The short version
- Sanding a typical job takes one to two days. The finish takes longer than the sanding, and it is the part that sets the schedule.
- Waterborne finishes can usually be recoated within a few hours. Oil modified polyurethane usually needs overnight between coats.
- Walkable, ready for furniture and cured are three different points. Manufacturers typically give about a week of cure for waterborne finishes and about a month for oil modified.
- Stain, repairs and humid weather each add time, and all three are known before the job starts.
- In the 635 places in our data at /data/, approximately 60.5 percent of housing predates 1978, where containment for the federal lead rule is part of day one.
The three milestones people confuse
A finished floor is walkable in socks first, ready for furniture some days later, and fully cured only after that, and each milestone depends on the product used.
A coat of finish dries when its carrier, water or solvent, has evaporated. At that point it is dry to the touch and can take a careful footstep. It is not yet hard. The film goes on hardening for days or weeks, which is what curing means.
During that time the floor is usable and vulnerable. A chair dragged across it can leave a mark that would not have happened a week later. A rug laid down too soon can trap what the finish is still releasing and leave a dull rectangle in the shape of the rug.
So we give three dates in writing before the job starts, for the specific product going down: when the floor takes socks, when furniture goes back, and when rugs can return. Plan around the third one, and the first two take care of themselves.
Walkable is not cured. Most damage to a newly finished floor happens in the gap between the two.
A typical job, day by day
For a few rooms of solid hardwood, expect a day of setup and sanding, a second day of sanding and first coat, and one to three more days of coats, depending on the finish and whether the floor is stained.
Day one is preparation and the first sanding passes. The rooms are already empty, the doorways are sealed, vents are covered and the machines are connected to extraction. The coarse pass removes the old finish and flattens the boards.
The second day completes the grit sequence, the edger work at the walls and the hand work in corners. If the floor is not being stained, a sealer or first coat can often go down that afternoon. If it is being stained, the stain goes on and has to dry fully before any finish covers it.
From there it is coats. Three coats of waterborne finish can sometimes be applied over a day and a half. Oil modified polyurethane is normally one coat a day. The figures in the table are typical ranges from finish manufacturers, and the label of the product used on your floor is what governs.
| Milestone | Waterborne finish | Oil modified polyurethane |
|---|---|---|
| Time between coats | About 2 to 4 hours | About 8 to 24 hours |
| Walk on it in socks | About 24 hours after the last coat | About 24 to 48 hours after the last coat |
| Furniture back, lifted and with felt pads | About 2 to 4 days | About 4 to 7 days |
| Rugs back, full cure | About 7 days | About 30 days |
| Smell while it cures | Mild, clears quickly | Stronger, lasts several days |
Why the finish sets the schedule
Each coat has to dry before the next one goes on, and a coat applied too soon traps solvent underneath it and stays soft.
It is tempting to ask for the coats to be applied faster. The time between coats is not a courtesy. A finish that is recoated before it has dried cannot release what is under the new layer, and the result is a film that stays soft, clouds, or peels.
Waterborne finishes dry quickly because water leaves quickly. They stay close to the natural color of the wood. Oil modified polyurethane dries by reacting with oxygen, which takes longer, and it adds an amber tone that deepens over the years.
The choice between them is mainly about color and about whether anything has to match an existing floor. Schedule is the tiebreaker. If the house has to be back in use quickly, waterborne is the practical answer, and on a light or natural floor it is usually the right one anyway.
What adds days
Stain, board repairs, humid weather and a large or divided floor plan each lengthen the job, and all of them can be identified at the estimate.
Stain adds at least a day. It is applied after sanding and before finish, and it has to be dry all the way through. Dark colors on dense wood take longer. A finish applied over stain that is still wet will not bond.
Repairs come before sanding. Replacing stained boards, fastening loose ones and weaving in new wood can be an hour or a day, depending on what the floor needs. We find that out when we look at it, and it is in the quote.
Weather is the variable nobody controls. Finish dries by evaporation, and in a humid Philadelphia summer with the windows shut, every coat takes longer. Running the air conditioning helps. In winter, dry heated air speeds drying, and the house should be kept at its normal living temperature throughout.
Setup in a house built before 1978
In pre-1978 housing the work area is contained and the machines are connected to a vacuum under the federal lead rule, and that setup is planned into the first morning.
Floor sanding reaches painted surfaces more often than people expect. The edger runs against baseboards, shoe molding and door casings. In housing built before 1978, paid work that disturbs those surfaces falls under 40 CFR Part 745, which sets how the area is contained and how dust is collected.
This is the normal condition of the work here. The dataset we publish at /data/ covers 635 towns and Philadelphia neighborhoods, and approximately 60.5 percent of its 3,899,409 housing units predate 1978. In Philadelphia the figure is approximately 82.8 percent.
The containment does not add days. It adds an hour or two at the start and a specific cleanup at the end, and it is the reason to ask any contractor how the dust will be handled before agreeing to a date.
Where you live while the floor is closed
Plan to be out of the rooms being finished from the first sanding pass until the floor is walkable, and decide in advance how you will reach the kitchen, the bathroom and the bedrooms.
In a house with one floor of hardwood and an untouched basement or second floor, most families stay. The work area is sealed, and they live in the rest of the house. The hard cases are a first floor that includes the only route to the stairs, and a second floor hall that every bedroom opens onto.
There are ways around both. Coating can be timed for the end of the day so the floor dries overnight. A hall can be done in two halves. Some families take the job as the reason for a few nights away, which is the simplest schedule of all.
Pets and children stay out until the floor is walkable, and pets a little longer. A dog's claws on a finish that is one day old leave marks that a week old finish would shrug off.
Moving back in
Furniture goes back lifted, not dragged, with felt pads on every leg, and rugs wait for the full cure.
The first rule is that nothing slides. Furniture is carried and set down. Every leg gets a clean felt pad, including pieces that had them before, since old pads hold grit.
Rugs are the item people most want back and the one that has to wait longest. A rug with a rubber or latex backing is the worst case, because it seals the surface. Even a breathable rug should wait for the cure time on the product label.
For cleaning, use only a dry dust mop for the first couple of weeks. No damp mopping and no cleaning products until the finish has cured. After that, the routine is simple: remove grit often and use a cleaner made for finished wood floors.
How long a screen and recoat takes instead
A screen and recoat is usually done in a day, because nothing is sanded to bare wood and only one coat has to dry.
When the finish is dull or lightly scratched and the wood underneath is untouched, the floor does not need a full refinish. The surface is cleaned, abraded with a buffer so a new coat can grip, and coated once.
The rooms still have to be empty, and the cure schedule of the product still applies to furniture and rugs. But the days of sanding and the multiple coats are gone, and the floor keeps all the wood it had.
It only works on a sound finish. Where wear has reached bare or gray wood, or where a polish or wax has been used on the floor, a recoat is the wrong job, and we test for that before recommending one.
