No matter how durable and carefully you maintain them, hardwood floors can get scratched and dented from constant use. The good news is that you can restore their smooth appearance by sanding them. But how often can you sand them?
In general, you can sand hardwood floors 5-10 times. However, the actual number depends heavily on the thickness and quality of the hardwood. Solid hardwood is very resistant to sanding and can withstand sanding up to 10 times. Engineered hardwood, on the other hand, is not as strong, so it can only be sanded up to five times.
Read on to learn more about the factors that can limit the number of sanding operations on your hardwood floor.
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Factors to Consider When Sanding Hardwood
When sanding a piece of hardwood, many factors need to be considered. This is because different wood species have different sanding tolerances.
Thicker and stronger hardwood can be sanded more frequently than hardwood with a slimmer and weaker construction. Keep reading as I discuss more about it.
How thick the hardwood layers are
Wood floors come in different types and thicknesses, which affect their lifespan and, of course, sanding limits. Solid hardwood consists of a single plank, while engineered hardwood consists of two pieces of wood.
Hardwood floors have a thick and sandable plank, which is also more durable. They have a feature called the wear layer. The wear layer of hardwood flooring is the protective layer on top of the flooring, preserving it from wearing out.
Engineered floors are less sandable, and some of them are not sandable at all—not ready-made. That is because of the thickness of the wear layer, which varies among different wood species.
Ready-made engineered hardwood can have a wear layer of up to 5/6″, while solid flooring averages 5/6″. The thickness of the wear layer determines how many times you can sand the floor. If, for instance, the wear layer is less than 1/16″, you should avoid sanding it and consider replacing your floor.
Veneered floors are much thinner and generally unsuitable for sanding. If you have such a flooring, you should ask the manufacturer whether the surface is sandable and how many times you can sand it.
If you don’t know what kind of hardwood your floor is made of, this video can help you determine the type:
As a rule of thumb, solid hardwood can be sanded 5-10 times, while engineered flooring can be sanded up to 5 times.
Each time you sand your floor, you remove 0.75 to 1 mm (0.03 to 0.04 inch) of the wood surface. This number gives you an approximate idea of how many times you can sand your floor based on the thickness of the wear layer. For example, if your wear layer is 4–6 mm (0.16 to 0.24 inch) thick, you can sand it 3 to 6 times.
How to determine the thickness of the floor
If you want to know how thick the wear layer is, you can inspect the floor from the side or pull out a floor vent. You should perform any measuring method at the floor register. You can also remove the transition strips to measure the thickness. Look for the tongue of the plank, and anything you see above the tongue is sandable.
Another way to check the thickness of your parquet floor is with the business card test. Find a gap between any two boards and put a business card in between. Mark with a pencil the spot where the card meets the floor edge. This point will show the thickness from the top of the board to the tongue.
You can also use feeler gauges to measure the thickness accurately. For example, this stainless steel feeler gauge available on Amazon.com is made of stainless steel and comes with 32 blades of different thicknesses.
Hardwood species and how hard it is
Hardwood floors are made from various wood species—red oak, white oak, walnut, cherry, ash, to name a few.
The Janka hardness scale tells you how hard the wood is and gives you a better idea of how much you can sand the wood. The higher the wood species scored on the Janka scale, the harder the wood.
And the softer the wood, the more dents and scratches it will have, requiring more frequent sanding.
Your sanding skills
Not everyone can sand hardwood floors, no matter how many YouTube videos they watch or tutorial articles they read. It’s a skill that you should learn through years of experience.
The sander needs to know what grit to use and what sanding belt or disc is better for the floor. They should also consider how much wood they remove with each sanding, which is crucial for extending the floor’s lifespan.
It’s also important to know all types of flooring wood and understand to what extent they can withstand sanding. If the person sanding your floors lacks current knowledge of the craft (maybe they are old-schoolers who think every floor is like the solid wood floors that belonged to the ’50s and can be sanded multiple times), they may potentially ruin your floors.
The condition of your hardwood floor
The depth of scratches on the floor and its overall condition determines how much wood should be removed with each sanding, affecting the number of sanding operations. The more damaged the surface is, the more wood you will have to remove during sanding, reducing the thickness.
That’s why it’s essential to always maintain your hardwood floor as much as possible. Even if you sand your floor, you can do more if it’s minimally damaged only.
Type of sandpaper
Different sandpapers and abrasives have different hardness levels with different grain shapes. Some grains have sharper edges, which wear the wood differently each time. Also, the speed of sanding and cutting through the wood surface will be different for each sandpaper.
Motor sanders, belt sanders, disc sanders, and regular sandpaper have different abilities, efficiencies, and speeds. The sandpaper you use determines how much wood you remove each time and how much wood is left for future sanding.
If you’re uncertain how much wood the sander removes, you can try it on a small piece of hardwood in a hidden spot of a room. Then measure the performance to get a better picture of the entire process.
Manufacturer recommendations
Even if you know the exact wear layer of your engineered floor, it’s always a good idea to follow the manufacturer’s recommendations. They will tell you how often you should sand your engineered floor and how to do it for better results.
For example, some manufacturers recommend sanding the floor immediately after installation and then oiling it.
If you’re unsure how well your wood will withstand refinishing, it’s wise to ask for professional help. Sanding a thin hardwood floor leads to splintering, exposed nails, and unusable and unsafe floors. Even if the wood is too thin to sand, the experience of a professional can help you sand your floor in the least damaging way.
Conclusion
The primary factor that determines how often you can sand a hardwood floor depends on the type of hardwood and its thickness. You can determine the thickness of the hardwood by looking at the wear layer.
In general, solid hardwood can be sanded 5-10 times, while engineered hardwood can be sanded up to 5 times.
However, other factors can limit this number. For example, if the wood has deep scratches and dents, you will need to go deeper and remove much more wood during sanding, reducing the thickness.