How To Sand a Deck

While solid stain wooden decks decking requires little maintenance, there are still actions you need to do to keep your stained deck looking as good as new.

Sanding your deck is a vital step in prepping it for stain, so take your time and do it right.

When a deck is first built, nothing protects the wood, and leave it this way, and it will wear, and the color can fade.


While the worn color looks nice, can be lovely, a protective stain or finish will apply the life of your wood deck in its original color or a color of your choice. But first, you must prepare your deck for the stain.

Sanding a wood deck smooths out the surface and removes splinters, and you can find it extends the life of your stain by doing so.

In our guide, you can learn more about what grit sandpaper for deck sanding you need. You’ll learn the right tools and the recommended sanders for the job, and last, the minimal effort step-by-step guide on how to sand your deck to preserve the surface and the wood grain. (Read Do You Have To Sand Between Coats Of Polyurethane)

What Is the Best Tool to Sand a Deck?

Every external wooden construction has one thing in common with its wood surface. They need maintenance.

Most decks are no different and can be worse because of the large surface area. When you want a smooth surface, the best choice of tool can be your orbital floor sander.

A random orbital sander is the most effective sander since they are easy to use and highly effective. The abrasive sandpaper moves in an uneven pattern rather than a line or circle on your deck refinishing project and leave fewer marks.

You can sand your wooden deck in several ways. It ranges from hand sanding, which takes time, and you can end up using a drum sander, as used by professionals to finish hardwood floors. The latter isn’t recommended when compared to the control you have with your orbital hand sander.

Compared to orbital sanders, belt sanders often use coarse sandpaper and are highly aggressive on the wood you are sanding. Orbital sanders are easier to use, and you can use their compact form to sand your railings.

Types of Random Orbital Sanders

For your deck restoration endeavor, you have several types of random orbital sanders. Selecting the power source is the start of picking the right sander type.

Pneumatic Random Orbital Sanders: Being powered by compressed air, you’ll need air compressors and hoses.

Auto body repair firms use these and while they can work, dragging a hose behind you isn’t practical. They can also blow the wood fibers and wood dust into the air and make it hard to breathe and see.

Electric Random Orbital Sanders: An orbital sander of this type is the best choice for deck sanding. Electric sanders vary on 110-volt home power, with varying amperage, or you can find them with rechargeable batteries.

For most projects, you’ll want one of the following sizes to deal with your deck floor.

  • 3-inch: Suitable for DIY woodworkers who need to sand in small, tight areas where a belt sander isn’t useful.
  • 5-inch: Ideal for do-it-yourself woodworkers who need to cover larger areas with less force and lots of control.
  • 6-inch: Suited for larger tasks such as a deck sander. Using sanders of this size means you could end up with more sanding dust, yet you could finish sanding a deck in less time and reduce the amount of elbow grease needed.

wood deck

Should You Sand a Deck Before Staining?

The answer to sanding a deck before staining is “it depends.” A light sanding won’t hurt the deck, and the degree you need to clean surface will depend on the decking’s age and condition.

Sanding is more for feel rather than preparing for a fresh coat of stain.

Before you get going, it is recommended to use a light wood stripper and then use pressure washing to clean the surface and open up the wood grain for staining.

After washing the deck, and is still feels rough, do some sanding once it has thoroughly dried.

Can I Use a Floor Sander to Sand My Deck?

The short answer to this question is that it depends on the situation. There are a lot of opposing views on whether floor sanders can sand your deck, and both sides have valid points.

However, in reality, this isn’t the best way to sand down your deck. We’ll go over the best way for preparing your deck for re-varnishing before showing you how to use a floor sander if that’s all you have.

1. Choose Your Stain or Sealant

For refurbishing decks, a choice of stains and sealants are available. Decide whether your deck needs sealing and which exterior stains and sealers to use while learning how to refinish deck boards on your wood deck surface.

  • Pour a few droplets of water onto a deck board to carry out a water drop test.
  • If the board absorbs the water, you need to seal your deck for protection. If the water beads on your wood deck, the wood is probably sealed and only requires cleaning unless you wish to change its appearance.

Stains offer a wooden deck a fresh look by coloring the wood once the deck dries, and Semitransparent stains or sealers will allow the wood grain to show. You’ll find these are also best used on pressure-treated lumber. Consider adding a wood brightener before you add any finish.

Clear finishes like varnish or polyurethane should be avoided since they can degrade when exposed to sunlight.

clean deck

2. Clean and Prepare Your Deck

Take care to clean and prepare your deck and ensure you get the best results before your deck project refinishing.

  • First, you need to inspect the deck, handrails, and steps.
  • Replace damaged boards and make sure no nails or deck screws stick up.
  • Fill holes, cracks, or scratches using epoxy wood filler and a putty knife.
  • Clear the deck of outdoor furniture, toys, plants, and other objects.
  • Clean your deck with a biodegradable anti-mildew treatment deck cleaner to kill mildew.
  • Scrub with a stiff bristle brush.
  • Use a power washer on your deck surface. Power washing can remove dirt, grime, and possible mildew stains that could have set in. It is much easier to let your pressure washer deal with these than trying to sand them out. (Use the pressure washer on low with the fan spray).
  • Apply painter’s tape between your deck and home.
  • Pressure washing is the best choice as you know a power washed deck will be spotless.

Note: Don’t use metal brushes on softwood decks or soft woods such as cedar or redwood, as you could damage the soft wood fibers.

3. Sand the Deck

If you plan to stain the deck, sand the surface first to let the coating penetrate the wood.

  • To sand your deck, you can rent an orbital flooring sander and enough 80- and 100-grit sandpaper.
  • Start sanding the entire surface to remove any old shine and smooth any uneven places on decking planks with an orbital sander and work to a finer grit for a smooth finish.
  • First, using 80-grit sandpaper, sand the entire deck—sand in corners and under rails with a palm sander.
  • If you plan to refinish the railing, this is a good time to sand it with a palm sander as your paint remover. If you need to remove a thick coat of finish on your railings, use 100-grit paper, and you’ll likely need two passes, one with 80-grit paper and the other with 100-grit. To finish, you could need to run over the railing and not use sandpaper grits and your power sander, but a sanding sponge.
  • Vacuum the deck boards after you have finished sanding to ensure no dust sticks to the new surface.
  • When sanding treated wood, always wear a dust mask and safety goggles to protect your eyes. If you are using a handheld orbital sander, it’s recommended wearing knee pads for comfort.

4. Refinish Your Deck

Ensure the deck dries for two days before applying stain or sealant while learning how to restain a wood deck. (Learn How To Paint Over Stained Wood)

Vacuum or blast the dust off the deck using a leaf blower. Sand with 100-grit sandpaper once more, then clean off the dust.

Begin by using a paintbrush to apply stain or sealant to the handrails, starting at the top and working your way down to the deck surface. You can also use a paint sprayer to apply the stain.

Apply oil-based stains with a natural bristle paintbrush and water-based stains with a synthetic bristle brush.

Stain or seal the surface decking boards using flat paint-pad applicators.

As desired, apply a clear finish, semi-transparent stain, or UV-blocking varnish. Most stains can be rolled or sprayed with a garden sprayer to save time.

Because stain takes time to sink into the wood yet dries quickly, it’s best not to apply it in direct sunlight, although you need dry weather. Please stay off the deck for a full day to ensure it dries completely without marking.

Remove the painter’s tape, reposition the furniture, and enjoy the results of your deck restoration.

To avoid tracking through the wet stain, apply deck stain with your exit in mind, such as ending at the steps after your final pass.

How To Sand a Deck (1)

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