor is. Red oak behaves differently from white oak, and both behave differently from original longleaf pine — which in the pre-war stock here is common, and which burnishes rather than cuts if worked at modern-floor speed.
Preparation
Furniture out, doors off, shoe moulding or quarter round removed carefully so it can go back. Vents lifted. Any protruding fastener set below the surface.
Repairs happen now, not later. Boards being replaced are cut out and woven in before sanding, so the new timber gets sanded flush with everything around it. A board fitted after the floor is finished will always read as a repair.
The sanding sequence
This is where quotes diverge.
A full refinish is a sequence of cuts, each one removing the scratch pattern the previous one left. A typical sequence runs from a coarse grit to cut through the old finish, through an intermediate, to a fine grit that leaves a surface ready for coating.
Skipping a grit saves an hour or two and leaves coarse scratches that were never fully cut out. On bare wood you will not see them. Under stain, and under raking afternoon light from a west-facing window, they read as parallel lines across the boards. The fix is starting over.
Edges and corners are cut with different machines from the field, and matching the cut between them is what separates a good floor from one with a visible halo around the perimeter. Closets and stair treads are hand work.
Dust containment happens at the machine, connected to a vacuum system that captures the dust at source. A sheet taped across a doorway does not do this. In an occupied house it is the single most noticeable difference between a careful crew and a fast one — and in a pre-1978 house, where old coatings are being disturbed, containment is a documented procedure rather than a courtesy.
Filling
Gaps and small defects get filled after sanding, and the season matters here more than people expect.
North Texas indoor humidity swings from around 20 to 30 percent in a heated January house to above 50 percent in July. Boards are at their most contracted in winter. Filler troweled into gaps at that moment gets squeezed out when the boards close up in summer.
If a floor is being refinished in January and the gaps are the reason, the honest advice is often to fill lightly or not at all and reassess in May.
Stain
Samples get raised on your actual floor, in your actual light. A colour chosen from a card in a showroom is a colour chosen under different light on different timber.
For red oak taking a dark colour, water-popping comes first: the sanded floor is wetted so the grain raises evenly across the whole area, and the stain then takes uniformly instead of blotching. It is an extra pass over the entire floor and it is not optional if you want the result you were shown.
Coating
Three coats is standard. Four goes on kitchens, entry halls and anything they open onto.
Between coats the surface is abraded so the next coat keys to it. Skipping that between-coat abrasion is another invisible shortcut that shows up as adhesion failure a few years later.
Waterborne two-component finishes return the room to light use sooner, hold their colour rather than ambering, and carry lower odour. They cost more per gallon and are worth it in a house nobody can move out of.
Oil-modified polyurethane is cheaper, builds well, and warms in colour over time — which suits old pine and does not suit white oak.
Getting the room back
Staged rather than given as one date. Light foot traffic comes first, then furniture, then rugs — rugs last, because a finish that has taken foot traffic has not necessarily reached full cure, and covering it early traps solvent.
Anyone who tells you the room is fully ready the day after the last coat is describing a different finish from the one they applied.