Sanding a wooden floor is one of the most effective ways to bring it back to life. A tired, scratched or uneven floor can often be transformed with the right sanding process, followed by a suitable finish to protect the timber and bring out its natural character.
However, one of the most common mistakes with floor sanding is choosing the wrong grit, or skipping through the sanding stages too quickly. The grit sequence matters. It affects how well old coatings are removed, how smooth the timber becomes, and how even the finished floor will look once oil, lacquer or another protective finish is applied.
At Advantex Cleaning, we restore wooden floors for homes and commercial spaces across Bristol, Bath, Somerset, Gloucestershire and the wider South West. This guide explains how floor sanding grits work, why each stage is important, and why professional floor sanding is not simply a case of running a machine over the boards.
What Does Sanding Grit Mean?
Sanding grit refers to the coarseness of the abrasive used to sand the floor. The lower the number, the coarser the grit. A coarse grit removes more material and is used for heavy sanding, old finishes, scratches and uneven boards. A higher grit is finer and is used to smooth and refine the surface before finishing.
For example, 24 grit is very coarse, while 120 grit is much finer. A wooden floor is usually sanded in stages, moving from coarse to medium to fine grits. This gradually removes damage and old coatings without leaving deep sanding marks in the timber.
Choosing the right starting grit depends on the condition of the floor. A heavily worn floor with old varnish, deep scratches or uneven boards will usually need a much coarser starting point than a floor that only needs a light refresh.
Why The Grit Sequence Matters
A good floor sanding result depends on working through the correct grit sequence. Each stage removes the scratches left by the previous grit. If you jump from a very coarse grit to a very fine grit too quickly, the finer abrasive will not be able to remove the deeper scratch marks.
This can lead to visible lines, uneven patches and a poor final finish, especially once the floor is sealed. Finishes can highlight sanding marks rather than hide them, which is why careful preparation is so important.
A proper grit sequence also helps create an even surface, opens the timber correctly for the chosen finish, and allows oils or lacquers to bond as intended.
Common Floor Sanding Grits And When They Are Used
Every floor is different, but the following grit guide gives a useful overview of how the sanding stages often work.
16 To 24 Grit: Heavy Sanding For Damaged Floors
Very coarse grits such as 16 or 24 grit are used when a floor needs serious restoration. This may include removing thick old coatings, heavy staining, adhesive residue, cupping, uneven boards or deep scratches.
This stage removes material quickly, so it needs to be handled with care. Starting too aggressively on a floor that does not need it can remove more timber than necessary. However, for badly worn floors, a coarse first cut may be needed to get the surface back to a level, workable condition.
36 To 40 Grit: Removing Old Finish And Levelling The Floor
A 36 or 40 grit is often used as an early sanding stage for floors with old varnish, paint, marks or general wear. It is still coarse, but less aggressive than 16 or 24 grit.
This stage helps remove remaining finish and begins to level out the floor. It is commonly used on older wooden floors that have not been sanded for many years, or where the surface is uneven and heavily marked.
50 To 60 Grit: Smoothing After The First Cut
Once the initial sanding stage has removed the worst of the old coating and damage, the floor is usually sanded with a medium grit such as 50 or 60.
This stage begins to remove the deeper sanding marks left by the coarser grit. It also helps refine the surface and prepare it for finer sanding. Skipping this stage can leave visible scratches in the finished floor, so it plays an important role in achieving a professional result.
80 Grit: Refining The Timber
An 80 grit is often used as a key finishing preparation stage. By this point, the floor should be clean, level and free from old coatings. The 80 grit helps refine the timber further, removing the marks left by previous sanding stages.
For some wooden floors, particularly softer timbers, 80 grit may be close to the final sanding stage depending on the chosen finish. However, many floors will still benefit from a finer final pass.
100 To 120 Grit: Final Sanding Before Finishing
Finer grits such as 100 or 120 are often used before applying the final finish. This helps create a smoother surface and improves the overall appearance of the floor.
The correct final grit depends on the type of timber and the finish being applied. Sanding too finely can sometimes close the grain of the wood too much, which may affect how well certain oils penetrate. Sanding too coarsely can leave marks that show through lacquers or lighter finishes. This is one of the reasons professional judgement is so important.
What About Edges And Corners?
Floor sanding is not just about the main open areas. Edges, corners, stairs and areas around pipes or fireplaces all need careful attention.
Professional floor sanding usually involves different machines and tools, including belt sanders, edging sanders and detail sanders. The grit sequence still matters in these areas. If the edges are sanded differently from the main floor, they can look uneven once the finish is applied.
A well-restored wooden floor should look consistent across the whole room, not just in the easy-to-reach areas.
Can You Sand A Wooden Floor Yourself?
DIY floor sanding is possible, but it is easy to damage a floor if the wrong grit or machine technique is used. Common DIY issues include drum marks, uneven sanding, over-sanding, visible edge lines, missed old finish, and scratches that only appear once the floor has been sealed.
Wooden floors can only be sanded a certain number of times during their lifespan. Removing too much timber unnecessarily can shorten the life of the floor. This is particularly important with engineered wood flooring, where the top layer of real wood may be much thinner than solid timber.
Professional wood floor sanding is often the safer option if the floor is valuable, heavily worn, uneven, previously coated, or part of a larger restoration project.
Dust-Free Floor Sanding
Modern professional floor sanding is much cleaner than many people expect. At Advantex Cleaning, we use professional sanding equipment designed to reduce dust during the restoration process.
While no sanding process can be completely dust-free in every situation, high-quality extraction makes a significant difference. This helps protect the property, improves working conditions, and supports a cleaner finish before oils, lacquers or sealers are applied.
Choosing The Right Finish After Sanding
Once the floor has been sanded through the correct grit sequence, it needs to be protected. The right finish depends on the look you want, the type of timber and how the room is used.
Options may include oils, hardwax oils, lacquers or specialist commercial finishes. Some clients prefer a natural matt look, while others want more depth, warmth or sheen. The finish should suit both the appearance of the floor and the practical demands of the space.
A busy hallway, commercial floor or family kitchen will usually need a hardwearing finish that can cope with regular foot traffic. A bedroom or low-use room may allow for a different approach.
Professional Floor Sanding And Restoration From Advantex Cleaning
The right sanding grit sequence can make the difference between a floor that simply looks sanded and a floor that has been properly restored. Each stage has a purpose, from removing old coatings and damage to refining the timber and preparing it for a durable, attractive finish.
At Advantex Cleaning, we provide professional wooden floor sanding and restoration in Bristol, Bath, Taunton, Weston-super-Mare, Somerset, Gloucestershire and all across the South West. We assess each floor carefully, choose the right sanding process, and use professional equipment to restore the surface with care.
Whether your wooden floor is scratched, dull, uneven, stained or simply ready for a new finish, our team can help bring it back to life. From the first sanding cut to the final protective coating, we focus on achieving a clean, even and long-lasting result.