Sandpaper is one of the world’s most ubiquitous tools. It’s used in all types of projects, and it’s a crucial part of refinishing timber floors, decks and furniture.
There are dozens of varieties of sandpaper to choose from. The type of sandpaper you use can affect the quality of the final finish, so it’s important to understand what you’re working with.
In this article, we’ll explain how sandpaper is graded, and provide recommendations on which grit to use for sanding and refinishing timber floors.
Quick Guide: Sandpaper Types and Grit Levels
Choosing the right sandpaper depends on the material you’re sanding and the stage of your project. Coarse grits remove material quickly, while finer grits smooth and prepare surfaces for finishing.
Here’s a simple breakdown:
- Coarse sandpaper (36–60 grit) – Removes heavy coatings and levels rough timber
- Medium sandpaper (60–80 grit) – Smooths surfaces and removes minor imperfections
- Fine sandpaper (100–120 grit) – Prepares timber for coatings and finishes
- Very fine sandpaper (150+ grit) – Used between coats or for final smoothing
Professional timber floor sanding typically follows a progression from coarse to fine grits to achieve a smooth finish.
How Sandpaper Works
Sandpaper is an abrasive tool that consists of a backing paper (or cloth and mesh) with abrasive material adhered to one side. It’s used to remove material from a surface. This can strip away paint, polyurethane and other coatings, and/or make the surface smoother.
Once your timber surface has been properly sanded and smoothed, the next step is protecting it with the right finish. Water-based varnishes by Berger-Seidle or Blanchon offer a beautiful, natural look whilst still providing optimal protection. Natural oil systems such as WOCA wood oils are also commonly used after sanding to nourish the timber and protect the surface from wear.
How Sandpaper Grit is Measured
The abrasiveness of sandpaper is measured by its “grit”. Grit is a measure of how many of the abrasive particles can pass through a 1 square-inch filter. Therefore, the lower the number, the more abrasive the sandpaper is.
For example, 40 grit sandpaper is very coarse, while 800 grit sandpaper is very fine.
These abrasive particles are made from a variety of materials. The common ones include:
- Aluminium oxide – Aluminium oxide is the most common abrasive. It’s cheap and effective, but it wears out quickly. Suitable for soft materials like timber.
- Silicon carbide – Silicon carbide offers extra strength and longevity. It’s hard and best suited for materials like glass.
- Zirconia – Zirconia sandpapers offer excellent performance and longevity. They’re suitable for most types of soft and hard materials.
- Ceramic – Ceramic is the toughest and highest-performing abrasive for sandpaper. It resists dulling and build-ups of heat, which make it effective for all types of materials.
Ceramic sandpapers are some of the most effective abrasives on the market. The hardness of ceramic particles means the sandpaper lasts longer and that it’s resistant to heat. We recommend using ceramic sandpaper for tasks like refinishing timber floors with commercial machinery.
What Are the Different Types of Sandpaper?
Sandpaper can be categorised by both the abrasive material used and the backing type. Each type is designed for different tasks.
Cloth-backed sandpaper
Often used with belt sanders and professional floor sanding machines as the cloth backing provides strength and durability for heavy sanding jobs.
Paper-backed sandpaper
This is the most common type used for hand sanding and orbital sanders. It’s flexible and affordable, but it can wear out faster during heavy sanding.
Mesh sandpaper
Mesh abrasives allow dust to pass through the sanding surface, which makes dust extraction easier and reduces clogging when sanding timber floors.
Foam sanding pads
Foam-backed abrasives are typically used for detailed sanding, curved surfaces, or between coats of finishes.
Sandpaper Grit vs Sandpaper Grade
Sandpaper grit is a measure of the size of the abrasive particles. Sandpaper grade is a description of the coarseness of the sandpaper. The grades run from extra coarse through to ultra fine.
When choosing sandpaper for your project, it’s usually more important to pay attention to the grade than the grit.
For example, we’d recommend using a coarse grade of sandpaper for the first pass when sanding an outdoor timber deck. It doesn’t matter whether you use 40 grit or 50 grit paper, as long as it’s somewhere in that range.
Choosing the Right Sandpaper for Your Project
Sandpaper is useful for removing material and coatings, refining shapes and finishing surfaces. The table below shows a rough guide on how each grade of sandpaper is commonly used:
|
Sandpaper Grade |
Sandpaper Grit |
Application |
|
Extra Coarse |
24-36 |
Stripping old finishes |
|
Coarse |
40-50 |
Bulk sanding, removing old finishes, removing imperfections, shaping wood (e.g. sanding sharp edges on furniture) |
|
Medium |
60-80 |
Removing minor imperfects in floors, removing thin coatings of paint |
|
Fine |
100-120 |
General sanding, prep for water based polyurethane and other wood finishes |
|
Very Fine |
150-220 |
Fine surface prep for penetrating wood oils |
|
Extra Fine |
320-360 |
Sanding between coats of wood treatment or paint |
|
Super Fine |
400-600 |
Sanding and polishing raw or finished timber, wet sanding certain types of timber finishes |
|
Ultra Fine |
800+ |
Sanding and polishing raw or finished timber, wet sanding certain types of timber finishes |
Still unsure which sandpaper grit to use? Watch this step-by-step guide to see exactly how to choose the right grit for your project.
Which Sandpaper Do I Need to Refinish Timber Floors?
If you’re using commercial equipment to sand your floors, we recommend using the following sandpaper grits:
- First pass – 40 grit
- Second pass – 60 grit
- Third pass – 80 grit
- Buffing – 100 to 120 grit
- Before final coat – 150 to 200 grit
You can use these grades of sandpaper for timber floors, decks and furniture.
Don’t throw away your worn-out sandpaper screens! Old screens are mostly smooth, making them good for polishing your floors in between coats of your chosen finish.
After the final sanding stage, the timber is ready for sealing or oiling. Many DIY renovators choose natural products, such as WOCA floor oils, designed specifically for timber floors to enhance the wood grain because they penetrate the timber and enhance the wood grain. Another popular choice is water-based finishes such as the AquaSeal range by Berger-Seidle or for a more ‘Nordic’ look the Blanchon Iceberg polyurethane is the way to go.
See our complete guide on refinishing your timber floors for more details.
How Much Sandpaper Do You Need for Floor Sanding?
The amount of sandpaper required depends on the size of the floor and the condition of the timber. Larger areas and heavily coated floors will require more sanding belts and discs.
The guide below shows a typical sandpaper estimate for floor sanding projects of different sizes.
This is a general guide only. Each timber floor is different, and factors such as old adhesives, coatings, and timber hardness can affect how quickly sandpaper wears out.
A Note on Sanding Equipment
The type of sandpaper you choose also depends on the machinery you’re using. Commercial sanders that are used for refinishing timber floors require specific sizes of sanding pads and belts.
Common Sanding Mistakes to Avoid
Even experienced DIY renovators can run into issues when sanding timber. Avoiding these common mistakes will help achieve a smoother finish.
Skipping grit levels
Jumping from very coarse sandpaper directly to fine sandpaper can leave visible scratches in timber. Always progress gradually through grit levels.
Using worn-out sandpaper
Old sandpaper loses its cutting ability and can burnish timber rather than sanding it properly.
Applying too much pressure
Let the abrasive do the work. Excess pressure can damage sanding equipment and create uneven surfaces.
Sanding against the grain
Whenever possible, sand timber with the grain to reduce visible scratches and achieve a smoother finish.
Using the wrong equipment
Large areas like timber floors require professional sanding machines. Smaller tools are better suited for furniture or detailed sanding work.
Tackle Your Next DIY Project With Quicksand Supplies!
Sanding and refinishing timber floors takes a little bit of elbow grease and a lot of sandpaper, but it’s something you can do yourself!
If you’re unsure where to start, Quicksand Supplies provides everything you need to sand your floors, decks and timber furniture.
We carry a range of sandpaper products that are compatible with commercial sanding machinery including hire machines. Our sandpaper discs and belts are sized to suit professional floor sanders and floor edgers. These can be hired from stores like Bunnings, and then you’ll have everything you need to refinish your floors.
For everyday cleaning after refinishing, check out our range of spray mops designed to care for timber floors without damaging your new finish.
Contact our team if you have any questions – we can provide advice on sandpaper, hiring equipment and the best floor coating systems for your timber floors and furniture.
Frequently Asked Questions
What do sandpaper grit numbers mean?
Sandpaper grit numbers refer to the size of abrasive particles. Lower numbers indicate larger particles and more aggressive sanding, while higher numbers produce a finer finish.
What grit sandpaper should I use for wood?
Most timber projects start with 40–60 grit to remove coatings, followed by 80 grit to smooth the surface and 100–120 grit before applying finishes.
What is the difference between sandpaper grit and grade?
Grit refers to the number used to measure abrasive particle size, while grade describes the overall coarseness category, such as coarse, medium, or fine.
Can I use the same sandpaper for floors and furniture?
Yes, the same grit progression can be used for both. However, floors often require belt sanding machines while furniture is usually sanded by hand or with orbital sanders.