Hardwood Floor Sanding Grit Sequence: A Practical Guide
The standard sequence for refinishing a hardwood floor is 36, 60, 80, then 100 or 120 grit. The rule that matters most: never skip more than one grit. Each pass exists to remove the scratches left by the previous one, and jumping from 36 straight to 80 leaves deep scratches that stay invisible until finish goes on and makes every one of them obvious.
Almost every bad-looking refinishing job traces back to the grit sequence. Not to the finish, not to the applicator, not to humidity. To someone deciding that the floor looked smooth enough after 60 grit and moving on.
Sanding is a subtractive process where each step has exactly one job: erase the scratch pattern from the step before it. Get that sequence wrong and no finish will hide it.
Choosing Your Starting Grit
Start too coarse and you remove wood you did not need to remove, and a floor only has so many refinishes in it. Start too fine and you will not cut through the old finish, which loads up your paper and wastes money.
| Floor condition | Start at |
|---|---|
| Heavy finish buildup, paint, deep damage, cupping | 24 to 36 grit |
| Typical refinish, old poly, moderate wear | 36 to 40 grit |
| Light wear, thin finish, previously well maintained | 50 to 60 grit |
| New unfinished flooring, already flat | 60 to 80 grit |
When you are unsure, test a small area in a closet or under where a rug will sit. Run one pass at your intended grit and see whether it cuts to clean wood. Adjust from there.
The Standard Sequences
Typical refinish: 36, then 60, then 80, then 100.
Rough floor: 24, then 36, then 60, then 80, then 100.
Light wear: 60, then 80, then 100.
Where to stop depends on what goes on next. For a waterborne finish with no stain, 100 or 120 grit is right. For an oil-based penetrating stain like DuraSeal QuickCoat, stop at 100. Sanding finer than that closes the wood grain and the stain cannot penetrate, which produces a blotchy, washed-out color.
The One Grit Rule
You can skip one grit in a sequence. You cannot skip two.
Going 36 to 60 to 80 to 100 is textbook. Going 36 to 80 skips two steps, and 80 grit paper does not have the cutting depth to remove 36 grit scratches. Those scratches are still there. You will not see them on bare wood in daylight. You will see all of them the moment finish goes down, because finish fills scratches and reflects light off them.
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Edges and Corners
The drum sander cannot reach within a few inches of the wall, so an edger handles the perimeter. The edger must follow the same grit sequence as the drum, step for step.
Here is the mistake almost everyone makes: the edger is a disc sander, so it cuts in circles while the drum cuts in straight lines with the grain. If you match grits exactly, the circular edger scratches are more visible than the straight drum scratches next to them, and you get a visible halo around the room after finishing.
The fix is to take the edger one grit finer than the drum on the final pass, then blend the transition zone by hand or with a buffer. On a floor finishing at 100 with the drum, run the edger to 120.
Screening Before Finish
After the final drum and edger passes, a buffer with a 120 grit screen blends everything together and removes any remaining transition lines between the drum area and the edge work. Skipping this step is the reason so many DIY floors have a visible ring around the perimeter.
Vacuum thoroughly, then tack with a slightly damp cloth or a microfiber tack pad. Any grit left on the floor becomes a permanent bump under the finish.
Practical Points on Abrasives
- Buy more paper than the chart says. Coverage estimates assume clean wood. Old finish and residual wax load paper up fast, and worn paper burnishes rather than cuts.
- Change paper when the cut slows, not when it looks used. If you are pushing harder to get the same result, the paper is done.
- Keep the drum moving. A stationary drum sander gouges a floor in under a second. Start moving before lowering the drum and keep walking through the pass.
- Always sand with the grain on the final passes. Cross-grain sanding is acceptable on the first coarse pass for a badly cupped floor, but it must be fully removed by the next grit.
Checking Your Work
Before the finish goes on, kill the overhead lights and put a work light on the floor at a low angle, nearly parallel to the surface. Raking light reveals every scratch, swirl and drum mark that overhead lighting hides completely.
What you see under that light is exactly what the finish will amplify. If you find deep scratches at this stage, go back a grit. It is a bad hour of work. Discovering the same scratches after three coats of finish is a bad week.
Frequently Asked Questions
Straight answers for Cape Cod contractors and property owners.
What is the correct grit sequence for sanding hardwood floors?
The standard sequence for a typical refinish is 36, then 60, then 80, then 100 grit. For a rough floor with heavy buildup or damage, start at 24 and run 24, 36, 60, 80, 100. For a lightly worn floor, 60, 80, 100 is enough. The critical rule is never skipping more than one grit, because each pass exists specifically to remove the scratch pattern left by the one before it.
Can I skip grits when sanding a floor?
You can skip one grit but never two. Going from 36 to 60 to 80 to 100 is textbook. Going from 36 straight to 80 skips two steps, and 80 grit paper does not have the cutting depth to remove 36 grit scratches. Those scratches remain in the wood and are nearly invisible on bare floor, but they show clearly once finish goes down, because finish fills scratches and reflects light off them.
What grit should I stop at before staining?
Stop at 100 grit before applying an oil-based penetrating stain like DuraSeal QuickCoat. Sanding finer than 100 closes the wood grain and prevents the stain from penetrating properly, which produces blotchy, washed-out color. For a waterborne finish with no stain, you can go to 100 or 120 grit. Going beyond 120 on any floor that will be stained is a common and costly mistake.
Why do I see circular marks around the edges of my floor?
That halo is caused by matching the edger grit to the drum grit. An edger is a disc sander that cuts in circles, while the drum cuts in straight lines with the grain. Circular scratches are more visible than straight ones, so identical grits leave a visible ring. The fix is running the edger one grit finer than the drum on the final pass, then blending the transition with a buffer and a 120 grit screen.
How much sandpaper do I need for a floor sanding job?
Buy at least 50 percent more than the coverage chart suggests. Coverage estimates assume clean wood, but old finish, residual wax and adhesive load abrasive up quickly. Change paper when the cut slows rather than when it looks worn, because worn paper burnishes the wood instead of cutting it, which leaves a polished surface that will not take stain evenly. JR Hardwood Supplies in Falmouth stocks the full grit range.