How to Sand a Wooden Deck

Whether your deck is in dire need of repair or you’re just looking to give it a new coat of paint, sanding is the first step in refinishing an outdoor wooden deck. The process of sanding a deck before refinishing will remove the old top coat and expose the original, untreated wood. This allows you to refinish that layer in order to achieve a beautiful finished product.  This article will break down the process for you, how to sand a wooden deck before refinishing with the right type of decking sander.

Types of Decking Sander

There are many types of petrol, gas and electric power sanders, but they all fall into one of two categories: rotary or random orbital available for using on a deck. Here we discuss some of the best sanders to use on decking.

Floor Sander

A floor sander is a heavy-duty power sander with a wider head than the sanding pad on a random orbital sander. The wider head allows for the floor sander to cover more surface area in less time. The downside of using a floor sander on your deck is that the spinning head (which is usually enclosed) can kick up dust and debris, irritating you or people around you as you work. Also, the floor sander’s length means that it will hit your deck’s edges, making it difficult to get into corners and around obstacles.

Random Orbital Sander

Random orbital sanders are the best type of petrol, gas and electric power sander for sanding a deck. These sanders have a spinning, spinning pad that is held away from the wood by a frame. When you switch the power on, the spinning pad moves forward quickly and comes back to its starting point, creating a smooth finish in seconds. Simply put, a random orbital sander does not kick up dust and debris, it does not require you to bend over, and it is easy to use.

Rotary sanders

Rotary sanders are best for quick, aggressive gouging and shaping of wood surfaces. These power tools also work well for removing surfaces due to rot or other forms of decay. The downside is that rotary sanders are not as smooth and soft as random orbital sanders. They can also be harder to control, requiring more finesse than a floor sander or an electric/petrol power sander.

Belt Sander

The belt sander is another good choose for stripping or refinishing wooden surfaces that are very rough. A belt sander is a heavy-duty power sander that spins a sanding belt which is wrapped around the machine’s base and controlled by the motor. The belt spins faster than a random orbital sander and is harder to control, but it creates a smooth finish quickly.

What Type of Sandpaper For Decking?

Type of Sandpaper For Decking

If you are sanding a deck, you will need a certain type of sandpaper for the job. Fiberglass sandpaper works well to sand down the surface of a deck, or you can use grade 80 sandpaper. It all depends on the kind of finish you want.

Fiberglass Sandpaper

Fiberglass sandpaper is a course-grit sandpaper that is used to repair and refinish wooden decks. It is course enough to rip away old layers of the wood, but thin enough that it does not remove too much material at one time.

Grade 80 Sandpaper

Grade 80 sandpaper is a very soft sanding material made from calcium buffered alumina (cab) and contains a small amount of special fiberglass that acts to reduce friction between the sandpaper and the deck. It is made of compressed aluminum oxide which is harder than steel, but not as hard as a diamond. This sandpaper reduces damage to the wood being sanded, while still getting the job done quickly.

How to Sand a Wood Deck

If you want to give your deck a new look, you can sand it down and paint or stain it. Sanding a deck is actually easier than you may think and can be done by hand or with an electric or petrol power sander. This is not difficult to sand a deck, you just need the right type of sander, the right type of sandpaper, and just follow a few steps.

1. Wash the Wood

How to Sand a Wood Deck

If the wood on your deck has been exposed to rain or other water, first you must wash it off before you start sanding. Rinse the deck with clear water to remove all dirt and debris, then use a scrub brush to remove any stubborn material. Let the deck dry completely before you start sanding.

2. Repair the Surfaces

After cleaning and washing the deck wood, if there are any rough edges or broken sections, you should fill them in before sanding begins. Fill holes with wood putty, then let it dry before doing anything else. Sand down the deck to create a smooth surface, then sand the deck again to remove any small cracks.

3. Sand the Deck Surface

Use the right type of sander to sand down the deck surface. A floor, electric or petrol-powered power sander works best, but a random orbital sander can be used to sand down your deck. With any sander, be sure to use the right kind of sandpaper. If you are using an electric sander, choose a coarse layer paper (fiberglass or grade 80) and finish off with a fine grit paper (400 or 00).

It is important to sand in one direction (either clockwise or counterclockwise) when using an electric sander, because if you move the sander back and forth, you may leave scratch marks. With the random orbital sander, use the same side of sandpaper on each pass, going in one direction until you achieve your desired result.

4. Vacuum the Deck Surface

Once you are done sanding, vacuum the deck, including the edges and all corners to remove any dust or debris. You can also use a wet-vac machine to get into the nooks and crannies of your deck. This will help you get rid of any dust or debris that is still there, watch this video for more information.

Tips and Warnings

If you are going to sand a deck with an electric sander, remember to wear a dust mask or respirator. The flying dust and debris can be dangerous to your lungs, especially if you are prone to allergies or asthma. Also, it is recommended that you wear protective glasses when using an electric sander. If you are sanding with a floor sander, make sure to work in an area with plenty of ventilation and keep your legs as far away from the spinning head as possible.


In conclusion, the process of how to sand a wooden deck is a very quick, easy, and affordable way to transform your deck into a masterpiece. The process is easy, and you can sand almost any wood surface. I hope this article has inspired you to give your deck a new look and make it the centerpiece of your yard. If you like how to sand a deck article , please share it! Don’t forget to join our Facebook group and follow our website.

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