Quick Answer
For most hardwood floor refinishing projects, 36 grit is a common starting point, followed by progressively finer grits such as 50 or 60 grit and then 80 grit. Heavily damaged floors, thick paint, or multiple old finish layers may require a more aggressive starting grit such as 24 grit, while lightly worn floors may allow you to begin considerably finer. The important rule is not to jump directly from very coarse paper to very fine paper. Each sanding stage needs to remove the scratches created by the previous grit, otherwise those marks can remain visible after staining and finishing. The correct sequence therefore depends on the floor’s condition rather than one universal number.
Why Grit Choice Matters So Much
Sandpaper grit determines how aggressively the abrasive cuts into the timber.
Lower numbers represent larger abrasive particles that remove material quickly. Higher numbers contain finer particles that remove less timber and create a smoother scratch pattern.
This means using extremely coarse paper can quickly strip a damaged floor, but it also creates deep sanding scratches that must be removed later. Starting too fine creates the opposite problem: the abrasive may polish the surface without efficiently removing old finish, stains, scratches or uneven areas.
Norton recommends using the finest grit capable of producing the required result, because unnecessarily coarse abrasives remove additional wood and create more work during later sanding stages.
That principle is particularly important with older floors that may already have been sanded several times.
Every refinishing removes a small amount of timber. The objective should therefore be to restore the floor while preserving as much usable wood as possible.
A Typical Hardwood Floor Sanding Sequence
For a normally worn hardwood floor with an established finish, one commonly used professional sequence is:
36 grit → 50 or 60 grit → 80 grit
Norton currently identifies 36-50-80 as a standard floor-sanding sequence.
Other professional systems may use 36, 60, 80 and sometimes 100 depending on the floor, wood species and chosen finish.
These differences are not necessarily contradictions.
Floor sanding is not performed according to a rigid formula. A professional chooses the sequence according to how effectively each abrasive is cutting and what scratch pattern remains after each pass.
The objective is always the same: remove the damaged surface, eliminate scratches left by previous abrasives and create a uniform final surface ready for stain or finish.
When to Start With 24 Grit
Twenty-four grit is extremely aggressive.
It is generally reserved for floors with serious problems such as:
- Thick layers of old paint or finish
- Heavy adhesive residue
- Severe surface unevenness
- Deep scratches or damage
- Multiple coatings that finer paper cannot efficiently remove
Norton notes that painted wood floors may sometimes require abrasives as aggressive as 24 or even 16 grit.
That does not mean homeowners should automatically start there.
Using very coarse abrasive on a floor that only has light wear removes unnecessary timber and creates deep scratches that require additional sanding to eliminate.
A better approach is to test an area first.
Lägler recommends starting with the finest grit you think may work. If it is not aggressive enough, move coarser until the abrasive removes the finish efficiently.
This simple test can prevent significant unnecessary sanding.
Why 36 Grit Is Such a Common Starting Point
For many full refinishing projects, 36 grit offers a useful balance between cutting power and control.
It is aggressive enough to remove many old polyurethane, lacquer and varnish finishes while avoiding the extreme scratch pattern created by 16 or 24 grit.
Norton specifically recommends starting with 36 grit on floors that have not been refinished for a long time or have a substantial old finish.
Flooring guides also frequently recommend 36 grit as the typical first pass for standard refinishing, reserving 24 grit for substantially damaged surfaces.
Once the finish has been removed and the floor has been flattened, the sanding process moves into progressively finer stages.
The Middle Grit Is Doing Important Work
Homeowners sometimes assume the first pass removes the finish and the last pass smooths everything, making the middle stage less important.
In reality, the middle sanding stages are essential.
A 50 or 60 grit abrasive removes the deep scratch pattern created by the initial coarse sanding. At the same time, it continues flattening minor imperfections without removing timber as aggressively as the first cut.
Skipping this stage can leave coarse scratches beneath an otherwise smooth-looking floor.
These scratches may be difficult to see before finishing, particularly on pale unfinished timber. Once stain is applied, however, they can become dramatically more visible because pigment collects inside the deeper scratches.
That is one reason correct grit progression has such a major influence on the quality of the final floor.
Why You Shouldn’t Skip Too Many Grits
This is one of the most important rules in floor sanding.
Every abrasive creates scratches.
The purpose of the next finer abrasive is to replace those scratches with a smaller scratch pattern. Each subsequent stage gradually reduces them until the surface is suitable for finishing.
If you jump from something like 36 grit directly to 100 grit, the 100 grit may polish the timber without being aggressive enough to completely remove the original 36-grit marks.
Lägler specifically advises that no more than one grit should be skipped when using the main sanding machine or edger, and states that fine sanding systems should avoid skipping grit numbers entirely.
This is why an apparently faster shortcut often creates more work.
Once stain exposes deep sanding scratches, correcting the problem may require sanding the entire floor again.
Is 80 Grit Fine Enough for the Final Pass?
Often, yes.
Eighty grit is a common final abrasive for many professionally sanded hardwood floors, especially where stain will be applied afterwards.
It smooths the scratches from the previous sanding stage while leaving enough open grain for stain and finish to penetrate consistently.
Going considerably finer is not automatically better.
Very fine sanding can begin burnishing or polishing the timber fibres. That may reduce stain absorption and create inconsistent colour.
Several flooring-specific guides recommend 80 grit as a common final pass, sometimes followed by 100 grit depending on the finish and species.
The final grit should therefore be chosen with the finishing system in mind rather than simply selecting the highest available number.
When 100 Grit Makes Sense
Some floors benefit from an additional 100-grit pass.
This can be useful when:
The floor will receive a natural or very light finish where scratches would be especially noticeable.
The timber species responds well to finer sanding.
A multi-disc finishing machine is being used.
The manufacturer’s finishing system recommends a particular final abrasive.
The key is consistency.
If the main body of the floor is finished to one grit while the perimeter receives a significantly different sanding sequence, stain may absorb differently around the room.
Professional sanding therefore aims to create the same final scratch pattern across the entire surface.
Should You Use 120 Grit on Hardwood Floors?
Sometimes, but not always.
Fine abrasives around 100 to 120 grit may be useful during final preparation, screening, or specific finishing systems.
However, repeatedly sanding bare wood with extremely fine abrasives can polish the surface excessively.
Rustic Wood Floor Supply advises against going much beyond 120 grit on floors that will be stained because overly fine sanding can reduce stain penetration.
The correct final abrasive depends on whether the floor will be stained, oiled, lacquered or finished naturally.
An oil system can respond differently to the sanding scratch pattern than a surface-film finish, which is one reason Lägler emphasises careful grit selection particularly for oiled floors.
Different Floor Conditions Need Different Starting Grits
Rather than memorising one number, it is more useful to think about the condition of the floor.
A severely damaged painted floor may need something around 16 to 24 grit.
A heavily finished but otherwise normal hardwood floor may begin around 36 grit.
A floor with moderate finish and relatively little damage may begin at 40 or 50 grit.
A lightly worn floor receiving more of a surface refresh might require substantially finer abrasives.
The best starting grit is therefore the finest abrasive that still removes the existing problem efficiently.
That approach preserves timber while avoiding unnecessary sanding stages.
The Wood Species Also Matters
Different hardwood species respond differently to sanding.
Dense woods can require more aggressive abrasives or more frequent abrasive changes because they resist cutting.
Norton specifically notes that maple, for example, is sufficiently hard that it frequently requires a 36-grit starting abrasive during refinishing.
Softer species remove material considerably more quickly.
That difference matters because a sanding technique that works perfectly on oak can remove too much material from a softer timber floor.
Species, grain direction, existing finish and previous sanding history all need to be considered together.
Uneven, Cupped or Crowned Floors Need Special Treatment
Choosing grit becomes even more important where the floor is physically uneven.
Cupping occurs when board edges sit higher than their centres. Crowning creates the opposite shape, with the centre higher than the edges.
These conditions cannot simply be polished away with fine sandpaper.
Norton recommends specific sanding approaches for uneven, cupped or crowned floors, including additional passes and changes in sanding direction to flatten the timber before normal finishing passes continue.
Before sanding significant cupping, however, the source of the moisture imbalance should always be addressed.
Sanding a floor while it is still distorted from moisture can create additional problems when the timber later returns towards its normal shape.
Edge Sanding Needs to Match the Main Floor
Large belt or drum sanders cannot reach directly against skirting boards, walls and tight corners.
Those sections are completed with an edger and sometimes detail sanding equipment.
The edge sanding sequence needs to produce a scratch pattern compatible with the main floor.
If the centre is finished with 80 grit while the perimeter remains at 50 grit, the difference can become visible after staining.
Conversely, polishing the edges much finer than the centre can alter how they absorb stain.
Professional floor sanding therefore treats edge work as part of the same grit progression rather than a completely separate process.
What About Sanding Between Finish Coats?
Sanding bare timber and abrading between finish coats are different operations.
After the first protective coating has dried, very fine abrasive screens or pads may be used to lightly abrade the surface before another coat is applied.
The goal is not to remove timber.
It is to create a controlled scratch pattern that improves mechanical adhesion between finish layers and removes tiny imperfections.
Norton warns that worn-out abrasive material may dull the surface without creating the correct scratch pattern, which can contribute to finish adhesion problems such as peeling or flaking.
Always follow the finish manufacturer’s instructions because different lacquers, oils and polyurethane systems have different requirements.
Can You Sand a Hardwood Floor Too Many Times?
Yes.
Every complete sanding removes part of the hardwood surface.
Solid hardwood generally provides more usable timber than engineered flooring, but even solid boards eventually reach a point where additional sanding becomes unsafe.
Norton advises checking how much wood remains above the tongue and notes that a floor with less than approximately 1/8 inch of material above the tongue, or one where nail heads are already visible, may no longer be suitable for another conventional sanding.
This is another reason aggressive abrasives should not be used unnecessarily.
Preserving timber during each restoration increases the potential life of the floor.
Professional Sanding Is About More Than Choosing Sandpaper
The grit number matters, but the quality of a finished floor also depends on machine setup, sanding direction, machine speed, abrasive condition and how evenly the operator moves across the surface.
Keeping a sander stationary for too long can create depressions.
Uneven pressure can create chatter marks.
Worn abrasives stop cutting efficiently and generate additional heat.
Dust and debris trapped under sanding equipment can create new scratches immediately after previous marks have been removed.
For larger commercial environments, the consequences of inconsistent sanding become even more obvious because long sightlines and strong lighting expose surface defects. Professional commercial flooring Manchester services can select the sanding system, grit progression and finishing specification around the timber species, traffic level and condition of the existing commercial floor.
When to Bring in a Professional
DIY sanding machines are widely available, but floor sanding is less forgiving than many other home improvement tasks.
Once too much timber has been removed, it cannot be replaced.
Deep drum marks, uneven sanding, visible edge transitions and skipped-grit scratches frequently require additional sanding to correct, which removes even more material.
If you are uncertain about the age of the floor, how many times it has previously been refinished, or what grit should be used to begin, professional assessment can preserve significantly more of the original timber.
Experienced floor sanding Liverpool specialists can test the floor, identify an appropriate starting abrasive and progress through the grits according to how the timber is actually responding rather than relying on a fixed DIY formula.
The Best Grit Is the One the Floor Actually Needs
There is no universal sandpaper grit that works for every hardwood floor.
For standard refinishing, something around 36 grit followed by 50 or 60 grit and then 80 grit provides a useful general sequence. Floors with severe damage may require a coarser starting abrasive, while floors in better condition may allow a much finer starting point.
The most important principles are straightforward.
Start as fine as possible while still removing the existing finish efficiently. Progress through increasingly finer abrasives. Do not skip major grit stages. Finish at a grit appropriate for the stain or coating you intend to apply.
Following those principles produces a flatter, more consistent surface while preserving as much hardwood as possible for future restorations.