How to Sand a Deck

If you’re planning to stain your deck, then you probably know that you have to sand it first so that the product can penetrate the hardwood better. If the boards aren’t properly sanded and prepared, they won’t absorb the stain, and you’ll be left with a mess in your hands. Moreover, you can improve the smoothness of the finish by taking the time to do this.

However, you have to be extra careful with your technique and the grit of the sandpaper you use. If you sand too much, the pores of the wooden surface will shrink, and again, won’t absorb the stain correctly.

To sand a deck, you will need to gather a few tools, prepare the wooden surface, and then follow five main steps: put your PPE on, attach the sandpaper, sand the deck, switch tools to sand the railings, and clean up the dust.

Below you’ll find everything you’re going to need to sand your deck, step-by-step instructions, and some tips to achieve the best results. Let’s get started!

What You’re Going to Need

Equipment and Tools

  • Hard bristle broom
  • Mop
  • Scrub brush
  • Bucket
  • Orbital sander, oscillating flooring sander, or belt sander
  • Palm sander
  • Vacuum or leaf blower

Optional/If needed:

  • Paint scraper
  • Power washer
  • Screwdriver or drill
  • Hammer


  • Mild dish soap
  • Sandpaper (60-grit or 80-grit)

Optional/If needed:

  • Wood cleaner and brightener
  • Deck screws
  • 100-grit sandpaper

Personal Protection Equipment

  • Gloves
  • Safety goggles
  • Dust mask

Preparing a Deck for Sanding

Any good remake begins with a good wash to achieve the best results. To stain your deck, you have to sand it, but before you can do that you have to clean it.

Depending on the stain brand you’ve bought, you might have to use different cleaning methods, so make sure to check the manufacturer’s instructions before you start. Most of the time it will require power washing or simply giving the deck a thorough sweeping.

Power Washing

When power washing, you should be very careful with the setting and handling of the sprayer. Softwoods like pine or cedar can suffer great damage from strong settings, which is why we recommend using a wide fan nozzle with pressure no higher than 2,000 psi. Hardwood decks, on the other hand, can take a turbo nozzle with a pressure of 3,000 or 4,000 psi.

Regardless of the material of your deck, you should always keep your power washer constantly moving, so it doesn’t cut into the wood and damage it. We like to test the washer out on a less visible spot and see how the wood reacts. If you notice that the wood fibers start to lift, it’s a sign to back off.

Sweeping the Deck

Sweeping your deck ensures that you have a clean surface to work with, so get rid of any mold, leaves, and other debris with a hard bristle broom.

Then, grab a bucket, fill it with warm water, and add a few squirts of mild dish soap. Mix it all together and use the solution to mop the deck. Rinse it with clean water and let it fully dry for at least a whole day. Meanwhile, you can use a paint scraper to remove any debris that’s stuck in the gaps between the boards.

Applying Wood Cleaner and Brightener

Another option to prepare your wood deck is to apply a wood cleaner and brightener. While this step is completely optional, it can make the rest of the process go quicker.

Following the instructions on the bottle, mix the cleaner and soak the wood. Let it sit for approximately 15 minutes and then, with the help of a stiff bristle brush, scrub the wooden surface.

Bear in mind that you might need to repeat this process a few times to remove all the dirt.

Repairing the Surface

You need to make sure that there aren’t any nails and screws that have popped out of place because they can rip your sandpaper when you’re sanding. Moreover, very old fasteners may need to be replaced, whereas any loose boards might need new ones.

So, you should pound nails down with a hammer and drive in screws, always making sure they’re all secured below the level of your deck.

How to Sand a Wood Deck

Now that the tedious cleaning and waiting for the wood to dry is out of the way, it’s time to roll up your sleeves and get down to work.

To sand a wood deck you can use an orbital sander, an oscillating flooring sander, or a belt sander. You can do it by hand as well, but for an even finish, we recommend using one of the aforementioned power tools. If you don’t own one, you can rent them at any home improvement store.

The key here is to choose the right sandpaper grit. You should avoid finer-grit sandpapers because they’ll clog the pores and prevent the wood from absorbing stains and sealers.

Here’s what you have to do to sand your deck:

  1. Safety first! Put your PPE on.
  2. Attach 60-grit to 80-grit sandpaper in your power sander.
  3. Sand the whole wooden surface while applying medium pressure on the sander to remove any scratches, splinters, and old finish.

If your deck is softwood, be extremely careful with the pressure because they don’t need an aggressive approach. In fact, you can damage them if you apply too much pressure.

  1. Sand the railings, and those tight corners and hard-to-reach areas under benches where other sanders can’t go with a palm sander and the same grit sandpaper of your power sander.
  2. If necessary, you can follow up with another pass with 100-grit sandpaper. This is completely optional and should be done only if there’s some stubborn, old finish you couldn’t remove completely with the 60-grit or 80-grit.
  3. Vacuum the wood deck to remove dust, or just blow it off with a leaf blower.

Now you can stain or seal your deck! We recommend doing it immediately after sanding. If you wait, even if it’s just a day, the deck wood can get wet or dirty again, which means you’ll have to clean it all over again. Remember that both stain and sealer require a spotless surface for proper adherence.

Frequently Asked Questions

How often should I sand my wood deck?

This will depend on the type of stain you apply on your deck since the main reason for sanding is to prepare the surface for the stain.

Water-based stains typically last about 2 to 3 years and require complete removal of the old stain before a new coat can be applied. Oil-based stains, on the other hand, can last 1 to 2 years, but they don’t require sanding before a new coat.

How long does it take to sand a deck?

There are many factors that can have an impact on the time it takes to sand your deck. The size is obviously the main one, but there is also the type of sander you use and the condition of the wooden boards. For example, using an orbital floor sander will make the job go much faster than using a palm sander. Moreover, newer decks usually require a single pass, whereas older ones might need up to three passes.

To give you an approximate idea, 100 square feet can require at least 5 hours if you take into account roughing the railings, edges, and so on.


We’ve mentioned this a few times already, but it doesn’t hurt to say it once more: staining is the best way to maintain your wooden deck, and for that, you need to do some sanding first.

While the whole process might take a couple of hours, it’s essential that you do it properly in order not to damage the wood.

Luckily, we’ve given you all the step-by-step instructions and tips you might need so you can get right down to work!

Liam Weissman

Hello and welcome to PowerToolGenius! My name is Liam and for the last 9 years, I have worked extensively with various power tools and accessories. I have tested hundreds of different brands and models and understand the industry extensively and have been working with tools my entire life!

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